Kaylee earns best talk award at ESA!

Our very own Kaylee Arnold won best talk for her presentation, “The gut microbial diversity of a Chagas disease vector varies across coinfection status throughout central Panama” in the Medical, Urban, & Veterinary Entomology section of the Entomological Society of America at their annual meeting. Read below for her abstract. Congratulations, Kaylee!

Kaylee’s study organism, the triatomine or kissing bug. Picture provided by Linda Tanner via Flickr (CC BY-NC-ND 2.0).

Chagas disease is caused by the parasite Trypanosoma cruzi that is carried in the guts of hematophagous triatomine vectors. Triatomines are often coinfected with the parasite T. rangeli, which is non-pathogenic to mammals but can reduce fitness of their triatomine hosts. This study examined the gut microbial diversity of T. cruzi infected, coinfected, and uninfected triatomines (n = 288) throughout central Panama. We hypothesized that single and coinfected triatomines would have greater gut microbial diversity than uninfected individuals due to pathogen-microbe interactions within the gut, which can facilitate the proliferation of less dominant bacterial taxa.

Coinfections were found in 13% of individuals (40/288) and there was significantly greater alpha diversity in coinfected individuals when compared to both single and uninfected samples (Dunn’s test of multiple comparisons, p < 0.001). Furthermore, single T. cruzi infections were found in 34% of sampled individuals (91/288) and also displayed significantly greater alpha diversity when compared to uninfected individuals (Kruskal-Wallis H test, p < 0.001). Across all samples, Sphingomonas was the most dominant taxa, and decreased in relative abundance compared to uninfected individuals. Finally, the beta diversity across infected samples was significantly different compared to uninfected samples (PERMANOVA p = 0.001 using Bray-Curtis dissimilarity). These results highlight patterns of microbial diversity which may be impacted by vector infection status and will be important to consider when developing vector control strategies.

Lexi Kenna defends Master’s Thesis!

Congratulations, Lexi! Here is the abstract of her thesis, entitled Invertebrate herbivory of understory trees in the Georgia Piedmont in response to soil warming:

As the global mean surface temperature increases, changes in biogeochemical cycling have the potential to have cascading effects on plant and invertebrate interactions. Previous warming studies have primarily been conducted in recently glaciated, more fertile soils, and the response of plant and invertebrate interactions to warming is unclear in lower latitude, less fertile soils of the Georgia Piedmont. In this study, I examined leaf and soil chemistry (%N, C:N) and herbivore damage (% leaf area consumed) from understory tree seedlings of the Georgia Piedmont. Carbon and nitrogen foliar content and invertebrate herbivory did not respond to warming in any year, but there were interactive effects of temperature and species. Overall, warming did not have an indirect effect on plant-herbivore interactions, which is likely due to Piedmont soils containing less available nitrogen. However, species-level variation in response to warming has implications for forest composition changes.