Monday, December 10, 2007 - 8:29 AM

Gut microbial community anaylsis through the life history of the Asian longhorned beetle (Anoplophora glabripennis)

Scott Geib, and Kelli Hoover, Pennsylvania State University, Entomology, 501 ASI, Univerisity Park, PA

The Asian longhorned beetle (ALB; Anoplophora glabripennis, Family Cerambycidae) thrives in an inhospitable environment on an intractable energy source, the inner-wood of a wide variety of hardwood trees. Hardwoods are high in lignin and contain anti-microbial secondary metabolites. How this beetle is able to degrade wood is largely unknown. We hypothesize that gut community structure can change as the beetle goes through its lifecycle, allowing this insect to exploit multiple regions of the tree and a broad range of host tree species, contributing to its invasive behavior. In this study we characterized the ALB gut community as a function of life stage, determine the source of gut microbes as maternally derived or acquired through feeding on the host tree. To compare gut microbial communities among different developmental stages, we used B-ARISA (Bacterial- Automated Ribosomal Intergenic Spacer Analysis) combined with cloning and sequencing. This method allows rapid comparison of microbial diversity in many samples at one time. We found unique bacterial species in the woody tissue chewed by the female within the egg site and in eggs collected from host trees. The presence of microbes from these locations suggests bacterial species were transmitted by the mother to the egg. Other species of bacteria seem to be acquired from the host tree. Understanding how this insect is able to acquire and change its gut community will allow for better understanding of how it is able to feed on woody tissue.

Species 1: Coleoptera Cerambycidae Anoplophora glabripennis (Asian longhorned beetle)