Enterobacter sp., a symbiotic bacterium found in Hessian fly

Hessian fly harbor stable microbial communities in the gut, composed mainly of the members of the γ-proteobacteria. Among them, Enterobacter sp., isolated from Hessian fly larvae, is a major component. Sixty-three 16SrRNA sequences out of 350 belonged to genus Enterobacter. This bacterium was found in two biotypes tested (biotype GP and biotype L). It was also detected in all the field populations so far tested including populations from Riley, KS and Fannin, TX and Grayson, TX. Initial results indicate that Enterobacter sp. are transmitted from mother to the offspring. We also determined the population dynamics of Enterobacter sp. throughout the Hessian fly life cycle using real-time PCR. The bacterium was found to increase progressively through the three larval instars. It was at the peak during the pupal stage and fell sharply during the adult stage. The presence of Enterobacter sp. in different populations and throughout the life cycle of Hessian fly gives strong evidence that this bacterium has significant effect on Hessian fly physiology.