EEOB publications :: February 1- February 28
Roundup and immune challenge have different effects on a native field cricket and its introduced competitor
Mullins LR, Brown DJ, Lovsey SR, Bowers TA, Gershman SN. 2023. Research Square. DOI: 10.21203/rs.3.rs-2440526/v1
Crickets face many natural selection pressures, and humans have added to this burden by applying potentially harmful herbicides and unintentionally introducing competitors. We examine recently introduced Velafictorus micado Japanese burrowing crickets which share a microhabitat and season with native Gryllus pennsylvanicus field crickets. In this study, we assess the combined effects of Roundup (glyphosate-based herbicide) and a lipopolysaccharide (LPS) immune challenge on both crickets. In both species, an immune challenge reduced the numbers of eggs that female laid, however, this effect was much larger in G. pennsylvanicus . Conversely, Roundup caused both species to increase egg production, potentially representing a terminal investment strategy. The combined effect of immune challenge and herbicide harmed G. pennsylvanicus fecundity more than V. micado fecundity. Further, V. micado females laid significantly more eggs than G. pennsylvanicus , suggesting that introduced V. micado may have a competitive edge in fecundity over native G. pennsylvanicus . LPS and Roundup each had differing effects on male G. pennsylvanicus and V. micado calling effort. Overall, introduced male V. micado spent significantly more time calling than native G. pennsylvanicus , which could potentially interfere with G. pennsylvanicus mate-location behavior in their shared natural habitat. Despite the population-level spread of introduced V. micado, in our study, this species did not outperform native G. pennsylvanicus in tolerating immune and chemical challenge. Although V. micado appears to possess traits that make this introduced species successful in colonizing new habitats, it may be less successful in traits that would allow it to outcompete a native species.
The genome of the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera, Scelionidae), a model organism and biocontrol agent of stink bugs
Zachary Lahey, Huayan Chen, Mark Dowton, Andrew D. Austin, Norman F. Johnson. Journal of Hymenoptera Research 95: 31–44. https://doi.org/10.3897/jhr.95.97654
Trissolcus basalis (Wollaston) is a minute parasitic wasp that develops in the eggs of stink bugs. Over the past 30 years, Tr. basalis has become a model organism for studying host finding, patch defense behavior, and chemical ecology. As an entry point to better understand the molecular basis of these factors, in addition to filling a critical gap in the genomic resources available for parasitic Hymenoptera, we sequenced and assembled the genome of Tr. basalis using short (454, Illumina) and long read (Oxford Nanopore) sequencing technologies. The three sequencing methods produced 32 million reads (4.10 Gb; 27.9×), which were assembled into 7,586 scaffolds. The 147 Mb (N50: 42.8 kb) assembly contains complete sequences for 93.1% of the insect BUSCO dataset, and an extensive annotation protocol resulted in 14,158 protein-coding gene models, 12,197 (86%) of which had a blast hit in GenBank. Repetitive elements comprised 13.8% of the genome, and a phylogenomic analysis recovered Tr. basalis as sister to Chalcidoidea, a result in line with other studies. We identified 174 rapidly evolving gene families in Tr. basalis, including olfactory receptors and pheromone/general odorant binding proteins. These genetic elements are an obligatory portion of the parasitoid-host relationship, and the draft genome of Tr. basalis has and will continue to be useful in elucidating these relationships at finer resolution.
Synthesizing Professional Opinion and Published Science to Build a Conceptual Model of Walleye Recruitment
Corey A. Krabbenhoft, Stuart A. Ludsin, Elizabeth A. Marschall, Richard R. Budnik, L. Zoe Almeida, Holly S. Embke, Zachary S. Feiner, Patrick J. Schmalz, Matt J. Thorstensen, Michael J. Weber, Melissa R. Wuellner, Gretchen J.A. Hansen. 2023. Fisheries published by Wiley Periodicals LLC on behalf of American Fisheries Society. DOI: 10.1002/fsh.10884
Understanding and predicting recruitment, longstanding goals in fisheries science and ecology, are complicated by variation in the importance of environmental drivers coupled with the dynamic nature of individual ecosystems. Developing an understand- ing of recruitment from well-monitored stocks offers an opportunity to overcome these complexities. We used a systematic literature review, a survey, and a workshop attended by professionals with expertise in recruitment of Walleye Sander vitreus to identify common environmental drivers of Walleye recruitment and additional sources of variation (i.e., context dependencies) among populations. The importance of individual environmental drivers, as well as the direction of their influence, differed as a function of geographic region, lake surface area, and Walleye life stage. The literature suggested abiotic conditions (e.g., tempera- ture) during the first year of life were influential in determining recruitment. Professional opinion noted the importance of biotic factors, with prey availability and predation risk having the most consistent relationships with recruitment. We synthesized this information to propose a conceptual model that illustrates the suite of characteristics that shape Walleye recruitment over large spatial and temporal scales. Our findings emphasize the importance of first-year growth and system-specific contextual factors, which can alter the relative importance of the environmental drivers of recruitment.
Single-cell atavism reveals an ancient mechanism of cell type diversification in a sea anemone
Leslie S. Babonis, Camille Enjolras, Abigail J. Reft, Brent M. Foster, Fredrik Hugosson, Joseph F. Ryan, Marymegan Daly & Mark Q. Martindale. Nature Communications volume 14, Article number: 885 (2023)
Cnidocytes are the explosive stinging cells unique to cnidarians (corals, jellyfish, etc). Specialized for prey capture and defense, cnidocytes comprise a group of over 30 morphologically and functionally distinct cell types. These unusual cells are iconic examples of biological novelty but the developmental mechanisms driving diversity of the stinging apparatus are poorly characterized, making it challenging to understand the evolutionary history of stinging cells. Using CRISPR/Cas9-mediated genome editing in the sea anemone Nematostella vectensis, we show that a single transcription factor (NvSox2) acts as a binary switch between two alternative stinging cell fates. Knockout of NvSox2 causes a transformation of piercing cells into ensnaring cells, which are common in other species of sea anemone but appear to have been silenced in N. vectensis. These results reveal an unusual case of single-cell atavism and expand our understanding of the diversification of cell type identity.
Bumble bee banquet: Genus- and species-level floral selection by Midwestern Bombus
Jessie Lanterman Novotny, Andrew Lybbert, Paige Reeher, Randall J. Mitchell, Karen Goodell. Ecosphere. 2023;14:e4425. https://doi.org/10.1002/ecs2.4425
Regionally specific flower preference data are needed to optimize conservation habitat plantings for at-risk pollinators such as bumble bees (Bombus spp.). Current tools for selecting flowers for plantings rely on raw bee flower visits, which can be biased toward abundant flowers. To assist in planning habitat enhancements for bumble bees, we quantified genus- and species-level floral preferences using a selection index that accounts for floral availability. Through 477 h of observation in Ohio, USA during the summers of 2017 and 2018, we recorded 22,999 observations of eight Bombus species visiting 96 flowering plant taxa. As a genus, Bombus selected flowers nonrandomly; the most strongly preferred plants included Asclepias spp., Cirsium spp., Convolvulaceae, Dipsacus spp., Echinacea purpurea, Monarda fistulosa, Penstemon digitalis, and Silphium spp. Only a few Fabaceae were highly selected (Baptisia spp., Trifolium pratense, and Vicia spp.), while some were preferred only during their peak bloom (Securigera varia), and others were not preferred by bumble bees (T. hybridum and Melilotus spp.). Diets differed among habitats, and in restored meadows, bumble bees selected for native planted species such as Monarda fistulosa, Asclepias syriaca, Echinacea purpurea, Penstemon digitalis, and Silphium spp. Diets and prefer- ences shifted over the season, largely driven by changes in plant phenologies (e.g., in June, Penstemon was strongly selected, in July, Asclepias, and in August, Verbena). For the three most common Bombus (B. impatiens, B. griseocollis, and B. bimaculatus), rarefaction analysis indicates that we were able to detect almost all plants in their summer diets. However, for five less common species, even our extensive sampling was insufficient to fully charac- terize their diets. The common Bombus species differed in their feeding niches, perhaps reducing interspecific competition. In contrast, we found high diet overlap between three rarer species—B. vagans, B. fervidus, and B. pensylvanicus, suggesting that these at-risk species might benefit from different floral communities than would the common species. Five of eight species (including one that is currently under review for federal listing) most strongly preferred one or another non-native plant, presenting managers with a conser- vation conundrum concerning how to balance the needs of bees with the preservation of native plants.