picture
RJR-logo

About | BLOGS | Portfolio | Misc | Recommended | What's New | What's Hot

About | BLOGS | Portfolio | Misc | Recommended | What's New | What's Hot

icon

Bibliography Options Menu

icon
QUERY RUN:
22 Oct 2020 at 01:46
HITS:
10591
PAGE OPTIONS:
Hide Abstracts   |   Hide Additional Links
NOTE:
Long bibliographies are displayed in blocks of 100 citations at a time. At the end of each block there is an option to load the next block.

Bibliography on: Invasive Species

RJR-3x

Robert J. Robbins is a biologist, an educator, a science administrator, a publisher, an information technologist, and an IT leader and manager who specializes in advancing biomedical knowledge and supporting education through the application of information technology. More About:  RJR | OUR TEAM | OUR SERVICES | THIS WEBSITE

RJR: Recommended Bibliography 22 Oct 2020 at 01:46 Created: 

Invasive Species

Standard Definition: Invasive species are plants, animals, or pathogens that are non-native (or alien) to the ecosystem under consideration and whose introduction causes or is likely to cause harm. Although that definition allows a logical possibility that some species might be non-native and harmless, most of time it seems that invasive species and really bad critter (or weed) that should be eradicated are seen as equivalent phrases. But, there is a big conceptual problem with that notion: every species in every ecosystem started out in that ecosystem as an invader. If there were no invasive species, all of Hawaii would be nothing but bare volcanic rock. Without an invasion of species onto land, there would be no terrestrial ecosystems at all. For the entire history of life on Earth, the biosphere has responded to perturbation and to opportunity with evolutionary innovation and with physical movement. While one may raise economic or aesthetic arguments against invasive species, it is impossible to make such an argument on scientific grounds. Species movement — the occurrence of invasive species — is the way the biosphere responds to perturbation. One might even argue that species movement is the primary, short-term "healing" mechanism employed by the biosphere to respond to perturbation — to "damage." As with any healing process, the short-term effect may be aesthetically unappealing (who thinks scabs are appealing?), but the long-term effects can be glorious.

Created with PubMed® Query: "invasive species" OR "invasion biology" OR "alien species" OR "introduced species" NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

-->

RevDate: 2020-10-21

Zhang Z, Liu Y, Yuan L, et al (2020)

Effect of allelopathy on plant performance: a meta-analysis.

Ecology letters [Epub ahead of print].

Allelopathy (i.e. chemical interactions between plants) is known to affect individual performance, community structure and plant invasions. Yet, a quantitative synthesis is lacking. Here, we performed a meta-analysis of 384 studies that measured allelopathic effects of one species (allelopathy plant) on another species or itself (test plant). Overall, allelopathy reduced plant performance by 25%, but the variation in allelopathy was high. The type of method affected the allelopathic effect: compared to leachates, allelopathy was more negative when residues of allelopathy plants were applied, and less negative when soil conditioned by allelopathy plants was applied. The negative effects of allelopathy diminished with study duration, and increased with concentrations of leachates or residues. Although allelopathy was not significantly related to lifespan, life form or domestication of the interacting plants, it became more negative with increasing phylogenetic distance. Moreover, native plants suffered more from leachates of naturalised alien plants than from leachates of other native plants. Our synthesis reveals that allelopathy could contribute to success of alien plants. The negative relationship between phylogenetic distance and allelopathy indicates that allelopathy might contribute to coexistence of closely related species (i.e. convergence) or dominance of single species.

RevDate: 2020-10-21

Lioy S, Laurino D, Capello M, et al (2020)

Effectiveness and Selectiveness of Traps and Baits for Catching the Invasive Hornet Vespa velutina.

Insects, 11(10): pii:insects11100706.

Vespa velutina is an invasive hornet that is colonising several countries worldwide, with detrimental effects on multiple components but primarily affecting honey bees and native insect species. Traps for wasps and hornets are commonly used for trapping V. velutina, both for monitoring and control purposes. In this study, we compared the performances of two typologies of traps and baits widely used for trapping this invasive hornet, by evaluating their effectiveness and selectiveness in trapping V. velutina in two sites during two different periods of the year, spring and autumn. The performance of the traps changed in relation to (i) the trap's model, (ii) the bait's typology and (iii) the period of the year. In spring, traps with common beer as bait were more effective and more selective independently of trap's model than the commercial bait that has been tested. On the contrary, in autumn, just one combination of trap and attractant (the commercial trap and bait) achieved higher effectiveness and selectiveness. Despite the underlined variations among traps and baits, overall catches of V. velutina were scanty compared to bycatches of non-target insects, since best performing traps either in term of effectiveness and selectiveness caught 3.65% of the target species in spring and 1.35% in autumn upon the total trapped insects. This highlights the urgent necessity of developing more selective trapping methods for monitoring and particularly for controlling purposes.

RevDate: 2020-10-20

Silva M, Rodríguez I, Barreiro A, et al (2020)

Lipophilic toxins occurrence in non-traditional invertebrate vectors from North Atlantic Waters (Azores, Madeira, and Morocco): Update on geographical tendencies and new challenges for monitoring routines.

Marine pollution bulletin, 161(Pt B):111725 pii:S0025-326X(20)30843-2 [Epub ahead of print].

In the last decades, due to monitoring programs and strict legislation poisoning incidents occurrence provoked by ingestion of naturally contaminated marine organisms has decreased. However, climate change and anthropogenic interference contributed to the expansion and establishment of toxic alien species to more temperate ecosystems. In this work, the coasts of Madeira, São Miguel islands and the northwestern Moroccan coast were surveyed for four groups of lipophilic toxins (yessotoxins, azaspiracids, pectenotoxins, and spirolides), searching for new vectors and geographical tendencies. Twenty-four species benthic organisms were screened using UHPLC-MS/MS technique. We report 19 new vectors for these toxins, six of them with commercial interest (P. aspera, P. ordinaria, C. lampas, P. pollicipes, H. tuberculata and P. lividus). Regarding toxin uptake a south-north gradient was detected. This study contributes to the update of monitoring routines and legislation policies, comprising a wider range of vectors, to better serve consumers and ecosystems preservation.

RevDate: 2020-10-20

Bueno A, Pritsch K, J Simon (2020)

Responses of native and invasive woody seedlings to combined competition and drought are species-specific.

Tree physiology pii:5932445 [Epub ahead of print].

Woody species invasions are a major threat to native communities with intensified consequences during increased periods of summer drought as predicted for the future. Competition for growth-limiting nitrogen (N) between native and invasive tree species might represent a key mechanism underlying the invasion process, because soil water availability and N acquisition of plants are closely linked. To study whether the traits of invasive species provide an advantage over natives in Central Europe in the competition for N under drought, we conducted a greenhouse experiment. We analysed the responses of three native (i.e., Fagus sylvatica, Quercus robur, and Pinus sylvestris) and two invasive woody species (i.e., Prunus serotina and Robinia pseudoacacia) to competition in terms of their organic and inorganic N acquisition, as well as allocation of N to N pools in the leaves and fine roots. In our study, competition resulted in reduced growth and changes in internal N pools in both native and invasive species mediated by the physiological characteristics of the target species, the competitor, as well as soil water supply. N acquisition, however, was not affected by competition indicating that changes in growth and N pools were rather linked to the remobilization of stored N. Drought led to reduced N acquisition, growth and total soluble protein-N levels, while total soluble amino acid-N levels increased, most likely as osmoprotectants as an adaptation to the reduced water supply. Generally, the consequences of drought were enhanced with competition across all species. Comparing the invasive competitors, P. serotina was a greater threat to the native species than R. pseudoacacia. Furthermore, deciduous and coniferous native species affected the invasives differently, with the species-specific responses being mediated by soil water supply.

RevDate: 2020-10-20

Lenzner B, Magallón S, Dawson W, et al (2020)

The role of diversification rates and evolutionary history as a driver of plant naturalization success.

The New phytologist [Epub ahead of print].

Human introductions of species beyond their natural ranges and subsequent establishment are defining features of global environmental change. However, naturalized plants are not uniformly distributed across phylogenetic lineages, with some families contributing disproportionately more to the global alien species pool than others. Additionally, lineages differ in diversification rates and high diversification rates have been associated with characteristics that increase species naturalization success. Here, we investigate the role of diversification rates in explaining the naturalization success of angiosperm plant families. We use five global datasets including native and alien plant species distribution, horticultural use of plants and a time-calibrated angiosperm phylogeny. Using Phylogenetic Generalized Linear Mixed Models, we analysed the effect of diversification rate, different geographical range measures and horticultural use on the naturalization success of plant families. We show that a family's naturalization success is positively associated with its evolutionary history, native range size and economic use. Investigating interactive effects of these predictors shows that native range size and geographic distribution additionally affect naturalization success. High diversification rates and large ranges increase naturalization success especially of temperate families. We suggest this may result from lower ecological specialization in temperate families with large ranges, compared to tropical families with smaller ranges.

RevDate: 2020-10-20

Shi W, Roderick G, GS Zhang (2020)

Mechanisms of Novel Host Use by Bactrocera tau (Tephritid: Diptera) Revealed by RNA Transcriptomes.

Journal of insect science (Online), 20(5):.

Use of novel plant hosts can facilitate the establishment and range expansion of herbivorous invasive species. However, the inherent mechanisms of novel host use are still unclear in many herbivorous species. Here, we examine mechanisms of novel host use in the invasive tephritid fruit fly Bactrocera tau (Walker)(Diptera: Tephritidae) by documenting changes in the RNA transcriptomes associated with a novel host. RNA transcripts of B. tau were obtained with high-throughput sequencing from samples continuously reared on two traditional Cucurbitaceae hosts and a novel host (banana). We found transcriptome variation was strongly associated with feeding on banana. Moreover, B. tau feeding on banana contained more differentially expressed genes (DEGs) and more annotated categories of DEGs in the Kyoto Encyclopedia of Genes and Genomes (KEGG) database with 1,595 DEGs and 21 major annotated pathways. The annotated categories of DEGs in individuals reared on banana differed with from those individuals feeding on other hosts and were enriched in oxidative phosphorylation, citrate cycle pathway, and four other carbohydrate pathways. For B. tau feeding on banana, the predominant numbers of upregulated genes in the mitochondrial NADH (56 on average) and a relatively higher numbers of upregulated genes (13 on average) were found in oxidative phosphorylation and the TCA pathway, respectively. Changes in RNA transcriptomes associated with novel host use, especially for genes related to energy and carbohydrate metabolism, help to explain how B. tau can be successful in use of novel hosts and may be useful in developing novel strategies for control of tephritid flies.

RevDate: 2020-10-20

Guevara-Molina EC, Gomes FR, A Camacho (2020)

Effects of dehydration on thermoregulatory behavior and thermal tolerance limits of Rana catesbeiana ().

Journal of thermal biology, 93:102721.

Predicting the effects of high environmental temperatures and drought on populations requires understanding how these conditions will influence the thermoregulatory behavior and thermal tolerance of organisms. Ectotherms show proportional (fine-tuned) and all-or-none (abrupt) responses to avoid overheating. Scattered evidence suggests that dehydration alters these behavioral responses and thermal tolerance, but these effects have not been evaluated in an integrative manner. We examined the effects of hydration level on the behavioral thermoregulation and behavioral and physiological thermal limits of the "bullfrog" (Rana catesbeiana), a well-studied and important invasive species. To examine the effects of dehydration on proportional responses, we compared the Preferred Body Temperatures (PBT) of frogs with restricted and unrestricted access to water. To assess the effect of dehydration on all-or-none responses, we measured and compared the Voluntary Thermal Maximum (VTMax) at different hydration levels (100%, 90%, 80% of body weight at complete hydration). Finally, to understand the effect of dehydration on physiological thermal tolerance, we measured the Critical Thermal Maximum (CTMax) of frogs at matched hydration levels. PBT, VTMax, and CTMax all decreased in response to higher dehydration levels. However, bullfrogs changed their PBT more than their VTMax or CTMax in response to dehydration. Moreover, some severely dehydrated individuals did not exhibit a VTMax response. We discuss the implications of our results in the context of plasticity of thermoregulatory responses and thermal limits, and its potential application to mechanistic modeling.

RevDate: 2020-10-19

Miller KM, McGill BJ, Weed AS, et al (2020)

Long-term trends indicate that invasive plants are pervasive and increasing in eastern national parks.

Ecological applications : a publication of the Ecological Society of America [Epub ahead of print].

While invasive plant distributions are relatively well known in the eastern United States, temporal changes in species distributions and interactions among species have received little attention. Managers are therefore left to make management decisions without knowing which species pose the greatest threats based on their ability to spread, persist and outcompete other invasive species. To fill this gap, we used the US National Park Service's Inventory and Monitoring Program data collected from over 1400 permanent forest plots spanning 12 years and covering 39 eastern national parks to analyze invasive plant trends. We analyzed trends in abundance at multiple scales, including plot frequency, quadrat frequency and average quadrat cover. We examined trends overall, by functional group, and by species. We detected considerably more increasing than decreasing trends in invasive plant abundance. In fact, 80% of the parks in our study had at least one significant increasing trend in invasive abundance over time. Where detected, significant negative trends tended to be herbaceous or graminoid species. However, these declines were often countered by roughly equivalent increases in invasive shrubs over the same time period, and we only detected overall declines in invasive abundance in two parks in our study. Present in over 30% of plots and responsible for the steepest and greatest number of significant increases, Japanese stiltgrass (Microstegium vimineum) was the most aggressive invader in our study and is a high management priority. Invasive shrubs, especially Japanese barberry (Berberis thunbergii), Japanese honeysuckle (Lonicera japonica), multiflora rose (Rosa multiflora), and wineberry (Rubus phoenicolasius), also increased across multiple parks, and sometimes at the expense of Japanese stiltgrass. Given the added risks to human health from tick-borne diseases, invasive shrubs are a high management priority. While these findings provide critical information to managers for species prioritization, they also demonstrate the incredible management challenge that invasive plants pose in protected areas, particularly since we documented few overall declines in invasive abundance. As parks work to overcome deferred maintenance of infrastructure, our findings suggest that deferred management of natural resources, particularly invasive species, requires similar attention and long-term commitment to reverse these widespread increasing invasive trends.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Aguin-Pombo D, N Freitas (2020)

Empoasca fabalis (Hemiptera: Cicadellidae): first report of an invasive pest of sweet potatoes in Portugal (Madeira Island).

Zootaxa, 4838(1):zootaxa.4838.1.9 pii:zootaxa.4838.1.9.

The genus Empoasca comprises more than 600 species, many of them important pests of cultivated plants. The leafhopper Empoasca fabalis DeLong, 1930 is native to the tropical and subtropical regions of America. From here, it has successfully spread to most regions of the continent. Today its range extends from the southern United States, through Central America, and the West Indies to southern South America (Cusipuma Sanchez 1993, DeLong 1930, Paradell et al. 1990, Poos Wheeler 1949, Wolcott, 1948). Outside its native area, the species was more recently recorded in the Canary Islands (Lorenzo Hermoso de Mendonza 2000) and Hawaii (Dietrich Perreira 2019). Although it is still not known to occur in the European mainland, specimens were collected in 2000 on the island of La Palma (Spain) (Lorenzo Hermoso de Mendonza, 2000). Until now, it was unknown on the island of Madeira and Portugal.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Wang Z, Nong D, Countryman AM, et al (2020)

Potential impacts of ballast water regulations on international trade, shipping patterns, and the global economy: An integrated transportation and economic modeling assessment.

Journal of environmental management, 275:110892.

Global ballast water management regulations aiming to decrease aquatic species invasion require actions that can increase shipping costs. We employ an integrated shipping cost and global economic modeling approach to investigate the impacts of ballast water regulations on bilateral trade, national economies, and shipping patterns. Given the potential need for more stringent regulation at regional hotspots of species invasions, this work considers two ballast water treatment policy scenarios: implementation of current international regulations, and a possible stricter regional regulation that targets ships traveling to and from the United States while other vessels continue to face current standards. We find that ballast water management compliance costs under both scenarios lead to modest negative impacts on international trade and national economies overall. However, stricter regulations applied to U.S. ports are expected to have large negative impacts on bilateral trade of several specific commodities for a few countries. Trade diversion causes decreased U.S. imports of some products, leading to minor economic welfare losses.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Eskew EA, White AM, Ross N, et al (2020)

United States wildlife and wildlife product imports from 2000-2014.

Scientific data, 7(1):22.

The global wildlife trade network is a massive system that has been shown to threaten biodiversity, introduce non-native species and pathogens, and cause chronic animal welfare concerns. Despite its scale and impact, comprehensive characterization of the global wildlife trade is hampered by data that are limited in their temporal or taxonomic scope and detail. To help fill this gap, we present data on 15 years of the importation of wildlife and their derived products into the United States (2000-2014), originally collected by the United States Fish and Wildlife Service. We curated and cleaned the data and added taxonomic information to improve data usability. These data include >2 million wildlife or wildlife product shipments, representing >60 biological classes and >3.2 billion live organisms. Further, the majority of species in the dataset are not currently reported on by CITES parties. These data will be broadly useful to both scientists and policymakers seeking to better understand the volume, sources, biological composition, and potential risks of the global wildlife trade.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Marini F, Caputo B, Pombi M, et al (2019)

Estimating Spatio-Temporal Dynamics of Aedes Albopictus Dispersal to Guide Control Interventions in Case of Exotic Arboviruses in Temperate Regions.

Scientific reports, 9(1):10281 pii:10.1038/s41598-019-46466-4.

The increasing number of exotic arbovirus cases imported in Europe and the 2017 chikungunya outbreak in central/southern Italy highlight the urgency of evidence-based outbreak management plans to predict, prevent or interrupt spreading of these arboviruses to non-endemic countries in temperate regions. We here present the results of three mark-release-recapture experiments conducted in a peri-urban area of North-East Italy to estimate the spatio-temporal dynamics of the dispersal of Aedes albopictus females looking for oviposition sites. The Flight Range of 90% of the mosquito population (FR90) was found to exceed 200 m, consistently with data obtained from a previous study conducted in a highly urbanised area in Rome (Central Italy). Modelling results showed that dispersal can be so rapid that insecticide spraying within a 200m-radius around a potential infected case leaves >10% probability that a potentially infected mosquito escapes the treatment, even if this is carried out after only 2-3 days since the importation of a viremic case. These data provide evidence in favour of an update of guidelines for the control of exotic autochthonous arbovirus transmission in temperate areas and highlight the need of effective surveillance approaches and rapid response to contain the risks associated to imported viremic cases.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Wieczorek K, Fulcher TK, D Chłond (2019)

The composition of the aphid fauna (Insecta, Hemiptera) of the Royal Botanic Gardens, Kew.

Scientific reports, 9(1):10000 pii:10.1038/s41598-019-46441-z.

At least a dozen species of aphids (Insecta, Hemiptera) of non-native origin have expanded their range in Europe, however the importance of botanic gardens in this phenomenon has not been studied previously in detail. As a case study, investigations on the species composition and host range of Aphidomorpha in the Royal Botanic Gardens, Kew, London, United Kingdom, were conducted over a period of twelve days, in June 2017. The inventory study was carried out in the collection of living plants, both in the gardens and the glasshouses and nurseries. In total, 94 taxa of Aphidomorpha are identified (one phylloxerid, one adelgid and 92 species of aphids). 20 species are regarded as alien to the European aphid fauna and among them nine are believed to be the first published records for Kew. 20 species are regarded as serious pests, capable of virus transmission. The list of host plants includes 155 taxa from 89 genera and 49 families. Ericolophium holsti (Takahashi), species of Asiatic origin associated with Rhododendron spp., was found for the first time in the field in the UK. Changes in the species composition of the aphid fauna in reference to the Eastop's studies in 1960s were discussed.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Falkenberg LJ, Styan CA, JN Havenhand (2019)

Sperm motility of oysters from distinct populations differs in response to ocean acidification and freshening.

Scientific reports, 9(1):7970 pii:10.1038/s41598-019-44321-0.

Species' responses to climate change will reflect variability in the effects of physiological selection that future conditions impose. Here, we considered the effects of ocean acidification (increases in pCO2; 606, 925, 1250 µatm) and freshening (reductions in salinity; 33, 23, 13 PSU) on sperm motility in oysters (Crassostrea gigas) from two populations (one recently invaded, one established for 60+ years). Freshening reduced sperm motility in the established population, but this was offset by a positive effect of acidification. Freshening also reduced sperm motility in the recently invaded population, but acidification had no effect. Response direction, strength, and variance differed among individuals within each population. For the established population, freshening increased variance in sperm motility, and exposure to both acidification and freshening modified the performance rank of males (i.e. rank motility of sperm). In contrast, for the recently invaded population, freshening caused a smaller change in variance, and male performance rank was broadly consistent across treatments. That inter-population differences in response may be related to environmental history (recently invaded, or established), indicates this could influence scope for selection and adaptation. These results highlight the need to consider variation within and among population responses to forecast effects of multiple environmental change drivers.

RevDate: 2020-10-19

Can-Vargas X, Barboza N, Fuchs EJ, et al (2020)

Spatial Distribution of Whitefly Species (Hemiptera: Aleyrodidae) and Identification of Secondary Bacterial Endosymbionts in Tomato Fields in Costa Rica.

Journal of economic entomology pii:5930138 [Epub ahead of print].

In Costa Rica, tomato (Solanum lycopersicum Linnaeus) Linnaeus (Solanales: Solanaceae) is one of the crops most severely affected by the whiteflies (Hemiptera: Aleyrodidae) Trialeurodes vaporariorum (Westwood) and the Bemisia tabaci (Gennadius) species complex. The objective of this study was to monitor the spatial distribution and diversity of these species and to detect the presence of secondary bacterial endosymbionts in individuals collected in areas of intensive tomato production. In total, 628 whitefly individuals were identified to the species level using restriction analysis (PCR-RFLP) of a fragment of the mitochondrial cytochrome C oxidase I gene (mtCOI). Trialeurodes vaporariorum was the predominant species, followed by B. tabaci Mediterranean (MED). Bemisia tabaci New World (NW) and B. tabaci Middle East-Asia Minor 1 (MEAM1) were present in lower numbers. The mtCOI fragment was sequenced for 89 individuals and a single haplotype was found for each whitefly species. Using molecular markers, the 628 individuals were analyzed for the presence of four endosymbionts. Arsenophonus Gherna et al. (Enterobacterales: Morganellaceae) was most frequently associated with T. vaporariorum, whereas Wolbachia Hertig (Rickettsiales: Anaplasmataceae) and Rickettsia da Rocha-Lima (Rickettsiales: Rickettsiaceae) were associated with B. tabaci MED. This study confirmed that B. tabaci NW has not been completely displaced by the invasive species B. tabaci MED and B. tabaci MEAM1 present in the country. An association was found between whitefly species present in tomato and certain secondary endosymbionts, elevation was the most likely environmental factor to affect their frequency.

RevDate: 2020-10-19

Westby KM, Juliano SA, KA Medley (2020)

Aedes albopictus (Diptera: Culicidae) Has Not Become the Dominant Species in Artificial Container Habitats in a Temperate Forest More Than a Decade After Establishment.

Journal of medical entomology pii:5930033 [Epub ahead of print].

Aedes albopictus (Skuse) (Diptera: Culicidae) is one of the most invasive species globally, and has led to rapid declines and local extirpations of resident mosquitoes where it becomes established. A potential mechanism behind these displacements is the superior competitive ability of Ae. albopictus in larval habitats. Research on the context-dependent nature of competitive displacement predicts that Ae. albopictus will not replace native Aedes triseriatus (Say) (Diptera: Culicidae) in treeholes but could do so in artificial container habitats. Aedes albopictus remains rare in temperate treeholes but less is known about how Ae. albopictus fares in artificial containers in forests. Tyson Research Center (TRC) is a field station composed of mostly oak-hickory forest located outside Saint Louis, MO. The container community has been studied regularly at TRC since 2007 with permanently established artificial containers on the property since 2013. Aedes albopictus was detected each year when these communities were sampled; however, its abundance remains low and it fails to numerically dominate other species in these communities. We present data that show Ae. albopictus numbers have not increased in the last decade. We compare egg counts from 2007 to 2016 and combine larval sample data from 2012 to 2017.We present average larval densities and prevalence of Ae. albopictus and two competitors, Ae. triseriatus and Aedes japonicus (Theobald) (Diptera: Culicidae), as well as monthly averages by year. These data highlight a circumstance in which Ae. albopictus fails to dominate the Aedes community despite it doing so in more human-impacted habitats. We present hypotheses for these patterns based upon abiotic and biotic environmental conditions.

RevDate: 2020-10-19

Lucero JE, Arab NM, Meyer ST, et al (2020)

Escape from natural enemies depends on the enemies, the invader, and competition.

Ecology and evolution, 10(19):10818-10828 pii:ECE36737.

The enemy release hypothesis (ERH) attributes the success of some exotic plant species to reduced top-down effects of natural enemies in the non-native range relative to the native range. Many studies have tested this idea, but very few have considered the simultaneous effects of multiple kinds of enemies on more than one invasive species in both the native and non-native ranges. Here, we examined the effects of two important groups of natural enemies-insect herbivores and soil biota-on the performance of Tanacetum vulgare (native to Europe but invasive in the USA) and Solidago canadensis (native to the USA but invasive in Europe) in their native and non-native ranges, and in the presence and absence of competition.In the field, we replicated full-factorial experiments that crossed insecticide, T. vulgare-S. canadensis competition, and biogeographic range (Europe vs. USA) treatments. In greenhouses, we replicated full-factorial experiments that crossed soil sterilization, plant-soil feedback, and biogeographic range treatments. We evaluated the effects of experimental treatments on T. vulgare and S. canadensis biomass.The effects of natural enemies were idiosyncratic. In the non-native range and relative to populations in the native range, T. vulgare escaped the negative effects of insect herbivores but not soil biota, depending upon the presence of S. canadensis; and S. canadensis escaped the negative effects of soil biota but not insect herbivores, regardless of competition. Thus, biogeographic escape from natural enemies depended upon the enemies, the invader, and competition. Synthesis: By explicitly testing the ERH in terms of more than one kind of enemy, more than one invader, and more than one continent, this study enhances our nuanced perspective of how natural enemies can influence the performance of invasive species in their native and non-native ranges.

RevDate: 2020-10-19

Bowen AKM, MHH Stevens (2020)

Temperature, topography, soil characteristics, and NDVI drive habitat preferences of a shade-tolerant invasive grass.

Ecology and evolution, 10(19):10785-10797 pii:ECE36735.

Aim: Despite the large literature documenting the negative effects of invasive grasses, we lack an understanding of the drivers of their habitat suitability, especially for shade-tolerant species that do not respond positively to canopy disturbance. We aimed to understand the environmental niche and potential spatial distribution of a relatively new invasive species, wavyleaf basketgrass (Oplismenus undulatifolius (Ard.) Roem. & Schult, WLBG) by leveraging data available at two different spatial scales.

Location: Mid-Atlantic region of the United States.

Methods: Maximum entropy modeling (Maxent) was used to predict the habitat suitability of WLBG at the regional scale and the landscape scale. Following variable evaluation, model calibration, and model evaluation, final models were created using 1,000 replicates and projected to each study area.

Results: At the regional scale, our best models show that suitability for WLBG was driven by relatively high annual mean temperatures, low temperature seasonality and monthly range, low slope, and high cumulative Normalized Difference Vegetation Index (NDVI). At the landscape scale, suitability was highest near roads and streams, far from trails, at low elevations, in sandy, moist soil, and in areas with high NDVI.

Main Conclusions: We found that invasion potential of this relatively new invader appears high in productive, mesic habitats at low slope and elevations. At the regional scale, our model predicted areas of suitable habitat far outside areas where WLBG has been reported, including large portions of Virginia and West Virginia, suggests serious potential for spread. However, large portions of this area carry a high extrapolation risk and should therefore be interpreted with caution. In contrast, at the landscape level, the suitability of WLBG is largely restricted to areas near current presence points, suggesting that the expansion risk of this species within Shenandoah National Park is somewhat limited.

RevDate: 2020-10-19

Wooley SC, Smith DS, Lonsdorf EV, et al (2020)

Local adaptation and rapid evolution of aphids in response to genetic interactions with their cottonwood hosts.

Ecology and evolution, 10(19):10532-10542 pii:ECE36709.

Several studies have demonstrated the ecological consequences of genetic variation within a single plant species. For example, these studies show that individual plant genotypes support unique composition of the plants' associated arthropod community. By contrast, fewer studies have explored how plant genetic variation may influence evolutionary dynamics in the plant's associated species. Here, we examine how aphids respond evolutionarily to genetic variation in their host plant. We conducted two experiments to examine local adaptation and rapid evolution of the free-feeding aphid Chaitophorus populicola across genetic variants of its host plant, Populus angustifolia. To test for local adaptation, we collected tree cuttings and aphid colonies from three sites along an elevation/climate gradient and conducted a reciprocal transplant experiment. In general, home aphids (aphids transplanted onto trees from the same site) produced 1.7-3.4 times as many offspring as foreign aphids (aphids transplanted onto trees from different sites). To test for rapid evolution, we used 4 clonally replicated aphid genotypes and transplanted each onto 5 clonally replicated P. angustifolia genotypes. Each tree genotype started with the same aphid genotype composition. After 21 days (~two aphid generations), aphid genotype composition changed (i.e., aphids evolved) and some tree genotypes supported unique evolutionary trajectories of aphids. These results suggest that plant evolution in response to human perturbation, such as climate change and invasive species, will also result in evolutionary responses in strongly interacting species that could cascade to affect whole communities.

RevDate: 2020-10-19

Poveda-Martínez D, Aguirre MB, Logarzo G, et al (2020)

Species complex diversification by host plant use in an herbivorous insect: The source of Puerto Rican cactus mealybug pest and implications for biological control.

Ecology and evolution, 10(19):10463-10480 pii:ECE36702.

Cryptic taxa have often been observed in the form of host-associated species that diverged as the result of adaptation to alternate host plants. Untangling cryptic diversity in species complexes that encompass invasive species is a mandatory task for pest management. Moreover, investigating the evolutionary history of a species complex may help to understand the drivers of their diversification. The mealybug Hypogeococcus pungens was believed to be a polyphagous species from South America and has been reported as a pest devastating native cacti in Puerto Rico, also threatening cactus diversity in the Caribbean and North America. There is neither certainty about the identity of the pest nor the source population from South America. Recent studies pointed to substantial genetic differentiation among local populations, suggesting that H. pungens is a species complex. In this study, we used a combination of genome-wide SNPs and mtDNA variation to investigate species diversity within H. pungens sensu lato to establish host plant ranges of each one of the putative members of the complex, to evaluate whether the pattern of host plant association drove diversification in the species complex, and to determine the source population of the Puerto Rican cactus pest. Our results suggested that H. pungens comprises at least five different species, each one strongly associated with specific host plants. We also established that the Puerto Rican cactus pest derives from southeastern Brazilian mealybugs. This is an important achievement because it will help to design reliable strategies for biological control using natural enemies of the pest from its native range.

RevDate: 2020-10-19

Roznik EA, Surbaugh KL, Cano N, et al (2020)

Elucidating mechanisms of invasion success: effects of parasite removal on growth and survival rates of invasive and native frogs.

The Journal of applied ecology, 57(6):1078-1088.

Identifying the mechanisms underlying biological invasions can inform the management of invasive species. The enemy release hypothesis (ERH) suggests that invasive species have a competitive advantage in their introduced range because they leave behind many of their predators and parasites from their native range, allowing them to shift resources from defenses to growth, reproduction, and dispersal. Many studies have demonstrated that invasive species have fewer parasites than their native counterparts, but few studies have tested whether the loss of these natural enemies appears to be a primary driver of the invasion process.To test the ERH, we conducted a mark-recapture study in which we used an anthelmintic drug to successfully reduce parasitic worms in invasive Cuban treefrogs (Osteopilus septentrionalis) and native treefrogs (Hyla spp.) at half of 12 wetlands, marking nearly 4,200 frogs. If the ERH is supported, we would expect that treating for parasitic worms would have a greater benefit to native than invasive hosts.Growth and survival rates of invasive and native treefrogs responded similarly to the anthelmintic treatment, suggesting that the Cuban treefrog's release from parasitic worms does not appear to significantly contribute to its invasiveness in established areas. Instead, it appears that the overall faster rates of growth and maturation, higher survival rates, and larger body sizes of Cuban treefrogs that we observed may contribute to their expansion and proliferation.Synthesis and applications. Although Cuban treefrogs have a lower diversity of parasitic worms in their invasive than native range, this does not appear to significantly contribute to their invasion success in areas where they have been established for more than 20 years. This suggests that any manipulation of parasites in invasive or native hosts would not be an effective method of controlling Cuban treefrogs or reducing their impacts. Further research into other hypotheses is needed to explain the Cuban treefrog's success and help guide management actions to reduce their spread and negative impacts. Our study demonstrates that enemy release may not be a primary driver of invasiveness, highlighting the need for more experimental tests of the enemy release hypothesis to examine its generality.

RevDate: 2020-10-19

Dissegna A, Caputi A, C Chiandetti (2020)

Long-lasting generalization triggered by a single trial event in the invasive crayfish Procambarus clarkii.

The Journal of experimental biology pii:jeb.227827 [Epub ahead of print].

Behavioural flexibility allows to adapt to environmental changes, a situation that invasive species have often to face when colonizing new territories. Such flexibility is ensued by a set of cognitive mechanisms among which generalization plays a key role, as it allows to transfer past solution to solve similar new problems. By means of a habituation paradigm, we studied generalization in the invasive crayfish Procambarus clarkii. Once crayfish habituated their alarming response to a specific water jet, we tested whether habituation transferred to a new type of water jet. Although habituation did not generalize when the new stimulus was initially presented, it surprisingly emerged 15 and 45 days later. Hence, remarkably, in P. clarkii a single presentation of a new event was sufficient to trigger a long-lasting form of learning generalization from previous similar stimuli, a cognitive ability that may concur in providing adaptive advantages to this invasive species.

RevDate: 2020-10-17

Keyler DE, Ahmad M, Rodriguez A, et al (2020)

Latrodectus geometricus (Aranea: Theridiidae) envenoming: Rapid resolution of symptoms following F(ab')2 antivenom therapy.

The Brown Widow spider (Latrodectus geometricus) is an invasive species whose geographic range has been expanding worldwide. It is a relative species of the Black Widow and Red-backed spiders of the genus Latrodectus. Despite its broad geographic distribution cases of Brown Widow envenomation have rarely been documented. The venom of L. geometricus is similar to the venom of L. mactans with the primary venom component being alpha-latrotoxin, and consequent envenoming by L. geometricus to humans has resulted in symptoms similar to those reported for other Latrodectus spp. Specific FDA approved Latrodectus antivenom (IgG) available in North America has been effectively used in treating venom-induced symptoms following L. mactans envenoming. The patient reported here involved a confirmed L. geometricus envenoming who was efficaciously treated with an alternately available F(ab')2 antivenom from Mexico.

RevDate: 2020-10-17

Anton A (2020)

How many alien species will there be in 2050?.

Global change biology [Epub ahead of print].

The introduction of non-native species into new regions is on the rise due to humanity's increasing global connectivity (Seebens et al., 2017). Many studies have identified the widespread ecological, economic, and social damage that these alien species can cause (Doherty et al., 2016; Hoffmann & Broadhurst, 2016). Advanced statistical analysis has recently been employed to predict ecological patterns of alien species, such as how alien species may be globally distributed in the future. Previous studies that have attempted to answer this question have been restricted to single species, taxa, or regions (Seebens et al., 2015, 2016).

RevDate: 2020-10-17

Vázquez AA, Sabourin E, Alda P, et al (2020)

Genetic diversity and relationships of the liver fluke Fasciola hepatica (Trematoda) with native and introduced definitive and intermediate hosts.

Transboundary and emerging diseases [Epub ahead of print].

Fasciolosis is a worldwide spread parasitosis mainly caused by the trematode Fasciola hepatica. This disease is particularly important for public health in tropical regions but it can also affect the economies of many developed countries due to large infections in domestic animals. Although several studies have tried to understand the transmission by studying the prevalence of different host species, only a few have used population genetics approaches to understand the links between domestic and wildlife infections. Here we present the results of such genetic approach combined with classical parasitological data (prevalence and intensity) by studying domestic and wild definitive hosts from Camargue (southern France) where fasciolosis is considered as a problem. We found 60% of domestic hosts (cattle) infected with F. hepatica but lower values in wild hosts (nutria, 19%; wild boars, 4.5%). We explored nine variable microsatellite loci for 1,148 adult flukes recovered from four different populations (non-treated cattle, treated cattle, nutria and wild boars). Populations from the four groups differed, though we found a number of migrants particularly non-treated cattle and nutria. Overall, we detected 729 different multilocus genotypes (from 783 completely genotyped individuals) and only 46 genotypes repeated across samples. Finally, we experimentally infected native and introduced intermediate snail hosts to explore their compatibility with F. hepatica and assess the risks of fasciolosis expansion in the region. The introduced species G. truncatula and P. columella attained the higher values of overall compatibility in relation to the European species. However, concerning the origin, sympatric combinations of G. truncatula were more compatible (higher prevalence, intensity and survival) than the allopatric tested. According to our results, we should note that the assessment of epidemiological risks cannot be limited to a single host-parasite system, but should focus on understanding the diversity of hosts in the heterogeneous environment through space and time.

RevDate: 2020-10-16

Blackwell T, Ford AGP, Ciezarek AG, et al (2020)

Newly discovered cichlid fish biodiversity threatened by hybridization with non-native species.

Molecular ecology [Epub ahead of print].

Invasive freshwater fishes are known to readily hybridize with indigenous congeneric species, driving loss of unique and irreplaceable genetic resources. Here we reveal that newly discovered (2013-2016) evolutionarily significant populations of Korogwe tilapia (Oreochromis korogwe) from southern Tanzania are threatened by hybridization with the larger invasive Nile tilapia (Oreochromis niloticus). We use a combination of morphology, microsatellite allele frequencies and whole genome sequences to show that O. korogwe from southern lakes (Nambawala, Rutamba and Mitupa) are distinct from geographically disjunct populations in northern Tanzania (Zigi River and Mlingano Dam). We also provide genetic evidence of O. korogwe × niloticus hybrids in three southern lakes and demonstrate heterogeneity in the extent of admixture across the genome. Finally, using the least admixed genomic regions we estimate that the northern and southern O. korogwe populations most plausibly diverged ~140,000 years ago, suggesting that the geographical separation of the northern and southern groups is not a result of a recent translocation, and instead these populations represent independent evolutionarily significant units. We conclude that these newly discovered and phenotypically unique cichlid populations are already threatened by hybridization with an invasive species, and propose that these irreplaceable genetic resources would benefit from conservation interventions.

RevDate: 2020-10-16

Mateos E, Jones HD, Riutort M, et al (2020)

A new species of alien terrestrial planarian in Spain: Caenoplana decolorata.

PeerJ, 8:e10013 pii:10013.

Terrestrial planarians found in a plant nursery in Spain in 2012 are described as a new species, Caenoplana decolorata. Dorsally they are mahogany brown with a cream median line. Ventrally they are pastel turquoise fading to brown laterally. Molecular data indicate that they are a member of the genus Caenoplana, but that they differ from other Caenoplana species found in Europe. One mature specimen has been partially sectioned, and the musculature and copulatory apparatus is described, confirming the generic placement but distinguishing the species from other members of the genus. It is probable that the species originates from Australia.

RevDate: 2020-10-16

Pokhrel MR, Cairns SC, NR Andrew (2020)

Dung beetle species introductions: when an ecosystem service provider transforms into an invasive species.

PeerJ, 8:e9872 pii:9872.

Dung beetle introduction programmes were designed to accelerate exotic livestock dung degradation and to control dung breeding pestiferous flies and livestock parasites. The introduction programmes provided exotic dung beetle species with an opportunity to cross natural barriers and spread beyond their native range. There are no reports that explain what probable adaptation mechanisms enable particular dung beetle species to be the most successful invader. Here we identify the morphological, biological, physiological, ecological and behavioural attributes of the four most widespread and successful dung beetle species in introduced areas on a global scale in relation to the assumption that these species are different from other exotic and native dung beetles. We have recognised Digitonthophagus gazella (Fabricius), Onthophagus taurus (Schreber), Euoniticellus intermedius (Reiche) and Aphodius fimetarius (Linnaeus) as the most successful invaders based on their spread, predominance, distribution range and the reports of invasion. Each of these four species has different natural history traits that increase their fitness making them successful invaders. D. gazella has high fecundity and spreading ability, can instantly locate and colonise fresh and nutritious dung, and has a broad thermal window. O. taurus has morphological plasticity, high fecundity, high brood survival rate due to bi-parenting, and is adapted to extreme thermal and moisture conditions. E. intermedius has remnant-dung feeding abilities, a wide thermal window, functioning best at upper-temperature levels, and successful breeding and survival abilities at extremely low soil moisture conditions. A. fimetarius is small-sized, has high breeding and dispersal abilities, and is adapted to lower thermal and upper moisture extremes and variable soil conditions. Discussed here are perspectives on adaptive attributes of dung beetle species that are important to consider during their selection for redistributions. We have elaborated on the fitness and success characteristics of the four species individually. Further, we recommend a prior-introduction baseline monitoring of native dung beetle assemblages so as to evaluate the future impact of exotic dung beetle introductions on the recipient ecosystem.

RevDate: 2020-10-16

Bates OK, Ollier S, C Bertelsmeier (2020)

Smaller climatic niche shifts in invasive than non-invasive alien ant species.

Nature communications, 11(1):5213 pii:10.1038/s41467-020-19031-1.

The globalization of trade and human movement has resulted in the accidental dispersal of thousands of alien species worldwide at an unprecedented scale. Some of these species are considered invasive because of their extensive spatial spread or negative impacts on native biodiversity. Explaining which alien species become invasive is a major challenge of invasion biology, and it is often assumed that invasiveness is linked to a greater ability to establish in novel climates. To test whether invasive species have expanded more into novel climates than non-invasive alien species, we quantified niche shifts of 82 ant species. Surprisingly, invasive species showed smaller niche shifts than non-invasive alien species. Independent of their invasiveness, the species with the smallest native niches and range sizes, experienced the greatest niche shifts. Overall, our results challenge the assumption that invasive species are particularly good pioneers of novel climates.

RevDate: 2020-10-15

Geldert C, Abdo Z, Stewart JE, et al (2020)

Dietary Supplementation with Phytochemicals Improves Diversity and Abundance of Honey Bee Gut Microbiota.

Journal of applied microbiology [Epub ahead of print].

AIM: Determine the impact of beneficial phytochemicals on diversity and abundance of the gut microbiome in the honey bee (Apis mellifera).

METHODS AND RESULTS: Eight-day old honey bees were fed 25 ppm of phytochemical (caffeine, gallic acid, p-coumaric acid, or kaempferol) in 20% sucrose. Guts of bees collected at 3 and 6 days were excised and subjected to Next Generation sequencing for bacterial 16S and fungal ITS regions. Although phytochemical supplementation fostered gut microbial diversity and abundance, the patterns differed between phytochemicals and there was a temporal stabilization of the bacterial community. While, bacterial and fungal communities responded differently, all phytochemical treatments displayed increased abundance of the most represented bacterial genera, Snodgrassella spp and Lactobacillus spp.

CONCLUSIONS: Phytochemical supplementation improves gut microbial diversity and abundance, reiterating the need for diverse habitats that provide bees with access to pollen and nectar rich in these micronutrients. Diverse gut microbiota can improve bee defenses against biotic stressors and worker bee lifespan.

This is the first report on the impact of phytochemical supplementation on gut microbiota in honey bees and these findings have implications for strategic hive management through standardization of effective phytochemical and probiotic feed supplements.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Ferreira VG, Higuti J, K Martens (2020)

Taxonomic revision of Strandesia s.s. (Crustacea, Ostracoda) from four Brazilian floodplains, with the description of three new species.

Zootaxa, 4760(1):zootaxa.4760.1.1 pii:zootaxa.4760.1.1.

The present paper is a contribution to the taxonomy of the genus Strandesia. Here, we describe three new species: S. thomazi nov. sp., S. galeati nov. sp. and S. nakatanii nov. sp. We also describe the male of Strandesia obtusata (Sars, 1901); this is the first record of sexual populations of a Brazilian Strandesia species. Nine other Strandesia species from the Amazon, Araguaia, Pantanal and Paraná river floodplains are redescribed. We also propose that Strandesia trichosa Roessler, 1990 is a synonym of Strandesia psittacea Sars, 1901. Most of the species analyzed here are endemic to the Neotropical region, with the exception of Strandesia bicuspis (Claus, 1892) G.W. Müller, which occurs also (as an alien invasive species) in the Palaearctic. This genus occurs in water bodies with a wide range of abiotic variables and in many different aquatic macrophyte species. The species analyzed here have a highly conservative soft part morphology, but an impressive variety of carapace shapes.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Nel WJ, DE Beer ZW, Wingfield MJ, et al (2020)

The granulate ambrosia beetle, Xylosandrus crassiusculus (Coleoptera: Curculionidae, Scolytinae), and its fungal symbiont found in South Africa.

Zootaxa, 4838(3):zootaxa.4838.3.7 pii:zootaxa.4838.3.7.

Xylosandrus crassiusculus (Motchulsky) is a native Asian ambrosia beetle that has been accidentally introduced to many countries of the world, presumably through the international movement of nursery, timber, and wood products. The species is known in various tropical African countries but only as far south as Tanzania on the African continent. In this study, we report X. crassiusculus and its fungal symbiont for the first time from South Africa. The species was identified using both morphological characters and COI sequence data. Xylosandrus crassiusculus were obtained from three different provinces of South Africa and represent two distinct haplotypes. The fungal symbiont, Ambrosiella roeperi, was isolated and identified using DNA sequencing and morphological characterization.

RevDate: 2020-10-19
CmpDate: 2020-10-19

ErdoĞan-Dereli D, ME Çinar (2020)

The diversity of the genus Aricidea (Polychaeta: Paraonidae) from the Sea of Marmara, with descriptions of two new species and two new records for the Mediterranean fauna.

Zootaxa, 4844(1):zootaxa.4844.1.1 pii:zootaxa.4844.1.1.

This paper reports 13 Aricidea species from the Sea of Marmara. The Aricidea specimens were collected at 98 stations in the region in 2012 and 2013 from soft and hard substrata at depths ranging from 0 to 1200 m. Among the material, two new species, namely Aricidea (Acmira) katzmanni n. sp. and Aricidea (Acmira) pseudoassimilis n. sp., and 11 known species were discovered. Aricidea mirunekoa and A. bulbosa are new records for the Mediterranean fauna; A. (Acmira) annae and A. (Aricidea) wassi are new records for the Sea of Marmara. Aricidea (Acmira) katzmanni n. sp. is characterized by having a long, digitiform antenna; no notopodial papillae on the posterior part of the branchial region; and hook shaped modified neurochaetae with a strong hood and fragile arista. Aricidea (Acmira) pseudoassimilis n. sp. is characterized by having a short, digitiform antenna; interramal lobes between notopodia and neuropodia; hook-shaped modified neurochaeta that gets subterminally thinner with a rounded tip. As A. (Strelzovia) bulbosa has been only previously reported from the Gulf of Suez (Red Sea), it could be a new alien species for the Sea of Marmara and Mediterranean Sea. Based on the characters that have been overlooked so far, the subspecies A. suecica meridionalis and A. capensis bansei were raised to species level, A. meridionalis n. stat. and A. bansei n. stat. The present paper reports the usage of ciliary bands and slits on the prostomium and body, swellings/ridges in the branchial region, and the shape and distribution of sense organs in the taxonomy of Aricidea. All species were described and figured.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Abesinghe A, Sudasinghe H, Amarasinghe A, et al (2020)

The identity of the exotic Pterygoplichthys sailfin catfishes in Sri Lanka (Teleostei: Loricariidae).

Zootaxa, 4852(1):zootaxa.4852.1.10 pii:zootaxa.4852.1.10.

Invasive alien species (IAS) are a major threat to biodiversity and have contributed to population declines in native species worldwide (Vilà et al. 2011; Gurevitch Padilla 2004). IUCN's Invasive Species Specialist Group lists some 80 invasive or potentially invasive species in Sri Lanka, which is part of a global biodiversity hotspot (Myers et al. 2000; Marambe et al. 2011). The major release of aquatic IAS on the island are routed through the ornamental-fish industry (Marambe et al. 2011; Sudasinghe 2016), though a minority represents deliberate, if unplanned, introductions by governmental and non-governmental agencies (Marambe et al. 2011).

RevDate: 2020-10-19
CmpDate: 2020-10-19

Smith RJ, CY Chang (2020)

Taxonomic assessments of some Cyprinotinae Bronstein, 1947 species (Crustacea: Ostracoda) from Japanese and Korean rice fields, including (re-) descriptions of six species and a review of the type species of the subfamily.

Zootaxa, 4795(1):zootaxa.4795.1.1 pii:zootaxa.4795.1.1.

Rice is the staple food crop for approximately half the world's population, but some common and abundant taxa inhabiting rice fields, such as ostracods, are poorly studied. For many ostracod species only brief, initial descriptions are available, hindering reliable identifications, and so their ecological roles in rice fields remain obscure. This study partially addresses this problem by assessing the taxonomic validity of six species of Cyprinotinae ostracods reported from rice fields in Japan and South Korea: Cyprinotus uenoi Brehm, 1936, Hemicypris megalops Sars, 1903, Hemicypris ovata Sars, 1903, Hemicypris vulgaris Okubo, 1990, Heterocypris rotundata (Bronstein, 1928), and Hemicypris kawagaensis Okubo, 2004 nomen nudum. Type material of C. uenoi was not designated and Brehm's ostracod collection is missing, but Japanese and Korean records of C. uenoi differ significantly from Brehm's original description. The Japanese and Korean species is described and named herein as Cyprinotus cassidula sp. nov. Japanese specimens reported to be Hemicypris megalops are probably misidentified, but details of the carapace of Hemicypris megalops are obscure due to poor preservation of type material. Examination of topotype material of Hemicypris posterotruncata Bate, 1970, a sub-fossil from near Lake Turkana in Kenya, demonstrates that this species is extant in Asian rice fields. Investigation of type material of Hemicypris kliei (Lindroth, 1953) has revealed that it is not a senior synonym of Hemicypris posterotruncata, contrary to previous studies. Size and morphological data indicates that Hemicypris vulgaris is a large form of Hemicypris posterotruncata and the two species are treated as synonyms herein. Examination of paralectotypes of Hemicypris ovata indicates that it is very similar to Hemicypris posterotruncata, especially the larger morphotypes, but as these two species can be distinguished by morphological features they are both retained as separate species. However, Japanese records of Hemicypris ovata are considered misidentifications of the larger forms of Hemicypris posterotruncata. Hemicypris kawagaensis, which has only been reported once from East Asia, is herein regarded as a junior synonym of Hemicypris barbadensis Broodbakker, 1983, and is likely an alien species in Asia. Asian specimens previously identified as Heterocypris rotundata show sufficient differences to European specimens to determine that they are not conspecific. This species is described as Heterocypris savatenalintonae sp. nov. Taxonomic descriptions of Hemicypris ovata, Hemicypris posterotruncata, Hemicypris megalops, Hemicypris kliei, Heterocypris savatenalintonae sp. nov., and Cyprinotus cassidula sp. nov. are presented. Finally, it is noted that past redescriptions of Cyprinotus cingalensis Brady, 1886, the type species of the genus and the subfamily Cyprinotinae Bronstein 1947, are based partly on other species.

RevDate: 2020-10-15

Leza M, NuÑez L, Riba JM, et al (2020)

First record of the black twig borer, Xylosandrus compactus (Coleoptera: Curculionidae, Scolytinae) in Spain.

Zootaxa, 4767(2):zootaxa.4767.2.9 pii:zootaxa.4767.2.9.

We present the first record for Spain of the black twig borer, Xylosandrus compactus, an ambrosia beetle of Asian origin, collected from an infested carob tree located in Calvià (Majorca, Balearic Islands, Spain). X. compactus is included in the EPPO Alert List, and it has been recently reported causing damages in a Mediterranean maquis ecosystem in Italy and Southern France. Here, we discuss about the first steps of management of this Invasive Alien species (IAS), the eradication plan and the hypothesis of the path of introduction in this Western Mediterranean island.

RevDate: 2020-10-19
CmpDate: 2020-10-19

Wilson GDF, CL Humphrey (2020)

The Eophreatoicus Nicholls, 1926 species flock from Kakadu and Arnhem Land, with a description of a new genus of Amphisopidae (Crustacea : Isopoda : Phreatoicidea).

Zootaxa, 4854(1):zootaxa.4854.1.1 pii:zootaxa.4854.1.1.

We present descriptions of 28 new species of Amphisopidae from Arnhem Land and Kakadu National Park of Australia's Northern Territory. We identified five additional species that are not yet fully characterized and are not provided with formal species recognition. This is the first taxonomic treatment highlighting the high species richness within the Phreatoicidea that occur in Australia and likely elsewhere. We document each species fully with scanning electron and light micrographic images, diagnoses, detailed descriptions, keys to identification and justification of each species using parsimony analysis of their morphological and genetic characters. The distributional data show that all species, except for one, have microendemic distributions, with some sibling species occurring within a few kilometers of each other. Because of the age of this group of species, they appear to have spread throughout the region of the Arnhem sandstone plateau and then back-colonized the same habitats so that as many as three morphologically and genetically distinct species may co-occur syntopically. Our research has uncovered a new genus-level taxon of the family Amphisopidae, Kakadubeh gen. nov. This new genus is unlike Eophreatoicus, not only in its general appearance, but also in having an inferred reproductive strategy different from most of the other members of the family. While Eophreatoicus species have males that are much larger than the females and practice precopula, a form of pre-insemination mate guarding, males of the new species, Kakadubeh rangemyahwurd sp. nov., are much smaller than females. In addition, males of this species have a fourth walking leg that is not specialized for holding females, suggesting that they have a reproductive strategy that does not involve precopula of the form seen in Eophreatoicus and Eremisopus Wilson Keable, 2002a. Most of our research has been undertaken in Kakadu National Park, although recent collections have been made in Arnhem Land, yielding additional distinctive species. Given the size of unexplored territory around the Arnhem Plateau and the geographic frequency of discovering new species, we predict that the diversity of this group in the Northern Territory may be many more than the ~35 species described here. At this time, these microendemic isopods appear to be unthreatened by human activities, largely owing to the environmental protection afforded by Kakadu National Park and Arnhem Land, and their cryptic habits during the dry season. Because they are dependent on small springs of permanent groundwater, future changes in hydrology owing to water use and climate change, as well as invasive introduced species, may present risks to populations and species.

RevDate: 2020-10-15

Carpinelli ÁN, Cordeiro RTS, Neves LM, et al (2020)

Erythropodium caribaeorum (Duchassaing and Michelotti, 1860) (Cnidaria: Alcyonacea), an additional alien coral in the Southwestern Atlantic.

Zootaxa, 4822(2):zootaxa.4822.2.2 pii:zootaxa.4822.2.2.

Invasive species may compromise biodiversity and ecosystem services, and represent a steadily growing concern for coastal marine ecosystems. The marine aquarium trade (MAT) is the source of some of the world's worst aquatic invasions, inflicting multimillion-dollar losses in infected regions. In the Southwestern Atlantic (SWA), two Indo-Pacific coral species were recently introduced as a result of the MAT and already dominate the substrate at the introduction site in Southeastern Brazil (Praia Vermelha, Angra dos Reis, Rio de Janeiro State). Herein, based on morphological and molecular evidence, we report a Caribbean native coral species likely introduced by the MAT in Praia Vermelha, Erythropodium caribaeorum (Duchassaing Michelotti 1860). While the eradication of coral species that already have a pest status in the SWA is unlikely, we propose that the eradication of the three species still contained to their introduction sites, including E. caribaeorum, is still feasible and depends on a rapid and integrated embracement of the task by core stakeholders. Priority actions for the regulation of MAT and hobbyism in Brazil are proposed.

RevDate: 2020-10-15

Grebennikov VV (2020)

Allaeotes niger, a weevil introduced to Cuba and the only known New World Stromboscerini (Coleoptera: Curculionidae: Dryophthorinae).

Zootaxa, 4803(3):zootaxa.4803.3.5 pii:zootaxa.4803.3.5.

Allaeotes niger He, Zhang and Pelsue, a weevil hitherto known only from the type series collected in China, is for the first time reported from Cuba. In addition to three historical Cuban specimens, approximately one hundred adults were observed in 2018 under bark of fallen logs at a plantation of (likely non-native) pines in westernmost Pinar del Río province. This is the only New World record of a member of the monophyletic core of the tribe Stromboscerini, otherwise distributed in a triangle delimited by Japan, Sri Lanka and northern Australia (plus a single mysterious record from Uganda). Phylogenetic analysis of one mitochondrial (COI) and two nuclear (ITS2 and 28S) markers recovered the Cuban specimens nested within the tribe, but not in a clade with two unnamed congeners from Vietnam. Adults of all four known Allaeotes species are illustrated, including both named ones. Remarkably, both Cuban and Ugandan records of extraterritorial Stromboscerini pertain to species associated with dead wood, a biological trait possibly facilitating human-assisted transoceanic dispersal. Cuban populations of A. niger are interpreted as a pre-1990 human-mediated introduction. Two additional specimens of A. niger intercepted at US ports of entry arriving from China and the Dominican Republic, respectively, corroborate this hypothesis and suggest China as a likely origin of the Cuban introduction. All data used herein (specimen images, geographical localities, DNA sequences) are available online in a public dataset dx.doi.org/10.5883/DS-VGDS012.

RevDate: 2020-10-15

Roberts DM, Boag B, Hunter F, et al (2020)

Genetic variability of Arthurdendyus triangulatus (Dendy, 1894), a non-native invasive land planarian.

Zootaxa, 4808(1):zootaxa.4808.1.2 pii:zootaxa.4808.1.2.

Arthurdendyus triangulatus (Dendy, 1894) is a land planarian native to New Zealand which has become established in the United Kingdom and the Faroe Islands during the last 60 years. The species has become prevalent and widely established in Scotland mediated by human activity mostly through the exchange of plants and associated soil. As a predator of earthworms, concerns regarding both the direct impact on earthworm abundance and diversity and the indirect impact on those birds and mammals that have earthworms as a primary dietary component led to A. triangulatus being the subject of both national and EU regulation. Whilst much is known regarding the ecology of A. triangulatus there is a significant knowledge gap regarding the genetic variability of the species. Using four DNA target regions cytochrome oxidase (CoI), elongation factor (EF), internal transcribed spacer region (ITS-1) and large subunit (LSU), we characterised the genetic variability of A. triangulatus populations across its full geographic range in Scotland and included a few populations from New Zealand, England and Northern Ireland. Two DNA regions, ITS-1 and CoI, revealed inter-population variability yielding well supported genetic structure in predominantly Scottish populations. We also identified considerable intra-specific and intra-individual heterogeneity in both ribosomal and mitochondrial regions, including the prevalence of pseudo-gene nuclear encoded mitochondrial DNA (Numt), the latter not previously reported for Platyhelminthes. Furthermore, given the presence of multiple ITS-1 haplotypes in individual specimens of A. triangulatus it is not possible to make definitive comment to support previously published findings that A. triangulatus was subjected to multiple introductions into the UK.

RevDate: 2020-10-15

Bernard J, CPDT Gillett (2020)

A new species of cylindrical bark beetle (Zopheridae: Colydiinae) from Vanuatu establishes in Hawaii.

Zootaxa, 4809(3):zootaxa.4809.3.12 pii:zootaxa.4809.3.12.

We describe Bulasconotus scaccarius sp. nov., a new species of cylindrical bark beetle (Zopheridae: Colydiinae: Synchitini), elevating the number of described species in its genus to two. Despite discovering this species in Hawaii, we suspect, based on collections and survey data, that it is endemic to the South Pacific archipelago of Vanuatu and has only recently arrived in Hawaii. Evidence of the diet of closely related genera indicates that the new species may be a predator of ambrosia beetles (Curculionidae: Scolytinae), conceivably posing a risk to those that are endemic to Hawaii.

RevDate: 2020-10-15

Nardi G, Bocci M, R Poggi (2020)

Ptilodactyla exotica Chapin, 1927 in Italy (Coleoptera: Ptilodactylidae).

Zootaxa, 4861(1):zootaxa.4861.1.4 pii:zootaxa.4861.1.4.

Ptilodactyla exotica Chapin, 1927 is a subcosmopolitan synanthropic species introduced to Europe with tropical ornamental plants. It is here firstly recorded from central Italy (Tuscany region), and its Italian chronogeonemy (1940-2016) is summarized. Most records come from the Genoa province (Northern Italy, Liguria region), where this species was repeatedly collected in the period 1940-1999.

RevDate: 2020-10-15

Mutlu E, ÇaĞatay IT, Olguner MT, et al (2020)

A new sea-nettle from the Eastern Mediterranean Sea: Chrysaora pseudoocellata sp. nov. (Scyphozoa: Pelagiidae).

Zootaxa, 4790(2):zootaxa.4790.2.2 pii:zootaxa.4790.2.2.

A new species of Chrysaora is described from five specimens collected off Turkey in the Eastern Mediterranean Sea during December 2018. The species is characterised by its pale exumbrella, milky to creamy in colour, bearing faint and narrow markings, strap-like marginal tentacles, semi-rounded to tongue-shaped lappets, and a prominent dark spot on the exumbrella above each rhopalium. Analysis of the COI gene indicates that it may be most closely related to Chrysaora africana (Vanhöffen 1902), from which it is nevertheless 10.2 % different. It is unclear whether the species represents a previously undetected and endemic species from the Mediterranean, or whether source populations are located in the Red Sea and the northern Indian Ocean.

RevDate: 2020-10-15

Joshi S, Pai SG, Deepthy KB, et al (2020)

The cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Coccomorpha: Pseudococcidae) arrives in India.

Zootaxa, 4772(1):zootaxa.4772.1.8 pii:zootaxa.4772.1.8.

Invasive species threaten the ecological and economic wellbeing of a country (Pimentel et al. 2001). In the last decade, several mealybugs and soft scale insects have been accidentally introduced to India, of which some have become serious pests (e.g., Phenacoccus solenopsis Tinsley, Paracoccus marginatus Williams Granara de Willink, Phenacoccus madeirensis Green and Pseudococcus jackbeardsleyi Gimpel Miller); others are widening their host ranges and spreading rapidly. Kilifia acuminata (Signoret) and Protopulvinaria longivalvata Green seem relatively harmless but Trijuba oculata (Brain) and Pulvinaria urbicola Cockerell cause economic damage (Joshi Rameshkumar 2013; Joshi 2017).

RevDate: 2020-10-15

Lee CC, Lin CY, Tseng SP, et al (2020)

Ongoing Coevolution of Wolbachia and a Widespread Invasive Ant, Anoplolepis gracilipes.

Microorganisms, 8(10): pii:microorganisms8101569.

While Wolbachia are commonly found among arthropods, intraspecific infection rates can vary substantially across the geographic populations. Here we report nearly 100% prevalence of Wolbachia in the global populations of the yellow crazy ant, Anoplolepis gracilipes. To understand coevolutionary history between Wolbachia and A. gracilipes, we identified single nucleotide polymorphisms (SNPs) in Wolbachia from the ant across 12 geographical regions and compared the phylogeny of SNP-based Wolbachia to patterns of the ant's mitochondrial DNA (mtDNA) variation. Our results revealed a strong concordance between phylogenies of Wolbachia and host mtDNA, providing immediate evidence of co-divergence. Among eight identified SNP loci separating the genetic clusters of Wolbachia, seven loci are located in potential protein-coding genes, three of which being non-synonymous SNPs that may influence gene functions. We found a Wolbachia hypothetical protein gene with signature of positive selection. These findings jointly allow us to characterize Wolbachia-ant coevolution and also raise a question about mechanism(s) underlying maintenance of high prevalence of Wolbachia during the colonization of this invasive ant.

RevDate: 2020-10-15

Wu YH, Kamiyama MT, Chung CC, et al (2020)

Population Monitoring, Egg Parasitoids, and Genetic Structure of the Invasive Litchi Stink Bug, Tessaratoma papillosa in Taiwan.

Insects, 11(10): pii:insects11100690.

Here we assessed population dynamics, natural enemy fauna (with emphasis on egg parasitoid), and population genetic structure (based on mitochondrial DNA) of the invasive litchi stink bug (LSB), Tessaratoma papillosa in Taiwan. Our major findings include: (1) fluctuations of LSB in numbers of adults, mating pairs, and egg masses over a 2-year period in Taiwan generally resemble those in the native populations; (2) Anastatusdexingensis and A. fulloi are among the most dominant LSB egg parasitoids, with the former consistently outnumbering the latter throughout Taiwan; (3) the presence of two genetically distinct clades suggests LSB in Taiwan most likely derived from multiple invasions. All these data practically improve our understanding of this invasive insect pest, particularly its ecological and genetic characteristics in the introduced area, which represents critical baseline information for the design of future integrated pest management strategies.

RevDate: 2020-10-14

Ryan LM, AR Gunderson (2020)

Competing native and invasive Anolis lizards exhibit thermal preference plasticity in opposite directions.

Journal of experimental zoology. Part A, Ecological and integrative physiology [Epub ahead of print].

Invasive species have emerged as a significant problem in the age of anthropogenic change. Behavior can be key to invasive species success and is strongly affected by temperature. Therefore, knowledge of the temperature dependence of behavior is likely critical to understand invasive species dynamics and their interactions with native species. In this study, we tested for differences in thermal preference plasticity and temperature-dependent activity levels in a pair of congeneric lizards found in the United States: the invasive Anolis sagrei and the native A. carolinensis. We predicted that A. sagrei would demonstrate greater thermal preference plasticity and would utilize a higher and/or wider range of activity temperatures than A. carolinensis. Both would point to plasticity allowing A. sagrei to behaviorally exploiting thermal conditions that A. carolinensis cannot. We found that both species exhibited plasticity in thermal preference, but in opposite directions: preferred temperatures of A. carolinensis increased with acclimation temperature, while those of A. sagrei decreased. As a result, which species had a higher thermal preference changed with acclimation conditions. We saw no difference in overall field activity rates between the species, but that A. sagrei did tend to be active over a broader range of body temperatures. In sum, we found little evidence that differences in thermal preference plasticity between the species allow A. sagrei to remain active at a higher or broader temperature range than A. carolinensis. Nonetheless, the thermal preference data suggest complementary thermal preferences between the species that could promote microclimatic partitioning, though more work is required to test this idea.

RevDate: 2020-10-14

Ruttanaphan T, de Sousa G, Pengsook A, et al (2020)

A Novel Insecticidal Molecule Extracted from Alpinia galanga with Potential to Control the Pest Insect Spodoptera frugiperda.

Insects, 11(10): pii:insects11100686.

Spodoptera frugiperda, a highly polyphagous insect pest from America, has recently invaded and widely spread throughout Africa and Asia. Effective and environmentally safe tools are needed for successful pest management of this invasive species. Natural molecules extracted from plants offer this possibility. Our study aimed to determine the insecticidal efficacy of a new molecule extracted from Alpinia galanga rhizome, the 1'S-1'-acetoxychavicol acetate (ACA). The toxicity of ACA was assessed by topical application on early third-instar larvae of S. frugiperda. Results showed that ACA caused significant larval growth inhibition and larval developmental abnormalities. In order to further explore the effects of this molecule, experiments have been performed at the cellular level using Sf9 model cells. ACA exhibited higher toxicity on Sf9 cells as compared to azadirachtin and was 38-fold less toxic on HepG2 cells. Inhibition of cell proliferation was observed at sublethal concentrations of ACA and was associated with cellular morphological changes and nuclear condensation. In addition, ACA induced caspase-3 activity. RT-qPCR experiments reveal that ACA induces the expression of several caspase genes. This first study on the effects of ACA on S. frugiperda larvae and cells provides evidence that ACA may have potential as a botanical insecticide for the control of S. frugiperda.

RevDate: 2020-10-15

Yuan M, JR Stinchcombe (2020)

Population genomics of parallel adaptation.

Parallel evolution is one of the striking patterns in nature. The presence of repeated evolution of the same phenotypes, suites of traits, and adaptations suggests a strong role for natural selection in shaping biological diversity. The reasoning is straightforward: each instance of repeated evolution makes it less likely that these features evolved neutrally or due to stochastic forces in each population or species. With the growing sequencing capability, we are now poised to examine the genetic basis of parallel evolution in model and nonmodel systems. On pages X-Y of this issue of Molecular Ecology, van Boheemen and Hodgins (2020) provide an exemplar study of this kind, using common ragweed (Ambrosia artemisiifolia; Figure 1a). Their study is noteworthy and ambitious in many respects, and we think will serve as a model for studying parallel adaptation, even in nonmodel species.

RevDate: 2020-10-15
CmpDate: 2020-10-15

Bhuyain MMH, UT Lim (2020)

Relative susceptibility to pesticides and environmental conditions of Frankliniella intonsa and F. occidentalis (Thysanoptera: Thripidae), an underlying reason for their asymmetrical occurrence.

PloS one, 15(8):e0237876.

To explain the asymmetrical abundance of native Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) and invasive Frankliniella occidentalis (Pergande) in the fields, we examined differential susceptibility to pesticides and environmental conditions, i.e., nine combinations of temperatures and relative humidities (RHs). We found adult female F. intonsa to be more susceptible to most of the tested insecticides as compared to F. occidentalis. Chlorfenapyr was most toxic to both thrips' species. In the evaluation of environment conditions in the adult stage, F. intonsa survived 2.5 and 2.4-fold longer as RH increased at 20 and 25 °C, respectively, whereas F. occidentalis survived 1.8 and 1.6-fold longer, respectively. In both pupal and larval stage, no significant effect of interaction of temperatures and RHs was found between the two species. In conclusion, the insecticides tested differed considerably in their species-specific toxicity, and F. intonsa was generally more susceptible to the insecticides, while at the same time survivorship was better at higher RH conditions than F. occidentalis. Thus, differences in the relative susceptibility to changing environmental conditions, especially humidity, may be an underlying mechanism for the recent dominance of F. intonsa over F. occidentalis in the strawberry plastic greenhouse in Korea.

RevDate: 2020-10-14
CmpDate: 2020-10-14

Werner SJ, Fischer JW, KA Hobson (2020)

Multi-isotopic (δ2H, δ13C, δ15N) tracing of molt origin for European starlings associated with U.S. dairies and feedlots.

PloS one, 15(8):e0237137.

Introduced bird species can become invasive in agroecosystems and their management is inhibited if their origin and movements are not well understood. Stable isotope measurements of feathers can be used to infer molt origins and interstate movements in North America. We analyzed stable-hydrogen (δ2H), carbon (δ13C) and nitrogen (δ 15N) isotope ratios in feathers to better understand the molt origin of European starlings (Sturnus vulgaris) collected at dairies and feedlots throughout the United States. Primary feathers were used from 596 adult and 90 juvenile starlings collected during winter at dairies and feedlots that experience starling damages in Arizona, California, Colorado, Idaho, Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, Oregon, Texas, Vermont, Washington and Wisconsin. The best-fit model indicated that the combination of feather δ2H, δ13C and δ15N values best predicted the state where samples were collected and thus supported use of this approach for tracing molt origins in European starlings. Interestingly, molt origins of starlings collected at dairies and feedlots generally west of -90° longitude (i.e. 11 of 15 states west of the Mississippi River, including Wisconsin) were assigned to the collection state and/or the state adjacent to the collection state. In contrast, molt origins of starlings collected generally east of -90° longitude (four of five eastern states) were not assigned to the collection state and/or the state adjacent to the collection state. Among all starlings (N = 686), 23% were assigned to the collection state and 19% were assigned to the state adjacent to the collection state. Among all males (N = 489) and all females (N = 197), 23% and 26% were assigned to the collection state and 19% and 13% were assigned to the state adjacent to the collection state, respectively. We observed a greater proportion (88%) of juvenile starlings assigned to states other than their collection state (i.e. potentially a result of natal dispersal) than that proportion (76%) in adult starlings. This study included an unprecedented sample of feather isotopes from European starlings throughout the United States. As a novel contribution to the ecology and management of invasive and migratory passerines, we demonstrate how such feather isoscapes can be used to predict molt origin and, potentially, interstate movements of European starlings for subsequent ecological and management investigations.

RevDate: 2020-10-14
CmpDate: 2020-10-14

Lamelas-López L, Pardavila X, Borges PAV, et al (2020)

Modelling the distribution of Mustela nivalis and M. putorius in the Azores archipelago based on native and introduced ranges.

PloS one, 15(8):e0237216.

The aims of this study were to predict the potential distribution of two introduced Mustelidae, Mustela nivalis and M. putorius in the Azores archipelago (Portugal), and evaluate the relative contribution of environmental factors from native and introduced ranges to predict species distribution ranges in oceanic islands. We developed two sets of Species Distribution Models using MaxEnt and distribution data from the native and introduced ranges of the species to project their potential distribution in the archipelago. We found differences in the predicted distributions for the models based on introduced and on native occurrences for both species, with different most important variables being selected. Climatic variables were most important for the introduced range models, while other groups of variables (i.e., human-disturbance) were included in the native-based models. Most of the islands of the Azorean archipelago were predicted to have suitable habitat for both species, even when not yet occupied. Our results showed that predicting the invaded range based on introduced range environmental conditions predicted a narrower range. These results highlight the difficulty to transfer models from native to introduced ranges across taxonomically related species, making it difficult to predict future invasions and range expansion.

RevDate: 2020-10-14
CmpDate: 2020-10-14

Santolamazza-Carbone S, Durán-Otero M, M Calviño-Cancela (2019)

Context dependency, co-introductions, novel mutualisms, and host shifts shaped the ectomycorrhizal fungal communities of the alien tree Eucalyptus globulus.

Scientific reports, 9(1):7121 pii:10.1038/s41598-019-42550-x.

The identity and relevance of the ectomycorrhizal (ECM) fungal partners of Eucalyptus globulus was investigated in NW Spain, to detect which symbionts mainly support its invasiveness. Root tips of E. globulus and of three common native plant species (Quercus robur, Pinus pinaster and Halimium lasianthum) were collected in eucalypt plantations, Q. robur forests, P. pinaster plantations and shrublands. Fungal taxonomical identity was ascertained by use of rDNA and direct sequencing. We studied diversity, composition and colonization rate of the ECM fungal communities of E. globulus to determine if fungal assemblages are host specific (i.e. similar in different habitats) or more dependent on the neighbourhood context. We also identified the type of associations formed (i.e. co-introductions, familiar or novel associations). Twenty-six ECM taxa were associated with E. globulus. Most of them engaged in novel associations with eucalypts, whereas only three fungal species were co-introduced Australian aliens. Eucalypt fungal richness, diversity and colonization rate differed between habitats, being higher in native oak forests, whereas in shrublands E. globulus showed the lowest colonization rate and diversity. The Australian fungus Descolea maculata dominated the eucalypt fungal assemblage and also spread to the native host plants, in all the habitats, posing the risk of further co-invasion.

RevDate: 2020-10-16
CmpDate: 2020-10-16

Arthur FH, Morrison WR, AC Morey (2019)

Modeling the potential range expansion of larger grain borer, Prostephanus truncatus (Coleoptera: Bostrichidae).

Scientific reports, 9(1):6862 pii:10.1038/s41598-019-42974-5.

Prostephanus truncatus (Horn) (Coleoptera: Bostrichidae), is a beetle that is a member of a family that is primarily comprised of wood-boring insects, including forest insect pests. It is native to Mexico and Central America, where it has adapted to become a pest of stored maize. It was accidentally introduced into Africa in late 1970s, where it quickly spread throughout the sub-Saharan region, perhaps aided by adaptation to alternate hosts and the ability to persist in non-agricultural habitats. We used the correlative modelling algorithm, MaxEnt, to identify global areas of potential high suitability based on the climate locations with documented populations. Predictions using a model trained in Mexico + Central America showed potential high climatic suitability extending north into the southern United States and southward into South America, including parts of Argentina, but predictions using a model built from African occurrences did not include those areas as highly suitable. However, there was general agreement in both models that large areas of the tropics in the Western Hemisphere and in Asia have climatic conditions that could support P. truncatus if it were to become established. The models also showed consistency in capturing potential suitability at sites not used to build a given model. Results can be used as an initial guide to establish surveillance programs to monitor for this insect in high risk areas where it is not currently found, and to proactively mitigate the biosecurity risk from P. truncatus.

RevDate: 2020-10-13

Balzani P, Haubrock PJ, Russo F, et al (2020)

Combining metal and stable isotope analyses to disentangle contaminant transfer in a freshwater community dominated by alien species.

Environmental pollution (Barking, Essex : 1987), 268(Pt B):115781 pii:S0269-7491(20)36470-8 [Epub ahead of print].

Freshwater ecosystems are negatively impacted by various pollutants, from agricultural, urban and industrial wastewater, with metals being one of the largest concerns. Moreover, freshwater ecosystems are often affected by alien species introductions that can modify habitats and trophic relationships. Accordingly, the threat posed by metals interacts with those by alien species, since the latter can accumulate and transfer these substances across the food web to higher trophic levels. How metals transfer within such communities is little studied. We analysed the concentration of 14 metals/metalloids (Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, Pb, Se, Zn, hereafter 'metal(s)') of eight fish and three crustacean species co-existing in the Arno River (Central Italy), most of which were alien. To assess the pathway of contaminants within the community, we coupled metal analysis with carbon and nitrogen stable isotope analysis derived from the same specimens. Crustaceans showed higher metal concentration than fish, except for Cd, Hg and Se that were higher in fish. We found evidence of trophic transfer for six metals (Cd, Cr, Hg, Mg, Se, Zn). Additionally, ontogenetic differences and differences among various fish tissues (muscle, liver, and gills) were found in metals concentration. Considerable biomagnification along the trophic chain was found for Hg, while other metals were found to biodilute. Using stable isotopes and Hg as a third diet tracer, we refined the estimations of consumed preys in the diet previously reconstructed with stable isotope mixing models. Alien species reach high biomass and can both survive to and accumulate high pollutants concentrations, potentially posing a risk for their predators and humans. A combined effect of environmental filtering and increased competition may potentially contribute to the disappearance of native species with lower tolerances.

RevDate: 2020-10-13

Vandermeer J, I Perfecto (2020)

Endogenous spatial pattern formation from two intersecting ecological mechanisms: the dynamic coexistence of two noxious invasive ant species in Puerto Rico.

Proceedings. Biological sciences, 287(1936):20202214.

Endogenous (or autonomous, or emergent) spatial pattern formation is a subject transcending a variety of sciences. In ecology, there is growing interest in how spatial patterns can 'emerge' from internal system processes and simultaneously affect those very processes. A classic situation emerges when a predator's focus on a dominant competitor releases competitive pressure on a subdominant competitor, allowing coexistence of the two. If this idea is formulated spatially, two interesting consequences immediately arise. First, a spatial predator/prey system may take the form of a Turing instability, in which an activator (the dispersing prey population) is contained by a repressor (the more rapidly dispersing predator population) generating a spatial pattern of clusters of prey and predators, and second, an indirect intransitive loop (where A beats B beats C beats A) emerges from the simple fact that the system is spatial. Two common invasive ant species, Wasmannia auropunctata and Solenopsis invicta, and the parasitic phorid flies of S. invicta commonly coexist in Puerto Rico. Emergent spatial patterns generated by the combination of the Turing mechanism and the indirect intransitive loop are likely to be common here. This theoretical framework and the realities of the natural history in the field could explain both the long-term coexistence of these two species, and the highly variable pattern of their occurrence across a large landscape.

RevDate: 2020-10-13

Sharp SJ, Elgersma KJ, Martina JP, et al (2020)

Hydrologic flushing rates drive nitrogen cycling and plant invasion in a freshwater coastal wetland model.

Ecological applications : a publication of the Ecological Society of America [Epub ahead of print].

Coastal wetlands intercept significant amounts of nitrogen (N) from watersheds, especially when surrounding land cover is dominated by agriculture and urban development. Through plant uptake, soil immobilization, and denitrification wetlands can remove excess N from flow through water sources and mitigate eutrophication of connected aquatic ecosystems. Excess N can also change plant community composition in wetlands, including communities threatened by invasive species. Understanding how variable hydrology and N loading impact wetland N removal and community composition can help attain desired management outcomes, including optimizing N removal and/or preventing invasion by non-natives. By using a dynamic, process-based ecosystem simulation model, we are able to simulate various levels of hydrology and N loading that would otherwise be difficult to manipulate. We investigate in silico the effects of hydroperiod, hydrologic residence time, N loading, and the NH4+ :NO3- ratio on both N removal and the invasion success of two non-native species (Typha x glauca or Phragmites australis) in temperate freshwater coastal wetlands. We found that when residence time increased, annual N removal increased up to 10-fold while longer hydroperiods also increased N removal, but only when residence time was >10 days and N loading was >30 g N m-2 y-1 . N removal efficiency also increased with increasing residence time and hydroperiod, but was less affected by N loading. However, longer hydrologic residence time increased vulnerability of wetlands to invasion by both invasive plants at low to medium N loading rates where native communities are typically more resistant to invasion. This suggests a potential tradeoff between ecosystem services related to nitrogen removal and wetland invasibility. These results help elucidate complex interactions of community composition, N loading and hydrology on N removal, helping managers to prioritize N removal when N loading is high or controlling plant invasion in more vulnerable wetlands.

RevDate: 2020-10-13

Keller JA, K Shea (2020)

Warming and shifting phenology accelerate an invasive plant life cycle.

Ecology [Epub ahead of print].

Numerous studies have documented changes in the seasonal timing of organisms' growth and reproduction in response to climate warming. These changes correlate with documented changes in species' abundance, but mechanisms linking these trends remain elusive. We investigated the joint demographic effects of advanced reproductive phenology and warming on a globally invasive plant (Carduus nutans) in a field experiment, documenting a substantial shift toward completion of the life cycle at younger ages. Demographic modeling projected 71% of warmed individuals flower as annuals, compared to 61% under current conditions. As this species only reproduces once, this represents a major acceleration of the life cycle. We project a 15% increase in this invader's population growth rate. We show that rising temperatures accelerate this invasive species' population growth by increasing the average size of reproducing individuals; increasing the proportion of individuals that survive to reproduce; and increasing the fraction that reproduce as annuals. Major increases in population growth in this, and potentially many other, invasive species will threaten food security and require careful planning to avoid significant environmental and economic impacts.

RevDate: 2020-10-13

Posavi M, Gulisija D, Munro JB, et al (2020)

Rapid evolution of genome-wide gene expression and plasticity during saline to freshwater invasions by the copepod Eurytemora affinis species complex.

Molecular ecology [Epub ahead of print].

Saline migrants into freshwater habitats constitute among the most destructive invaders in aquatic ecosystems throughout the globe. However, evolutionary and physiological mechanisms underlying such habitat transitions remain poorly understood. To explore mechanisms of freshwater adaptation and distinguish between adaptive (evolutionary) and acclimatory (plastic) responses to salinity change, we examined genome-wide patterns of gene expression between ancestral saline and derived freshwater populations of the Eurytemora affinis species complex, reared under two different common-garden conditions (0 vs. 15 PSU). We found that evolutionary shifts in gene expression (between saline and freshwater inbred lines) showed far greater changes and were more widespread than acclimatory responses to salinity (0 vs. 15 PSU). Most notably, 30-40 genes showing evolutionary shifts in gene expression across the salinity boundary were associated with ion transport function, with inorganic cation transmembrane transport forming the largest Gene Ontology category. Of particular interest was the sodium transporter, the Na+ /H+ antiporter (NHA) gene family, which was discovered in animals relatively recently. Thirty key ion regulatory genes, such as NHA paralog #7, demonstrated concordant evolutionary and plastic shifts in gene expression, suggesting the evolution of ion transporter function and plasticity during rapid invasions into novel salinities. Moreover, freshwater invasions were associated with the evolution of reduced plasticity in the freshwater population, again for the same key ion transporters, consistent with the predicted evolution of canalization following adaptation to stressful conditions. Our results have important implications for understanding evolutionary and physiological mechanisms of range expansions by some of the most widespread invaders in aquatic habitats.

RevDate: 2020-10-13

McCorquodale-Bauer K, N Cicek (2020)

Zebra Mussel Shells as an Alternative Mineral Resource for Lime Production as a Phosphorus Precipitant.

Environmental technology [Epub ahead of print].

Zebra mussels are an invasive species to North America and are presently found in many rivers and lakes in prolific numbers. Along with many other issues, zebra mussels present a problem when their shells are deposited on shore, carpeting beaches and reducing beach usability. A possible solution presented in this study is to use the zebra mussel shells as an alternative mineral resource to mined calcium carbonate for the production of lime to remove phosphorus in wastewater. Heat-treated coarse (500 μm-1000 μm) and fine (< 75 μm) zebra mussel shell dosed to 10 mg L-1 phosphate solution at 0.50 g L-1 and 0.25 g L-1, removed over 99% phosphorus while maintaining pH levels significantly lower than pure calcium hydroxide dosed under the same conditions. It was found that ground zebra mussel shells (< 75 μm) heated for 1 hour at temperatures of 600, 700, 800, 900, and 1000 oC were capable of removing varying levels of phosphorus in water. Shells heated at 800 oC and dosed at 1.00 g L-1 reduced phosphorus in collected real wastewater effluent by 99.48%. It was also shown that shells heat treated at 1000 oC achieved 98.7% phosphorus removal when dosed at 0.25 g L-1, while maintaining a final effluent pH of 9.13, demonstrating the lowest overall energy costs of any of the effective shell treatments. The results indicate that zebra mussel shells show promise as an alternative resource for phosphorus precipitation in wastewater.

RevDate: 2020-10-12

Khan MA, Wani GA, Majid H, et al (2020)

Differential Bioaccumulation of Select Heavy Metals from Wastewater by Lemna minor.

Bulletin of environmental contamination and toxicology pii:10.1007/s00128-020-03016-3 [Epub ahead of print].

The capacity of Lemna minor to remediate toxic heavy metals from wastewater is reasonably well documented. In view of the pivotal role of this species in the environmental clean-up, here we evaluated the bioaccumulation potential of L. minor for cadmium (Cd), lead (Pb), and nickel (Ni) through a controlled experiment. L. minor tolerated the metals Cd, Ni, and Pb up to 0.5, 5, and 8 mg/L, respectively, and beyond these concentrations the toxicity symptoms appeared. Bio-concentration factor varied at different concentrations of heavy metals tested. Overall, L. minor showed good phytoremediation potential for all the three tested heavy metals (Cd, Ni, and Pb), though in relative terms it was more effective in extracting Ni and Cd, as compared to Pb, both in single and mixed concentrations. In view of the growing pollution in Kashmir Himalayan aquatic habitats the phytoremediation by invasive species such as L. minor promises to be one of the best choices than other native plants for cleaning up of polluted soils/water because of its fast growth rate, high abundance, easy handling, and wide distribution in Kashmir Himalayan aquatic ecosystems.

RevDate: 2020-10-11

Ha MK, Schneider SA, LS Adler (2020)

Facilitative pollinator sharing decreases with floral similarity in multiple systems.

Oecologia pii:10.1007/s00442-020-04770-1 [Epub ahead of print].

Investigating the factors that determine whether interactions are competitive or facilitative is essential to understanding community structure and trait evolution. Co-flowering plants interact indirectly through shared pollinators, and meta-analyses suggest that phylogenetic relatedness and floral trait similarity may predict the outcome of these interactions. In a comparative approach, we manipulated the floral community across five focal species to assess how floral similarity and phylogenetic relatedness affect the outcome of interactions. To assess the extent of pollinator-mediated competition versus facilitation, we compared pollen limitation in five focal species growing with floral neighbors (either congeners or neighbors from a different family) relative to a control (growing alone). We measured floral morphology, color, and nectar traits to calculate multivariate floral similarity between species pairs and inferred a phylogeny to calculate phylogenetic distance. Pollinator-mediated interaction values were regressed against floral similarity and phylogenetic distance. We found evidence of pollinator-mediated facilitation in nine of 13 species pairs. Furthermore, floral similarity and phylogenetic distance reduced facilitative interactions, but the latter relationship was not significant when controlling for the identity of the focal species. Our results suggest that facilitative pollinator sharing is more common than reported in the literature, but co-flowering plant species with similar floral traits are less likely to facilitate pollination. A better understanding of the factors that promote facilitation versus competition has important potential applications for managing rare and invasive species.

RevDate: 2020-10-10

Tylan C, Horvat-Gordon M, Bartell PA, et al (2020)

Ecoimmune reallocation in a native lizard in response to the presence of invasive, venomous fire ants in their shared environment.

Journal of experimental zoology. Part A, Ecological and integrative physiology [Epub ahead of print].

Exposure to stressors over prolonged periods can have fitness-relevant consequences, including suppression of immune function. We tested for effects of presence of an invasive species threat on a broad panel of immune functions of a coexisting lizard. Eastern fence lizards (Sceloporus undulatus) have been exposed to invasive fire ants (Solenopsis invicta) for over 80 years. Fire ants sting and envenomate lizards, causing physiological stress, but we do not have a comprehensive understanding of the broad immune consequences of lizard exposure to fire ant presence. We conducted a suite of immune measures on fence lizards caught from areas with long histories of fire ant invasion and lizards from areas not yet invaded by fire ants. The effect of fire ant presence on immunity varied depending on the immune component measured: within fire ant invaded areas, some portions of immunity were suppressed (lymphocytic cell-mediated immunity, complement), some were unaffected (phagocytic respiratory burst, natural antibodies), and some were enhanced (anti-fire ant immunoglobulin M, basophils) compared to within uninvaded areas. Rather than fire ants being broadly immunosuppressing, as generally assumed, the immune response appears to be tailored to this specific stressor: the immune measures that were enhanced are important to the lizards' ability to handle envenomation, whereas those that were unaffected or suppressed are less critical to surviving fire ant encounters. Several immune measures were suppressed in reproductive females when actively producing follicles, which may make them more susceptible to immunosuppressive costs of stressors such as interactions with fire ants.

RevDate: 2020-10-10

Mamantov MA, KS Sheldon (2020)

Behavioural responses to warming differentially impact survival in introduced and native dung beetles.

The Journal of animal ecology [Epub ahead of print].

BACKGROUND: Anthropogenic changes are often studied in isolation but may interact to affect biodiversity. For example, climate change could exacerbate the impacts of biological invasions if climate change differentially affects invasive and native species. Behavioural plasticity may mitigate some of the impacts of climate change, but species vary in their degree of behavioural plasticity. In particular, invasive species may have greater behavioural plasticity than native species since plasticity helps invasive species establish and spread in new environments. This plasticity could make invasives better able to cope with climate change.

GOAL: Here our goal was to examine whether reproductive behaviours and behavioural plasticity vary between an introduced and a native Onthophagus dung beetle species in response to warming temperatures and how differences in behaviour influence offspring survival.

METHODS: Using a repeated measures design, we exposed small colonies of introduced O. taurus and native O. hecate to three temperature treatments, including a control, low warming, and high warming treatment, and then measured reproductive behaviours, including the number, size, and burial depth of brood balls. We reared offspring in their brood balls in developmental temperatures that matched those of the brood ball burial depth to quantify survival.

RESULTS: We found that the introduced O. taurus produced more brood balls and larger brood balls, and buried brood balls deeper than the native O. hecate in all treatments. However, the two species did not vary in the degree of behavioural plasticity in response to warming. Differences in reproductive behaviours did affect survival, such that warming temperatures had a greater effect on survival of offspring of native O. hecate compared to introduced O. taurus.

BROADER IMPLICATIONS: Overall, our results suggest that differences in behaviour between native and introduced species is one mechanism through which climate change may exacerbate negative impacts of biological invasions.

RevDate: 2020-10-12

Uyi OO (2020)

Light environments affect herbivory patterns but not reproductive performance of a multivoltine specialist moth, Pareuchaetes pseudoinsulata.

Scientific reports, 10(1):16868 pii:10.1038/s41598-020-74079-9.

Unravelling the responses of insect herbivores to light-environment-mediated variation in the traits of their host plants is central to our understanding of the nutritional ecology of, and factors driving the population dynamics in, these species. This study examined the effect of light environment (shaded vs full-sun habitat) on leaf toughness and leaf nutritional quality in Chromolaena odorata (an invasive species in West Africa) and related these attributes to the abundance, herbivory patterns and reproductive performance of a multivoltine specialist moth, Pareuchaetes pseudoinsulata (a biological control agent). In this system, plants growing in shaded areas in the field experienced more herbivory and had higher herbivore abundance than those growing in full-sun. In the laboratory, P. pseudoinsulata larvae consumed significantly greater amounts of shaded foliage relative to full-sun foliage. However, reproductive performance metrics such as mating success, pre-oviposition period, number of eggs laid, duration of egg laying, egg hatchability, and adult longevity in P. pseudoinsulata did not differ according to foliage types. Reduced leaf toughness, increased water and nitrogen contents in shaded leaves coincided with increased leaf consumption by the larvae of P. pseudoinsulata. In summary, this study showed for the first time that light environments affect herbivory patterns but not reproductive performance of P. pseudoinsulata and hypothesized that high foliar nitrogen and water contents in shaded leaves resulted in feedback and necessity consumption patterns.

RevDate: 2020-10-12

Griffen BD, Bailey J, Carver J, et al (2020)

Mechanisms of possible self-limitation in the invasive Asian shore crab Hemigrapsus sanguineus.

Scientific reports, 10(1):16908 pii:10.1038/s41598-020-74053-5.

Population sizes of invasive species are commonly characterized by boom-bust dynamics, and self-limitation via resource depletion is posited as one factor leading to these boom-bust changes in population size. Yet, while this phenomenon is well-documented in plants, few studies have demonstrated that self-limitation is possible for invasive animal species, especially those that are mobile. Here we examined the invasive Asian shore crab Hemigrapsus sanguineus, a species that reached very high abundances throughout invaded regions of North America, but has recently declined in many of these same regions. We examined the relationship between diet, energy storage, reproduction, and growth in crabs collected from the New Hampshire coast. We show that energy storage and reproduction both increase with diet quality, while growth declines with diet quality. These results suggest that self-limitation may be a contributing factor to the recent declines of H. sanguineus at sites where this invader was once much more abundant. Further, these results suggest a diet-associated tradeoff in energy allocation to different vital rates, with a focus on reproduction when high quality resources are consumed, and a focus instead on growth when poor quality resources are consumed.

RevDate: 2020-10-13

Gissi E, Manea E, Mazaris AD, et al (2020)

A review of the combined effects of climate change and other local human stressors on the marine environment.

The Science of the total environment, 755(Pt 1):142564 pii:S0048-9697(20)36093-9 [Epub ahead of print].

Climate change (CC) is a key, global driver of change of marine ecosystems. At local and regional scales, other local human stressors (LS) can interact with CC and modify its effects on marine ecosystems. Understanding the response of the marine environment to the combined effects of CC and LS is crucial to inform marine ecosystem-based management and planning, yet our knowledge of the potential effects of such interactions is fragmented. At a global scale, we explored how cumulative effect assessments (CEAs) have addressed CC in the marine realm and discuss progress and shortcomings of current approaches. For this we conducted a systematic review on how CEAs investigated at different levels of biological organization ecological responses, functional aspects, and the combined effect of CC and HS. Globally, the effects of 52 LS and of 27 CC-related stressors on the marine environment have been studied in combination, such as industrial fisheries with change in temperature, or sea level rise with artisanal fisheries, marine litter, change in sediment load and introduced alien species. CC generally intensified the effects of LS at species level. At trophic groups and ecosystem levels, the effects of CC either intensified or mitigated the effects of other HS depending on the trophic groups or the environmental conditions involved, thus suggesting that the combined effects of CC and LS are context-dependent and vary among and within ecosystems. Our results highlight that large-scale assessments on the spatial interaction and combined effects of CC and LS remain limited. More importantly, our results strengthen the urgent need of CEAs to capture local-scale effects of stressors that can exacerbate climate-induced changes. Ultimately, this will allow identifying management measures that aid counteracting CC effects at relevant scales.

RevDate: 2020-10-13

Zhang A, Z Xie (2020)

C4 herbs dominate the reservoir flood area of the Three Gorges Reservoir.

The Science of the total environment, 755(Pt 1):142479 pii:S0048-9697(20)36008-3 [Epub ahead of print].

Dam operations can dramatically degenerate riparian vegetation. To improve the restoration practices of reservoir riparian vegetation, it is important to understand which and how a dominant species physiologically and ecologically maintain high fitness in this type of ecosystems. We explored the compositional change of riparian plants during the long-term flood-dry-flood cycle in the reservoir flood area (RFA) of the Three Gorges Reservoir Area (TGRA), China. In total 769 vascular plant species (belonging to 415 genera in 122 families) existed in the study area before damming (prior to 2006, i.e. the natural riparian zone). Following damming (2008-2018), plant species diversity rapidly declined, with only 51 species identified in 2018 (45 genera in 22 families). Before damming, perennial herbs, annual herbs and shrubs co-dominated the study area. After damming, the proportion of shrubs decreased significantly, and the proportion of annuals to total plants increased by 20%. Alien invasive species proportion increased from 5% to 18%. Notably, the proportion of C4 species increased significantly from 7% to 31%. Ten of the 16 dominant species in RFA since 2015 were C4 Poaceae species. Our study indicates that dam construction could cause severe biodiversity loss of riparian plants and draw alien species invasion. Besides, C4 herbs would dominate the RFA. A higher photosynthetic rate could help C4 plants grow faster to cope with the nitrogen deficiency and short growth cycles in RFA. Hence, screening C4 herbs for vegetation restoration might aid in maintaining biodiversity and ecosystem functions in flood-dry-flood reservoir flood areas.

RevDate: 2020-10-10

Johnson JC, JL Williams (2020)

A native annual forb locally excludes a closely related introduced species that co-occurs in oak-savanna habitat remnants.

AoB PLANTS, 12(5):plaa045.

Despite the ubiquity of introduced species, their long-term impacts on native plant abundance and diversity remain poorly understood. Coexistence theory offers a tool for advancing this understanding by providing a framework to link short-term individual measurements with long-term population dynamics by directly quantifying the niche and average fitness differences between species. We observed that a pair of closely related and functionally similar annual plants with different origins-native Plectritis congesta and introduced Valerianella locusta-co-occur at the community scale but rarely at the local scale of direct interaction. To test whether niche and/or fitness differences preclude local-scale long-term coexistence, we parameterized models of competitor dynamics with results from a controlled outdoor pot experiment, where we manipulated densities of each species. To evaluate the hypothesis that niche and fitness differences exhibit environmental dependency, leading to community-scale coexistence despite local competitive exclusion, we replicated this experiment with a water availability treatment to determine if this key limiting resource alters the long-term prediction. Water availability impacted population vital rates and intensities of intraspecific versus interspecific competition between P. congesta and V. locusta. Despite environmental influence on competition our model predicts that native P. congesta competitively excludes introduced V. locusta in direct competition across water availability conditions because of an absence of stabilizing niche differences combined with a difference in average fitness, although this advantage weakens in drier conditions. Further, field data demonstrated that P. congesta densities have a negative effect on V. locusta seed prediction. We conclude that native P. congesta limits abundances of introduced V. locusta at the direct-interaction scale, and we posit that V. locusta may rely on spatially dependent coexistence mechanisms to maintain coexistence at the site scale. In quantifying this competitive outcome our study demonstrates mechanistically how a native species may limit the abundance of an introduced invader.

RevDate: 2020-10-12

Baumgartner NR, SD Ryan (2020)

Interaction of red crabs with yellow crazy ants during migration on Christmas Island.

Mathematical biosciences, 330:108486 pii:S0025-5564(20)30137-1 [Epub ahead of print].

Invasive species have had a profound impact on ecosystems all over the world. Their presence can lead to fundamental changes in the biodiversity of a given ecosystem as well as the extinction of native species. In particular, this work looks at the effect on the Gecarcoidea natalis (Red Crab) population on Christmas Island due to the presence of vast arrays of supercolonies containing Anoplolepis gracilipes (Yellow Crazy Ant). We primarily study the inter-species interaction occurring during the crab migration to the island coast. We propose a microscopic model for the dynamics of the crabs and ants with the goal of increasing crab survival. Through analysis of the model, we investigate a range of potential preventative measures that could be taken to preserve the native crab population dependent on their locations. The main result of this work is that by considering the locations of ant supercolonies incorporated into Monte Carlo simulations of the model, we can identify the order that the supercolonies need to be removed to provide the greatest chance at survival for the crabs per migration cycle.

RevDate: 2020-10-09

Purdon J, Shabangu FW, Yemane D, et al (2020)

Species distribution modelling of Bryde's whales, humpback whales, southern right whales, and sperm whales in the southern African region to inform their conservation in expanding economies.

PeerJ, 8:e9997.

In southern African waters, information about species distribution and habitat preferences of many cetacean species is limited, despite the recent economic growth that may affect them. We determined the relative importance of eight environmental variables (bathymetry, distance to shore, slope, chlorophyll-a, salinity, eastwards sea water velocity, northwards sea water velocity and sea surface temperature) as drivers of seasonal habitat preferences of Bryde's whales (Balaenoptera brydei), humpback whales (Megaptera novaeangliae), southern right whales (Eubalaena australis) and sperm whales (Physeter macrocephalus). Using presence only data from multiple sources, we constructed predictive species distribution models (SDMs) consisting of ensembles of seven algorithms for these species during both summer and winter. Predicted distribution for all cetaceans was high in southern Africa and, in particular, within the South African Exclusive Economic Zone (EEZ). Predictive models indicated a more pronounced seasonal variation for humpback, sperm and southern right whales than for Bryde's whales. Southern right whales occurred closer to shore during winter, humpback whales were more likely to occur along the east coast in winter and the west coast in summer, and sperm whales were more concentrated off the shelf in winter. Our study shows that ensemble models using historical, incidental and scientific data, in conjunction with modern environmental variables, can provide baseline knowledge on important environmental drivers of cetacean distribution for conservation purposes. Results of this study can further be used to help develop marine spatial plans and identify important marine mammal areas.

RevDate: 2020-10-09

Nengovhela A, Denys C, PJ Taylor (2020)

Life history and habitat do not mediate temporal changes in body size due to climate warming in rodents.

PeerJ, 8:e9792.

Temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. Among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. Both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence of a significant temporal response of body size to climate warming but neither have been widely investigated. Using examples of rodents, we predicted that both life history traits and habitat might explain the probability of temporal response using two tests of this hypothesis. Firstly, taking advantage of new data from museum collections spanning the last 106 years, we investigated geographical and temporal variation in cranial size (a proxy for body size) in six African rodent species of two murid subfamilies (Murinae and Gerbillinae) of varying life history, degree of commensality, range size, and habitat. Two species, the commensal Mastomys natalensis, and the non-commensal Otomys unisulcatus showed significant temporal changes in body size, with the former increasing and the latter decreasing, in relation with climate warming. Commensalism could explain the increase in size with time due to steadily increasing food availability through increased agricultural production. Apart from this, we found no general life history or habitat predictors of a temporal response in African rodents. Secondly, in order to further test this hypothesis, we incorporated our data into a meta-analysis based on published literature on temporal responses in rodents, resulting in a combined dataset for 50 species from seven families worldwide; among these, 29 species showed no significant change, eight showed a significant increase in size, and 13 showed a decline in size. Using a binomial logistic regression model for these metadata, we found that none of our chosen life history or habitat predictors could significantly explain the probability of a temporal response to climate warming, reinforcing our conclusion based on the more detailed data from the six African species.

RevDate: 2020-10-06

Elliott M, Rollins L, Bourret T, et al (2020)

First report of leaf blight caused by Phytophthora ramorum on cherry laurel (Prunus laurocerasus) in Washington State, USA.

Plant disease [Epub ahead of print].

In April 2014, Phytophthora ramorum (Werres, De Cock & Man in't Veld) was recovered from symptomatic foliage of cherry laurel (Prunus laurocerasus) at an ornamental plant nursery in Washington State. Cherry laurel, also known as English laurel, is widely propagated in WA because it is commonly used in landscaping. It is invasive in forests near the urban/wildland interface in the western US and in Europe (Rusterholz et al. 2018). Given its popularity as an ornamental species, the potential of this host to spread P. ramorum is of regulatory concern due to possible long distance spread to other states via nursery stock. Foliar symptoms consisted of dark brown lesions near wounds or around leaf margins where water collected. Shot-hole symptoms characterized by abscission zones and dropping of infected tissues were also observed. Lesions expanded beyond the margin of the shot-hole in some cases (Figure S1A). Phytophthora was isolated from symptomatic foliage by surface-sterilizing leaf pieces in 0.6% sodium hypochlorite and 2 rinses in sterile water. They were plated on PARP medium (Ferguson and Jeffers 1999). After 2-3 days, a slow-growing dense colony with coralloid hyphae was isolated onto V8 agar. P. ramorum was identified by observing morphological features (Figure S1B). Colony and spore morphology matched that of P. ramorum (Werres et al. 2001). The isolate was confirmed as P. ramorum by PCR and sequencing of ITS and COX1 regions using primers ITS1/ITS4 (White et al. 1990) and COX1F1/COX1R1 (Van Poucke et al. 2012). Sequences were submitted to GenBank (accession nos. ITS MT031969, COX1 MT031968). BLAST results showed at least 99% similarity with sequences of P. ramorum (ITS, KJ755124 [100%]; COX1, EU124926 [99%]). Multilocus genotyping with microsatellite markers placed the isolate in the EU1 clonal lineage. Pathogenicity of P. ramorum on cherry laurel was confirmed by completing Koch's Postulates using the isolate taken from this host. Two trials were done in a biocontainment chamber (USDA-APHIS permit # 65857) since P. ramorum is a quarantine pathogen and greenhouse trials could not be conducted, using detached stems from mature, visibly healthy cherry laurel plants growing in a landscape. Phytophthora ramorum inoculum was grown on V8A plates at 20®C for 2 weeks until sporangia were abundant. A zoospore suspension was produced by flooding plates with 7 ml sterile water, incubating for 2 hours at 5®C, then 1 hour at 24®C. Zoospores were observed with light microscopy, quantified with a hemocytometer and diluted to 1 x 104 zoospores/ml. A 10 µl droplet was placed at 3 wounded and 3 unwounded sites on 4 leaves per branch. In addition, a set of samples was inoculated by dipping foliage into the zoospore suspension for 30 seconds. A set of controls was mock inoculated using sterile water. Four branches per inoculation treatment were used and the trial was repeated once. Inoculated plant materials were incubated in moist chambers for 3-5 days at 20®C. Free moisture was present on foliage upon removal. Symptom development was assessed after incubation in the biocontainment chamber at 20®C for 7 days (Figure S1C). Phytophthora ramorum was reisolated from symptomatic tissue and the recovered culture was verified morphologically and by PCR and sequencing. It was isolated more often from foliage dipped in zoospore suspension than droplet inoculated, and more from wounded than unwounded sites. None of the water-inoculated controls were positive for P. ramorum. The presence of P. ramorum was also confirmed with DNA extraction from surface-sterilized symptomatic foliage followed by PCR and sequencing of the COX1 gene (EU124926, 100%) (Figure S2). To our knowledge, this is the first report of P. ramorum naturally infecting cherry laurel in the United States. Acknowledgements This work was supported by the USDA National Institute of Food and Agriculture, McIntire-Stennis project 1019284 and USDA APHIS Cooperative Agreement AP17PPQS&T00C070 Literature cited Ferguson and Jeffers, 1999. Plant Disease 83:1129-1136 Van Poucke, K. et al. 2012. Fungal Biology 116: 1178-1191. http://dx.doi.org/10.1016/j.funbio.2012.09.003 Werres, S. et al. 2001. Mycol. Res. 105:1155-1165. White, T. J., et al. 1990. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, CA.

RevDate: 2020-10-06

Zhang Z, Liu Y, Brunel C, et al (2020)

Soil-microorganism-mediated invasional meltdown in plants.

Nature ecology & evolution pii:10.1038/s41559-020-01311-0 [Epub ahead of print].

While most alien species fail to establish, some invade native communities and become widespread. Our understanding of invasion success is derived mainly from pairwise interactions between aliens and natives, while interactions among more than two species remain largely unexplored. Here, we experimentally tested whether and how a third plant species, either native or alien, affected the competitive outcomes between alien and native plants through its soil legacy. We first conditioned soil with one of ten species (six natives and four aliens) or without plants. We then grew on these 11 soils five aliens and five natives without competition, or with intra- or interspecific competition. We found that aliens were not more competitive than natives when grown on soil conditioned by other natives or on non-conditioned soil. However, aliens were more competitive than natives on soil conditioned by other aliens (that is, invasional meltdown). Soil conditioning did not change competitive outcomes by affecting the strength of competition between later plants. Instead, soil conditioned by aliens pushed competitive outcomes towards later aliens by affecting the growth of aliens less negatively than that of natives. Microbiome analysis verified this finding, as we showed that the soil-legacy effects of a species on later species were less negative when their fungal endophyte communities were less similar, and that fungal endophyte communities were less similar between two aliens than between aliens and natives. Our study reveals invasional meltdown in multispecies communities and identifies soil microorganisms as a driver of the invasion success of alien plants.

RevDate: 2020-10-06

McMahan MD (2020)

Assessing Intertidal Populations of the Invasive European Green Crab.

Journal of visualized experiments : JoVE.

Invasive species have caused major disruptions to ecosystems worldwide. The European green crab invaded North America in the 1800s and is considered one of the world's 100 worst invaders by the IUCN. Observations of spatiotemporal green crab population dynamics are essential for predicting and managing the ecological and economic impacts of this harmful invasive species. This protocol was developed in an effort to create a standardized method for assessing green crab population dynamics in the rocky intertidal zone of New England and Atlantic Canada. The protocol was designed to be accessible to multiple users including researchers, educators, students, and citizen scientists. Although it was designed for surveying crab populations, this protocol is easy to adapt and could be used for any number of intertidal species. The resulting data collected using this protocol has a wide range of uses, including to inform ecological research, conservation efforts, mitigation strategies, and fishery development, as well as for educational outreach purposes.

RevDate: 2020-10-06

Maebara Y, Tamaoki M, Iguchi Y, et al (2020)

Genetic Diversity of Invasive Spartina alterniflora Loisel. (Poaceae) Introduced Unintentionally Into Japan and Its Invasion Pathway.

Frontiers in plant science, 11:556039.

Among invasive species, aquatic plants pose serious threats to local biodiversity and ecosystem functions. Spartina alterniflora Loisel. (Poaceae), native to the eastern United States, was introduced unintentionally into Japan (Aichi and Kumamoto Prefectures) at around 2010. This invasive species could easily and rapidly spread to estuarine areas of Japan via vigorous trade and transport, making the prediction of its future invasion necessary. Here, the distribution and structure of the genetic variation of S. alterniflora in Japan were examined using chloroplast DNA (cpDNA) and microsatellite genotyping analyses for clarifying its invasion route and process. According to the cpDNA analysis, S. alterniflora populations in Japan had a single haplotype (haplotype C4) that is the most dominant genotype around the Florida Peninsula, the region of its origin, and is also widely found in the introduced populations in the East Asia. Microsatellite analysis also showed a loss of genetic diversity in Japanese S. alterniflora populations (allelic richness (AR) = 1.20-1.39) compared with that in its native region (AR = 4.58-4.59), suggesting a founder effect on S. alterniflora that might have occurred after invasion of the species into Japan. The principal coordinate analysis and The STRUCTURE analysis indicated that no gene mixing among Japanese local populations (Aichi, northern and southern Kumamoto) was observed, indicating that Spartina invasion occurred independently into these regions. Among the three regions, trading between the ports of northern Kumamoto and the U.S. was obviously lower than trading with China. We concluded that invasive S. alterniflora might have independently invaded Japan at different times through an East Asia route, particularly via China (i.e., secondary introduction). Therefore, it is important to strengthen the quarantine control on the importation of commodities, especially of transport vehicles at potential donor spots (i.e., border control/border biosecurity system), and to share information networks on invasive species between each region/port for minimizing further risks of biological species such as Spartina.

RevDate: 2020-10-06

Langmaier M, K Lapin (2020)

A Systematic Review of the Impact of Invasive Alien Plants on Forest Regeneration in European Temperate Forests.

Frontiers in plant science, 11:524969.

Invasive alien species (IAS) are one of the major threats to global and local biodiversity. In forest ecosystems, the threats caused by IAS include hybridization, transmission of diseases and species competition. This review sets out to analyze the impact of alien plant species on forest regeneration, which we consider to be one of the key stages in tree ecology for the survival of forest ecosystems in the future. The focus of the study is directly relevant to practitioners, forest managers and the conservation management of forests. With this systematic review, we aim to provide an overview of 48 research studies reporting on the impact and/or management of IAS in European temperate forests. We followed a multi-step protocol for compiling the publications for the literature review, with nine search queries producing a total of 3,825 hits. After several reduction rounds, we ended up with a grand total of 48 papers. We identified 53 vascular plant species having a negative influence on forest regeneration in Central European forests. In total, 21 tree species are reported to be impacted by IAS in 24 studies. The results of the review synthesis show that five impact mechanisms affect the regeneration success of native tree species: competition for resources, chemical impact on regeneration, physical impact on regeneration, structural impact on regeneration and indirect impact through interaction with other species. We identified in our synthesis management measures that have been recommended for application at different stages of biological invasions. The associated costs and required resources of management measures are under-reported or not accessible by reviewing the scientific literature. We can thus conclude that it is very import to improve the links between science and practical forest management. We expect that this review will provide direction for invasive plant species research and management aimed at protecting biodiversity in European temperate forest ecosystems.

RevDate: 2020-10-08

Coon JJ, van Riper CJ, Morton LW, et al (2020)

What drives private landowner decisions? Exploring non-native grass management in the eastern Great Plains.

Journal of environmental management, 276:111355 pii:S0301-4797(20)31281-0 [Epub ahead of print].

Non-native grasses used as forage for domestic livestock can negatively impact ecosystem services provided by grasslands. In the U.S., most grazed grasslands are privately owned so the introduction and reduction of non-native grasses are both driven by landowner behavior. Yet, the social factors that shape non-native grass management are rarely explored. To address this knowledge gap, we evaluated how decisions to reduce these grasses through practices such as herbicide application, prescribed fire, and physical removal are influenced by attitudes, norms, and perceived ability. We administered a mixed mode (mailback and online) survey in 2017 to landowners in the eastern Great Plains of the U.S., in a region where cattle production remains the predominant land-use. Using structural equation modeling with parceling, we tested hypotheses related to management decisions derived from a model integrating two theories - the Theory of Planned Behavior and the Norm Activation Model. In this analysis, we identified perceived ability (i.e., access to time, skills, or other necessary resources) as a barrier to adoption for landowners who were already willing to manage non-native grasses. Positive attitudes toward management and increased social norm pressures were both associated with increased sentiments of moral responsibility to reduce non-native grasses. These personal norms, together with attitudes, positively influenced willingness to control non-native grasses. Further, we observed that social norms related to expectations of neighbors had more influence on personal norms than the social norms from natural resource agencies. The power of norms to explain individual management decisions suggests that landowners could be engaged in landscape-scale initiatives by leveraging moral responsibility and influential social groups.

RevDate: 2020-10-08

Dairel M, A Fidelis (2020)

The presence of invasive grasses affects the soil seed bank composition and dynamics of both invaded and non-invaded areas of open savannas.

Journal of environmental management, 276:111291 pii:S0301-4797(20)31215-9 [Epub ahead of print].

One of the major threats to tropical savannas globally is the invasion by alien grasses. In systems frequently disturbed, individuals can be recruited from the seed bank, and areas under natural regeneration can be more easily invaded when exotic newcomers are in the system, including the presence of invasive propagules in the soil seed bank. This study analyzed the dynamics of the soil seed bank in invaded and non-invaded areas of open savannas elucidating the potential of grass regeneration from the seed bank. Soil samples were collected in areas with different invasive grasses: Urochloa brizantha (Hochst. ex A. Rich.) R.D.Webster - synonym Brachiaria brizantha (Hochst. ex A. Rich.) Stapf, Melinis minutiflora Beauv. and areas with native vegetation. Soil seed bank was assessed using two techniques: seed counting and seedling emergence. Dominant species in each area influenced the seed bank composition, showing the highest densities from April to September. In invaded areas, the seed bank was composed mainly of invasive grasses that contributed to 98% (670 ± 382 seeds.m-2) of total seeds. In non-invaded areas, the soil seed bank presented the highest density (65%, 135 ± 38 seeds.m-2) of native species. However, the presence of invasive grasses was significant, with 35% of the total seeds belonging to U. brizantha. Although non-invaded areas have a higher potential for regeneration by native grasses, the presence of invasive grasses in the seed bank is an indication that the invasive species is already in the system and changes in the aboveground cover could accelerate the invasion process. Early management efforts towards establishing and/or established invasive species before seed dispersal could help reduce the soil seed bank load and should be carried out to control and avoid the establishment of African grasses, since they can dominate the seed bank in non-invaded areas if they are present in neighboring areas, affecting the dynamics of plant communities.

RevDate: 2020-10-05

Passantino G, Tursi M, Vercelli C, et al (2020)

Systematic Pathologic Findings Report of Callosciurusfinlaysonii (Horsfield, 1823) (Rodentia, Sciuridae) Squirrels from Maratea area (South Italy) to Investigate Species-Specific Pathologies, Reliability of CO2 Euthanasia Method, and Possible Use as Environmental Sentinels.

Animals : an open access journal from MDPI, 10(10): pii:ani10101771.

The aim of the present study was to macroscopically and microscopically describe the main pathological findings occurring in this invasive species, in order to better understand the real risks for naïve animals and humans. The present study was conducted on Callosciurusfinlaysonii squirrels (n = 165), captured in the Maratea area and euthanatized with CO2 according to a population control of invasive species of the Italian Agriculture Ministry project (ex CIPE project) and conferred to the Department of Veterinary Medicine of Bari (Italy). Macroscopic analysis demonstrated heart, lung, and liver congestion, probably due to the euthanasia method, and variable lesions of bowel, liver, and kidney. The microscopically examination showed the presence of lymphocytic infiltration in the lower layers of the bowel, suggesting enteritis. To the best of our knowledge, this is the first systemic report of gross and microscopical anatomopathological lesions in C.finlaysonii, in South Italy. The results could be useful to fill a gap of knowledge of this species in Italy.

RevDate: 2020-10-03

Lamar SK, Beddows I, CG Partridge (2020)

Examining the molecular mechanisms contributing to the success of an invasive species across different ecosystems.

Ecology and evolution, 10(18):10254-10270.

Invasive species provide an opportune system to investigate how populations respond to new environments. Baby's breath (Gypsophila paniculata) was introduced to North America in the 1800s and has since spread throughout the United States and western Canada. We used an RNA-seq approach to explore how molecular processes contribute to the success of invasive populations with similar genetic backgrounds across distinct habitats. Transcription profiles were constructed from seedlings collected from a sand dune ecosystem in Petoskey, MI (PSMI), and a sagebrush ecosystem in Chelan, WA (CHWA). We assessed differential gene expression and identified SNPs within differentially expressed genes. We identified 1,146 differentially expressed transcripts across all sampled tissues between the two populations. GO processes enriched in PSMI were associated with nutrient starvation, while enriched processes in CHWA were associated with abiotic stress. Only 7.4% of the differentially expressed transcripts contained SNPs differing in allele frequencies of at least 0.5 between populations. Common garden studies found the two populations differed in germination rate and seedling emergence success. Our results suggest the success of G. paniculata in these two environments is likely due to plasticity in specific molecular processes responding to different environmental conditions, although some genetic divergence may be contributing to these differences.

RevDate: 2020-10-03

Bodt LH, Rollins LA, JM Zichello (2020)

Contrasting mitochondrial diversity of European starlings (Sturnus vulgaris) across three invasive continental distributions.

Ecology and evolution, 10(18):10186-10195.

European starlings (Sturnus vulgaris) represent one of the most widespread and problematic avian invasive species in the world. Understanding their unique population history and current population dynamics can contribute to conservation efforts and clarify evolutionary processes over short timescales. European starlings were introduced to Central Park, New York in 1890, and from a founding group of about 100 birds, they have expanded across North America with a current population of approximately 200 million. There were also multiple introductions in Australia in the mid-19th century and at least one introduction in South Africa in the late 19th century. Independent introductions on these three continents provide a robust system to investigate invasion genetics. In this study, we compare mitochondrial diversity in European starlings from North America, Australia, and South Africa, and a portion of the native range in the United Kingdom. Of the three invasive ranges, the North American population shows the highest haplotype diversity and evidence of both sudden demographic and spatial expansion. Comparatively, the Australian population shows the lowest haplotype diversity, but also shows evidence for sudden demographic and spatial expansion. South Africa is intermediate to the other invasive populations in genetic diversity but does not show evidence of demographic expansion. In previous studies, population genetic structure was found in Australia, but not in South Africa. Here we find no evidence of population structure in North America. Although all invasive populations share haplotypes with the native range, only one haplotype is shared between invasive populations. This suggests these three invasive populations represent independent subsamples of the native range. The structure of the haplotype network implies that the native-range sampling does not comprehensively characterize the genetic diversity there. This study represents the most geographically widespread analysis of European starling population genetics to date.

RevDate: 2020-10-03

McCann S, Crossland M, Greenlees M, et al (2020)

Field trials of chemical suppression of embryonic cane toads (Rhinella marina) by older conspecifics.

Ecology and evolution, 10(18):10177-10185.

Laboratory experiments have shown that the viability of embryos of the invasive cane toad (Rhinella marina) can be reduced by exposure to chemical cues from older conspecific larvae. These effects (very strong in laboratory trials) may offer an exciting new approach to controlling this problematic invasive species in Australia. However, the degree to which the method works in natural environments has yet to be assessed.Our experiments in the laboratory and in seminatural outdoor waterbodies show that chemical cues from tadpoles do indeed suppress the growth, development, and survival of conspecific larvae that are exposed as embryos and do so in a dose-dependent manner; higher tadpole densities cause greater suppression of embryos.In seminatural outdoor waterbodies, suppressor-exposed tadpoles were less than half as likely to survive to metamorphosis as were controls, and were much smaller when they did so and hence, less likely to survive the metamorph stage. Additionally, female cane toads were less likely to oviposit in a waterbody containing free-ranging (but not cage-enclosed) tadpoles, suggesting that the presence of tadpoles (rather than the chemical cues they produce) may discourage oviposition.Broadly, our results suggest that the suppression effect documented in laboratory studies does indeed occur in the field also, and hence that we may be able to translate that approach to develop new and more effective ways to reduce rates of recruitment of peri-urban populations of cane toads in their invasive range.

RevDate: 2020-10-03

Pless E, Hopperstad KA, Ledesma N, et al (2020)

Sunshine versus gold: The effect of population age on genetic structure of an invasive mosquito.

Ecology and evolution, 10(18):9588-9599.

The genetic diversity and structure of invasive species are affected by the time since invasion, but it is not well understood how. We compare likely the oldest populations of Aedes aegypti in continental North America with some of the newest to illuminate the range of genetic diversity and structure that can be found within the invasive range of this important disease vector. Aedes aegypti populations in Florida have probably persisted since the 1600-1700s, while populations in southern California derive from new invasions that occurred in the last 10 years. For this comparison, we genotyped 1,193 individuals from 28 sites at 12 highly variable microsatellites and a subset of these individuals at 23,961 single nucleotide polymorphisms (SNPs). This is the largest sample analyzed for genetic structure for either region, and it doubles the number of southern California populations previously analyzed. As predicted, the older populations (Florida) showed fewer indicators of recent founder effect and bottlenecks; in particular, these populations have dramatically higher genetic diversity and lower genetic structure. Geographic distance and driving distance were not good predictors of genetic distance in either region, especially southern California. Additionally, southern California had higher levels of genetic differentiation than any comparably sized documented region throughout the worldwide distribution of the species. Although population age and demographic history are likely driving these differences, differences in climate and transportation practices could also play a role.

RevDate: 2020-10-03

Stastny M, Russell-Mercier JL, RD Sargent (2020)

No evidence that rapid adaptation impedes biological control of an invasive plant.

Evolutionary applications, 13(9):2472-2483.

Biological control is a popular tool for invasive species management, but its success in nature is difficult to predict. One risk is that invasive plants, which may have adapted to lower herbivore pressure in the introduced range, could rapidly evolve defences upon re-association with their biocontrol agent(s). Previous studies have demonstrated that populations of the invasive plant purple loosestrife (Lythrum salicaria) exposed to biocontrol exhibit traits consistent with the rapid evolution of defence. However, to date, no one has tested this hypothesis under field-natural levels of herbivory. Using seed from 17 populations of purple loosestrife growing in eastern Canada, that varied in their history of exposure to their biocontrol agent, the leaf beetle Neogalerucella spp., we transplanted 1,088 seedlings from 136 maternal families into a common garden under ambient herbivory. Over the following three and half years, we assessed plant performance in the face of biocontrol by measuring early-season plant size, defoliation, flowering, and season-end biomass. We discovered that a population history with biocontrol explained little variation in herbivory or plant performance, suggesting that adaptation is not hindering biocontrol effectiveness. Instead, plant size, subsequent defoliation, and spatio-temporal variables were the main predictors of plant growth and flowering during the study. The high individual variability we observed in plant performance underscores that flexible strategies of allocation and phenology are important contributors to the persistence of invasive plants. Our findings suggest that plant adaptation to biocontrol is unlikely to be a strong impediment to biological control in this species, however, the high survival and variable defoliation of plants in our study also indicate that biocontrol alone is unlikely to result in significant population decline. We recommend that the application of multiple forms of control simultaneously (e.g. thinning plus biocontrol) could help to prevent the existence of refuges of large, reproductive individuals.

RevDate: 2020-10-03

Li J, Aidlin Harari O, Doss AL, et al (2020)

Can CRISPR gene drive work in pest and beneficial haplodiploid species?.

Evolutionary applications, 13(9):2392-2403.

Gene drives based on CRISPR/Cas9 have the potential to reduce the enormous harm inflicted by crop pests and insect vectors of human disease, as well as to bolster valued species. In contrast with extensive empirical and theoretical studies in diploid organisms, little is known about CRISPR gene drive in haplodiploids, despite their immense global impacts as pollinators, pests, natural enemies of pests, and invasive species in native habitats. Here, we analyze mathematical models demonstrating that, in principle, CRISPR homing gene drive can work in haplodiploids, as well as at sex-linked loci in diploids. However, relative to diploids, conditions favoring the spread of alleles deleterious to haplodiploid pests by CRISPR gene drive are narrower, the spread is slower, and resistance to the drive evolves faster. By contrast, the spread of alleles that impose little fitness cost or boost fitness was not greatly hindered in haplodiploids relative to diploids. Therefore, altering traits to minimize damage caused by harmful haplodiploids, such as interfering with transmission of plant pathogens, may be more likely to succeed than control efforts based on introducing traits that reduce pest fitness. Enhancing fitness of beneficial haplodiploids with CRISPR gene drive is also promising.

RevDate: 2020-10-04

Urbina J, Bredeweg EM, Cousins C, et al (2020)

Reproductive characteristics of American bullfrogs (Lithobates catesbeianus) in their invasive range of the Pacific Northwest, USA.

Scientific reports, 10(1):16271.

Invasive species pose a major threat to global biodiversity. The effects of invasive species can be strongly influenced and potentially mediated by their reproductive characteristics, such as fecundity, egg production, and duration and number of reproductive events. Selection for smaller body size at first reproduction can also play a role in their establishment, facilitating colonization and spread. The American bullfrog, native to the eastern U.S. (Lithobates catesbeianus), is a species that has invaded more than 40 countries across 4 continents. This species has become especially prevalent in the western United States since its introduction in the early 1900s. This study characterized reproductive characteristics of bullfrogs with emphasis on the minimum size at which males and females reach sexual maturity in the Willamette Valley, Oregon, USA invasion range. We collected and dissected 121 individuals in 2013 and 2017, quantifying characteristics of sexual maturity including snout-vent length, total length, sex, tympanum diameter, presence of distended oviducts or eggs for females, and testes length and sperm activity in males. Our results showed that the minimum reproductive size of both males and females was smaller relative to bullfrogs in their native range as well as in populations across their invasive range. Reduction in size at reproductive maturity is likely impacting the invasive success of American bullfrogs and this study gives us insight on management actions to control the invasion. Applying this insight, managers can adjust their definition of reproductively active adults, increasing the target population of culling and other control methods.

RevDate: 2020-10-01

Sarmento MI, Pinto G, Araújo WL, et al (2020)

Differential development time of galls induced by Leptocybe invasa (Hymenoptera: Eulophidae) reveal differences in susceptibility between two Eucalyptus clones.

Pest management science [Epub ahead of print].

BACKGROUND: The significance of morphological responses of hosts on susceptibility against gall-inducing insects are relatively unknown specially in planted forests. Here, we investigate the temporal morphological responses (gall development) induced by the invasive gall wasp Leptocybe invasa and the subsequent insect development in two Eucalyptus clones.

RESULTS: Our results identified a novel stage of gall development, not previously reported, termed here "brownish ring." In both hosts similar gall development stages were observed. Although L. invasa oviposited in both clones, comparison of external morphological traits of galls over time revealed a differential response in the number of galls between clones. Comparison of the developmental time of each gall and insect stage between clones suggests that plant defense mechanisms against L. invasa are activated shortly after oviposition by the wasp, yet before gall formation.

CONCLUSION: Gall number is an important parameter that should be used to measure host susceptibility among Eucalyptus clones. To our best knowledge, this is the first study showing differential morphological responses induced by a galling insect, even before gall formation, revealing differences in susceptibility between different plant hosts. These findings provide insight into to use of early stages of galls formation by L. invasa to prevent invasion and establishment of this pest.

RevDate: 2020-10-01

Seebens H, Bacher S, Blackburn TM, et al (2020)

Projecting the continental accumulation of alien species through to 2050.

Global change biology [Epub ahead of print].

Biological invasions have steadily increased over recent centuries. However, we still lack a clear expectation about future trends in alien species numbers. In particular, we do not know whether alien species will continue to accumulate in regional floras and faunas, or whether the pace of accumulation will decrease due to the depletion of native source pools. Here, we apply a new model to simulate future numbers of alien species based on estimated sizes of source pools and dynamics of historical invasions, assuming a continuation of processes in the future as observed in the past (a business-as-usual scenario). We first validated performance of different model versions by conducting a back-casting approach, therefore fitting the model to alien species numbers until 1950 and validating predictions on trends from 1950 to 2005. In a second step, we selected the best performing model that provided the most robust predictions to project trajectories of alien species numbers until 2050. Altogether, this resulted in 3,790 stochastic simulation runs for 38 taxon-continent combinations. We provide the first quantitative projections of future trajectories of alien species numbers for seven major taxonomic groups in eight continents, accounting for variation in sampling intensity and uncertainty in projections. Overall, established alien species numbers per continent were predicted to increase from 2005 to 2050 by 36%. Particularly, strong increases were projected for Europe in absolute (+2,543 ± 237 alien species) and relative terms, followed by Temperate Asia (+1,597 ± 197), Northern America (1,484 ± 74) and Southern America (1,391 ± 258). Among individual taxonomic groups, especially strong increases were projected for invertebrates globally. Declining (but still positive) rates were projected only for Australasia. Our projections provide a first baseline for the assessment of future developments of biological invasions, which will help to inform policies to contain the spread of alien species.

RevDate: 2020-10-01

Liu C, Ren Y, Li Z, et al (2020)

Giant african snail genomes provide insights into molluscan whole-genome duplication and aquatic-terrestrial transition.

Molecular ecology resources [Epub ahead of print].

Whole-genome duplication (WGD), contributing to evolutionary diversity and environmental adaptability, has been observed across a wide variety of eukaryotic groups, but not in mollusks. Mollusks are the second largest animal phylum in species numbers, and among the organisms that have successfully adapted to the nonmarine realm through aquatic-terrestrial (A-T) transition. We assembled a chromosome-level reference genome for Achatina immaculata, a global invasive species, and compared the genomes of two giant African snails (A. immaculata and Achatina fulica) to the other available mollusk genomes. The macrosynteny, colinearity blocks, Ks peak and Hox gene clusters collectively suggested the WGD event in the two snails. The estimated WGD timing (~70 MYA) was close to the speciation age of the Sigmurethra-Orthurethra (within Stylommatophora) lineage and the Cretaceous-Tertiary (K-T) mass extinction, indicating that the WGD may have been a common event shared by all Sigmurethra-Orthurethra species and conferred ecological adaptability allowing the K-T extinction survival. Further, the adaptive mechanism of WGD in terrestrial ecosystems was confirmed by the gene families related to the respiration, aestivation and immune defense. Several mucus-related gene families expanded early in the Stylommatophora lineage, and the hemocyanins, phosphoenolpyruvate carboxykinase families were doubled during WGD, and zinc metalloproteinase genes were highly tandemly duplicated after WGD. Theses evidence suggests that although the WGD may not have been the direct driver of the A-T transition, it provided an important legacy for the terrestrial adaptation of the giant African snails.

RevDate: 2020-09-30

Culverwell CL, Uusitalo RJ, Korhonen EM, et al (2020)

The mosquitoes of Finland: updated distributions and bionomics.

Medical and veterinary entomology [Epub ahead of print].

Mosquitoes (Diptera: Culicidae) were collected in Finland between 2012 and 2018 to determine the species present and their distributions. In total, 52 466 specimens from 1031 collections formed the basis for the preparation of distribution maps for each of the 40 species that were collected. Anopheles maculipennis s.s., An. claviger, Aedes geminus and Ochlerotatus sticticus are confirmed on mainland Finland after previous records were uncertain or absent. Coquillettidia richiardii, Culiseta morsitans, Cs. ochroptera, Culex territans, Cx. torrentium, Oc. leucomelas, Oc. nigrinus, Oc. pullatus and Oc. punctodes occur more widely than previously reported. Three species, Ae. rossicus, Cs. subochrea and Oc. cyprius were not collected, although Ae. rossicus was subsequently found in Lapland by another researcher. No invasive species were collected. Ochlerotatus communis, an aggressive biter, was the most commonly encountered species. Larval collection data suggest that several species may have up to three generations per year in Finland, with Cx. torrentium and Cx. pipiens having at least two, and Oc. communis and Oc. punctor regularly found as larvae across the summer. These data, especially when coupled with historical records, are vital for monitoring species which have significant vector potential, particularly when faced with a warming climate.

RevDate: 2020-10-07

Ekanayake EMBP, Cirella GT, Y Xie (2020)

Impacts of community forestry on forest condition: Evidence from Sri Lanka's intermediate zone.

PloS one, 15(9):e0239405.

Sri Lanka's community forestry (CF) program emerged in the early 1980s following a global trend to conserve forest resources and provide benefits to the local community. However, very little is known about the effect of CF on forest resources. We assess the impacts of CF on forest conditions of semi-mixed evergreen forest in the intermediate zone of Sri Lanka using the before-after control-impact method. The study examines tree density, regeneration, woody species diversity, and evidence of disturbance as parameters to analyze the impact of the CF program. Data are analyzed using the difference in differences approach. The results show that the CF program has increased seedling and sapling density to a significant degree and reduced human disturbances. A major contribution of the CF program is that it was found to reduce invasive species and forest fires. The program reduced the amount of invasive species up to six times less than previous. The findings revealed that the impact of CF on forests may vary depending on pre-existing forest conditions, length of period to implement, perception, and decisions by local people. Community understanding and decision-making, in tandem with government policy, will weigh heavily on its future effectiveness.

RevDate: 2020-09-30

Landis WG (2020)

The origin, development, application, lessons learned, and future regarding the Bayesian Network Relative Risk Model for ecological risk assessment.

Integrated environmental assessment and management [Epub ahead of print].

In 2012 a regional risk assessment was published that applied Bayesian networks to the structure of the relative risk model. The original structure of the relative risk model (RRM) was published in the late 1990s and developed during the next decade. The RRM coupled with a Monte Carlo analysis was applied to calculating risk to a number of sites and a variety of questions. The sites included watersheds, terrestrial systems, and marine environments and included stressors such as nonindigenous species, effluents, pesticides, nutrients, and management options. However, it became apparent that there were limits to the original approach. In 2009, the relative risk model was transitioned into the structure of a Bayesian network (BN). Bayesian networks had several clear advantages. First, BNs innately incorporated categories and as in the case of the relative risk model, ranks to describe systems. Second, interactions between multiple stressors can be combined using several pathways and the conditional probability tables (CPT) to calculate outcomes. Entropy analysis was the method used to document model sensitivity. As with the RRM, the method has now been applied to a wide series of sites and questions, from forestry management, to invasive species, to disease, the interaction of ecological and human health endpoints, the flows of large rivers, and now the efficacy and risks of synthetic biology. The application of both methods have pointed to the incompleteness of the fields of environmental chemistry, toxicology and risk assessment. The low frequency of exposure-response experiments and proper analysis have limited the available outputs for building appropriate CPTs. Interactions between multiple chemicals, landscape characteristics, population dynamics and community structure have been poorly characterized even for critical environments. A better strategy might have been to first look at the requirements of modern risk assessment approaches and then set research priorities. This article is protected by copyright. All rights reserved.

RevDate: 2020-09-30

Milosavljević I, Hoddle CD, Mafra-Neto A, et al (2020)

Use of Digital Video Cameras to Determine the Efficacy of Two Trap Types for Capturing Rhynchophorus palmarum (Coleoptera: Curculionidae).

Journal of economic entomology pii:5909748 [Epub ahead of print].

The efficacies of two trap types, bucket and Picusan traps, for capturing and retaining Rhynchophorus palmarum (L.), an invasive palm pest responsible for killing thousands of ornamental Canary Islands date palms (Phoenix canariensis Chabaud [Arecales: Arecaceae]) in San Diego County, CA, were compared. Digital video data were analyzed to determine how R. palmarum behavior toward each trap type affected capture and retention rates. Videography was conducted 24 h/d, 7 d/wk, for more than 7 mo resulting in 20,211 h of digital data for analysis. Weevil attraction to traps was observed only during daylight hours and no patterns in diel activity were found. Neither trap type tested captured 100% of weevils attracted to traps. Bucket traps suspended 1.5 m above the ground attracted 30% more weevils than ground deployed Picusan traps. Of those weevils attracted to bucket traps, 89% entered, 82% escaped, and 18% that entered traps were retained. Weevils that were not retained spent an average of 19 min 20 s entering and exiting entry holes and walking and flying around the bucket trap. By contrast, Picusan traps captured 89% of weevils that entered the trap. The time between weevils arriving (via walking or flight) on the sides of the Picusan trap and retention in the trap ranged between 90 and 376 s. These visual observations suggest that Picusan traps are more efficient than bucket traps for R. palmarum capture.

RevDate: 2020-10-02

Rugman-Jones PF, Au M, Ebrahimi V, et al (2020)

One becomes two: second species of the Euwallacea fornicatus (Coleoptera: Curculionidae: Scolytinae) species complex is established on two Hawaiian Islands.

PeerJ, 8:e9987.

The cryptic species that make up the Euwallacea fornicatus species complex can be readily distinguished via their DNA sequences. Until recently, it was believed that the Hawaiian Islands had been invaded by only one of these cryptic species, E. perbrevis (tea shot hole borer; TSHB). However, following the 2016 deposition of a DNA sequence in the public repository GenBank, it became evident that another species, E. fornicatus (polyphagous shot hole borer; PSHB), had been detected in macadamia orchards on Hawai'i Island (the Big Island). We surveyed the two most-populous islands of Hawai'i, Big Island and O'ahu, and herein confirm that populations of TSHB and PSHB are established on both. Beetles were collected using a variety of techniques in macadamia orchards and natural areas. Individual specimens were identified to species using a high-resolution melt assay, described herein and validated by subsequent sequencing of specimens. It remains unclear how long each species has been present in the state, and while neither is currently recognized as causing serious economic or ecological damage in Hawai'i, the similarity of the newly-confirmed PSHB population to other damaging invasive PSHB populations around the world is discussed. Although the invasive PSHB populations in Hawai'i and California likely have different geographic origins within the beetle's native range, they share identical Fusarium and Graphium fungal symbionts, neither of which have been isolated from PSHB in that native range.

RevDate: 2020-10-02

Tufts DM, Sameroff S, Tagliafierro T, et al (2020)

A metagenomic examination of the pathobiome of the invasive tick species, Haemaphysalis longicornis, collected from a New York City borough, USA.

Ticks and tick-borne diseases, 11(6):101516.

Haemaphysalis longicornis, the Asian longhorned tick, is an invasive tick species that has spread rapidly across the northeastern and southeastern regions of the United States in recent years. This invasive pest species, known to transmit several tick-borne pathogens in its native range, is a potential threat to wildlife, livestock, domestic animals, and humans. Questing larval (n = 25), nymph (n = 10), and adult (n = 123), along with host-derived adult (n = 25) H. longicornis ticks were collected from various locations on Staten Island, NY. The pathobiome of each specimen was examined using two different high throughput sequencing approaches, virus enrichment and shotgun metagenomics. An average of 45,828,061 total reads per sample were recovered from the virus enriched samples and an average of 11,381,144 total reads per sample were obtained using shotgun metagenomics. Aside from endogenous viral sequences, no viruses were identified through either approach. Through shotgun metagenomics, Coxiella-like bacteria, Legionella, Sphingomonas, and other bacterial species were recovered. The Coxiella-like agent was ubiquitous and present at high abundances in all samples, suggesting it may be an endosymbiont. The other bacterial agents are not known to be transmitted by ticks. From these analyses, H. longicornis do not appear to host any endemic human tick-borne pathogens in the New York City region.

RevDate: 2020-10-02

Assaeed AM, Al-Rowaily SL, El-Bana MI, et al (2020)

Functional Traits Plasticity of the Invasive Herb Argemone ochroleuca Sweet in Different Arid Habitats.

Plants (Basel, Switzerland), 9(10): pii:plants9101268.

Understanding the strategies and mechanisms of invasive species could guide their control and management especially in arid ecosystems. This study compares the vegetative and reproductive functional traits of the invasive Mexican poppy (Argemone ochroleuca), in seven habitat types, in southwestern Saudi Arabia. The results showed that the aboveground phenological attributes such as plant height, leaf area, and leaf dry mass attained the highest values in the wadi channels, whereas these attributes attained the lowest values in the mountain ranges. Maximum specific leaf area, root parameters, and all reproductive traits were recorded in the abandoned fields. In contrast to all other habitats, populations from abandoned fields had a greater investment of resources in belowground structures, while the population growing in the wadi channels and mountain ranges habitat allocated more energy to vegetative parts. The plasticity in vegetative and reproductive resource allocation in A. ochroleuca is an important mechanism in determining its colonizing ability in different habitat types and expanding the distribution range. The present data of the functional traits of A. ochroleuca agree with the resource fluctuation hypothesis, where the plant flourished in the abandoned fields that attained the highest values of organic matter and nutrients. Therefore, the restoration of these disturbed habitats could improve the resistance toward invasion by this noxious weed.

RevDate: 2020-09-29

Knapp L, Mazzi D, R Finger (2020)

The economic impact of Drosophila suzukii: perceived costs and revenue losses of Swiss cherry, plum and grape growers.

Pest management science [Epub ahead of print].

BACKGROUND: Drosophila suzukii can lead to substantial damages in horticultural production. In this article we analyze revenue losses and cost increases due to D. suzukii as perceived of Swiss cherry, plum and grape growers. Moreover, we investigate associations between farm and grower characteristics and revenue losses and perceived costs increases. We surveyed Swiss growers of cherries, plums and grapes repeatedly in the period 2016-2018 (N = 1572).

RESULTS: We find that 76% of cherry, plum and grape growers faced additional costs due to D. suzukii. In contrast, yield losses due to D. suzukii infestation were small on average, but nevertheless high for some growers. We find substantial heterogeneity in perceived costs and revenue losses across crops, years and farms. Larger farms are found to face lower perceived additional costs, suggesting scale effects in prevention and control of D. suzukii. Growers with a higher inter-varietal diversity perceived additional costs to be higher. Furthermore, organic farming was negatively associated with expected additional costs.

CONCLUSION: Our results suggest that the economic impact of invasive species such as D. suzukii goes far beyond reductions in yield quantity and quality, but rather stems from higher costs due to the need to establish preventive and control measures. Heterogeneity in costs and revenue losses suggests that policy measures to support growers need to be tailored to crops and farm types. Policies supporting improvements of measures against D. suzukii and other newly occurring alien pests and reduce additional costs such as more efficient preventive and control measures merit further encouragement. This article is protected by copyright. All rights reserved.

RevDate: 2020-09-29

Thusithana V, Amarasekara RWK, Jayasuriya KMGG, et al (2020)

Seed dormancy of cardiospermum halicacabum (sapindaceae) from three precipitation zones in sri lanka.

Plant biology (Stuttgart, Germany) [Epub ahead of print].

This study investigated seed germination of Cardiospermum halicacabum, a medicinally-important invasive species. We compared mass, moisture content (MC), dormancy and dormancy-breaking treatments and imbibition and germination of scarified and nonscarified seeds of C. halicacabum from a low-elevation dry zone (DZ), low-elevation wet zone (WZ1) and mid-elevation wet zone (WZ2) in Sri Lanka to test the hypothesis that the percentage of seeds with water-impermeable seed coats (physical dormancy, PY) decreases with increased precipitation. Seed mass was higher in WZ2 than in DZ and WZ1, while seed MC did not vary among the zones. All scarified DZ, WZ1 and WZ2 and non-scarified DZ and WZ1 seeds imbibed water, but only a few non-scarified WZ2 seeds did so. When DZ and WZ1 seeds were desiccated, MC and percentage imbibition decreased, showing that these seeds have the ability to develop PY. GA3 promoted germination of embryos excised from fresh DZ and WZ1 seeds and of scarified WZ2 seeds. At maturity, seeds from DZ and WZ1 had only physiological dormancy (PD), while those from WZ2 had combinational dormancy (PY+PD). Thus, our hypothesis was not supported. Since a high percentage of excised embryos developed into normal seedlings; this is a low-cost method to produce C. halicacabum plants for medicinal and ornamental purposes.

RevDate: 2020-10-12

Braschler B, Duffy GA, Nortje E, et al (2020)

Realised rather than fundamental thermal niches predict site occupancy: Implications for climate change forecasting.

The Journal of animal ecology [Epub ahead of print].

Thermal performance traits are regularly used to make forecasts of the responses of ectotherms to anthropogenic environmental change, but such forecasts do not always differentiate between fundamental and realised thermal niches. Here we determine the relative extents to which variation in the fundamental and realised thermal niches accounts for current variation in species abundance and occupancy and assess the effects of niche-choice on future-climate response estimations. We investigated microclimate and macroclimate temperatures alongside abundance, occupancy, critical thermal limits and foraging activity of 52 ant species (accounting for >95% individuals collected) from a regional assemblage from across the Western Cape Province, South Africa, between 2003 and 2014. Capability of a species to occupy sites experiencing the most extreme temperatures, coupled with breadth of realised niche, explained most deviance in occupancy (up to 75%), while foraging temperature range and body mass explained up to 50.5% of observed variation in mean species abundance. When realised niches are used to forecast responses to climate change, large positive and negative effects among species are predicted under future conditions, in contrast to the forecasts of minimal impacts on all species that are indicated by fundamental niche predictions.

LOAD NEXT 100 CITATIONS

RJR Experience and Expertise

Researcher

Robbins holds BS, MS, and PhD degrees in the life sciences. He served as a tenured faculty member in the Zoology and Biological Science departments at Michigan State University. He is currently exploring the intersection between genomics, microbial ecology, and biodiversity — an area that promises to transform our understanding of the biosphere.

Educator

Robbins has extensive experience in college-level education: At MSU he taught introductory biology, genetics, and population genetics. At JHU, he was an instructor for a special course on biological database design. At FHCRC, he team-taught a graduate-level course on the history of genetics. At Bellevue College he taught medical informatics.

Administrator

Robbins has been involved in science administration at both the federal and the institutional levels. At NSF he was a program officer for database activities in the life sciences, at DOE he was a program officer for information infrastructure in the human genome project. At the Fred Hutchinson Cancer Research Center, he served as a vice president for fifteen years.

Technologist

Robbins has been involved with information technology since writing his first Fortran program as a college student. At NSF he was the first program officer for database activities in the life sciences. At JHU he held an appointment in the CS department and served as director of the informatics core for the Genome Data Base. At the FHCRC he was VP for Information Technology.

Publisher

While still at Michigan State, Robbins started his first publishing venture, founding a small company that addressed the short-run publishing needs of instructors in very large undergraduate classes. For more than 20 years, Robbins has been operating The Electronic Scholarly Publishing Project, a web site dedicated to the digital publishing of critical works in science, especially classical genetics.

Speaker

Robbins is well-known for his speaking abilities and is often called upon to provide keynote or plenary addresses at international meetings. For example, in July, 2012, he gave a well-received keynote address at the Global Biodiversity Informatics Congress, sponsored by GBIF and held in Copenhagen. The slides from that talk can be seen HERE.

Facilitator

Robbins is a skilled meeting facilitator. He prefers a participatory approach, with part of the meeting involving dynamic breakout groups, created by the participants in real time: (1) individuals propose breakout groups; (2) everyone signs up for one (or more) groups; (3) the groups with the most interested parties then meet, with reports from each group presented and discussed in a subsequent plenary session.

Designer

Robbins has been engaged with photography and design since the 1960s, when he worked for a professional photography laboratory. He now prefers digital photography and tools for their precision and reproducibility. He designed his first web site more than 20 years ago and he personally designed and implemented this web site. He engages in graphic design as a hobby.

Support this website:
Order from Amazon
We will earn a commission.

This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

963 Red Tail Lane
Bellingham, WA 98226

206-300-3443

E-mail: RJR8222@gmail.com

Collection of publications by R J Robbins

Reprints and preprints of publications, slide presentations, instructional materials, and data compilations written or prepared by Robert Robbins. Most papers deal with computational biology, genome informatics, using information technology to support biomedical research, and related matters.

Research Gate page for R J Robbins

ResearchGate is a social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a study by Nature and an article in Times Higher Education , it is the largest academic social network in terms of active users.

Curriculum Vitae for R J Robbins

short personal version

Curriculum Vitae for R J Robbins

long standard version

RJR Picks from Around the Web (updated 11 MAY 2018 )