Biological Activity of Bacillus thuringiensis and Associated Toxins against the Asian Longhorned Beetle (Coleoptera: Cerambycidae)

Abstract

Bacillus thuringiensis Berliner var. tenebrionis and B. thuringiensis toxins were assayed against larval and adult Asian longhorned beetles, Anoplophora glabripennis (A. glabripennis). Preliminary in vitro assays showed some toxins to be active on whole midgut preparations in voltage clamp assays and in assays on brush border membrane vesicles formed from midgut epithelial cells. For in vivo tests, a commercially-available product (Novodor®) was incorporated into artificial diet, upon which larvae were allowed to feed ad lib. In other tests, droplets of solubilized B. thuringiensis toxins were fed to larval and adult beetles using a micropipette. None of the in vivo assays showed significant negative effects on either larvae or adults. We believe that some aspect of A. glabripennis midgut chemistry may be incompatible with toxin activation or mode of action.