Assessing the Potential for Soil-mediated Transmission of Symbiotic Bacteria in the Leaffooted Bug (Leptoglossus phyllopus)

Recent evidence suggests insects might indirectly provide symbionts to their offspring by releasing them into the soil via feces. We investigated whether this is occurring in the Eastern leaf-footed bug, Leptoglosuss phyllopus. We hypothesized that if adults release viable symbiont cells into their environment, then nymphs will have a higher survival rate, develop faster, and be larger at adulthood when exposed to soil that has been in contact with adult insects for longer. To measure the rate and whether the bugs acquired Caballeronia from the soil, insect nymphs were exposed to soil that had been exposed to a lab colony of L. phyllopus for different lengths of time. After exposing the nymphs to the colony soil, their development time, survival, and mass in adulthood were measured. Contrary to our hypothesis, we observed that nymph survival decreased as the length of time soil was exposed to the lab colony increased. We speculate that diseases carried by adult insects in the colony might have overwhelmed any possible positive effect of the adults inoculating soil with the symbiont. By studying this symbiosis within insect host species, we can improve our knowledge of the complexities of microorganisms and how they shape the physiology of their host and its community.