@article{ashbrook_schwarz_schal_mikaelyan_2024, title={Lethal disruption of the bacterial gut community in Eastern subterranean termite caused by boric acid}, volume={10}, ISSN={["1938-291X"]}, url={https://doi.org/10.1093/jee/toae221}, DOI={10.1093/jee/toae221}, abstractNote={Abstract The Eastern subterranean termite, Reticulitermes flavipes (Kollar) (Blattodea: Rhinotermitidae), is a significant pest, causing extensive damage to structures that amount to substantial economic losses. Boric acid is widely used for wood preservation due to its stability and broad-spectrum insecticidal properties, yet its impact on termite gut microbiomes and the implications of such effects remain understudied. Our study evaluates the dose-dependent mortality of R. flavipes upon being provided boric acid treated filter papers and investigates the resulting dysbiosis within the termite gut microbiome. Consistent with reports from other insects, mortality increased in a dose-dependent manner, with the highest boric acid concentration (203.7 µg/cm2 of filter paper) significantly reducing termite survival. 16S rRNA gene sequencing of the gut bacterial microbiome revealed notable shifts in composition, indicating boric acid-induced dysbiosis. Aside from an overall decrease in bacterial diversity, the relative abundance of some symbionts essential for termite nutrition decreased in response to higher boric acid concentrations, while several opportunistic pathogens increased. Our findings extend the understanding of boric acid’s mode of action in termites, emphasizing its ability to significantly modulate the bacterial symbiont community, which can have dire effects on termite biology. Considering its ability to protect wood from further termite consumption, our study supports the continued use of boric acid and related compounds for termite-resistant treatments for wood.}, journal={JOURNAL OF ECONOMIC ENTOMOLOGY}, author={Ashbrook, Aaron R. and Schwarz, Melbert and Schal, Coby and Mikaelyan, Aram}, editor={Husseneder, ClaudiaEditor}, year={2024}, month={Oct} }
 @article{ashbrook_mikaelyan_schal_2022, title={Comparative Efficacy of a Fungal Entomopathogen with a Broad Host Range against Two Human-Associated Pests}, volume={13}, ISSN={["2075-4450"]}, url={https://doi.org/10.3390/insects13090774}, DOI={10.3390/insects13090774}, abstractNote={The ability of a fungal entomopathogen to infect an insect depends on a variety of factors, including strain, host, and environmental conditions. Similarly, an insect’s ability to prevent fungal infection is dependent on its biology, environment, and evolutionary history. Synanthropic pests have adapted to thrive in the indoor environment, yet they arose from divergent evolutionary lineages and occupy different feeding guilds. The hematophagous bed bug (Cimex lectularius) and omnivorous German cockroach (Blattella germanica) are highly successful indoors, but have evolved different physiological and behavioral adaptations to cope with the human-built environment, some of which also reduce the efficacy of fungal biopesticides. In order to gain greater insight into the host barriers that prevent or constrain fungal infection in bed bugs and German cockroaches, we tested different doses of Beauveria bassiana GHA through surface contact, topical application, feeding, and injection. Bed bugs were generally more susceptible to infection by B. bassiana with the mode of delivery having a significant impact on infectivity. The German cockroach was highly resilient to infection, requiring high doses of fungal conidia (>8.8 × 104) delivered by injection into the hemocoel to cause mortality. Mortality occurred much faster in both insect species after exposure to surfaces dusted with dry conidia than surfaces treated with conidia suspended in water or oil. These findings highlight the importance of developing innovative delivery techniques to enhance fungal entomopathogens against bed bugs and cockroaches.}, number={9}, journal={INSECTS}, author={Ashbrook, Aaron R. and Mikaelyan, Aram and Schal, Coby}, year={2022}, month={Sep} }
 @article{ashbrook_feder_scharf_bennett_gondhalekar_2021, title={Characterization of heat exposure-associated escape behaviors and HSP gene expression in bed bugs (Cimex lectularius L.)}, ISSN={["1526-4998"]}, DOI={10.1002/ps.6620}, abstractNote={AbstractBACKGROUNDHeat can be effective for bed bug elimination. However, in some cases bed bugs survive heat treatments. The objectives of this study were to determine the behavioral responses of bed bugs to rising harborage temperatures (23.0–49.0 °C) and identify which heat shock protein (HSP) genes are expressed after heat exposure. First, a custom‐made copper arena and harborage were used to determine the escape behaviors of six bed bug populations. Next, HSP gene expression responses of select populations were determined after heat exposure using real time quantitative polymerase chain reaction (RT‐qPCR).RESULTSAnalysis of the 25 min behavioral experiment data found that harborage top temperatures associated with 25%, 50% and 75% probabilities of bed bugs to flee the harborage did not differ significantly between populations. Also, the percentage of insects that escaped from heated areas and survived (4.0–12.0%) was not different between populations. However, when specific temperatures at which successful escapes occurred were statistically compared, the Poultry House population was found to flee the harborage at statistically higher temperatures (43.6 ± 0.5 °C) than others (40.5 ± 0.6–42.0 ± 0.7 °C). The RT‐qPCR experiments revealed that the HSP70.1, HSP70.3, and Putative Small HSP genes were significantly up‐regulated 15 min, 2, and 4 h post‐heat exposure and decreased back to baseline levels by 24 h.CONCLUSIONSThis study shows that when harborage top temperatures approach 40.0–43.0 °C, bed bugs will disperse in search for cooler areas. This work implicates the HSP70.1, HSP70.3, and Putative Small HSP genes in heat induced stress recovery of bed bugs. © 2021 Society of Chemical Industry.}, journal={PEST MANAGEMENT SCIENCE}, author={Ashbrook, Aaron R. and Feder, Jeffrey L. and Scharf, Michael E. and Bennett, Gary W. and Gondhalekar, Ameya D.}, year={2021}, month={Sep} }