Submitted to: Society for Invertebrate Pathology Annual Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/15/2003
Publication Date: 8/15/2003
Citation: CASTRILLO, L.A., GRODEN, E., ANNIS, S.L., VANDENBERG, J.D. RISK ASSESSMENT OF USING MYCOINSECTICIDES: PREVALENCE OF A COMMERCIAL BEAUVERIA BASSIANA STRAIN AND ITS IMPACT ON CONSPECIFIC INDIGENOUS POPULATIONS. PROCEEDINGS OF THE ANNUAL MEETING OF THE SOCIETY FOR INVERTEBRATE PATHOLOGY. 2003. v. 36. p. 103.
Technical Abstract: The fungal pathogen Beauveria bassiana is widely used as a mycoinsecticide for control of several insect pests, providing a biological alternative to chemical insecticides. To date, no information is available on the impact of a mass-released fungal entomopathogen on conspecific indigenous populations in agricultural fields. In this study we compared prevalence of and genetic diversity within indigenous populations of B. bassiana in fields with no history of treatment with a commercial mycoinsecticide (strain GHA) and in fields representing a range of GHA application histories. Soil core samples from Maine and New York were sampled and plated on semi-selective medium for B. bassiana. Single spore isolates were established from representative colony forming units and isolate colony morphology was used initially to assess diversity. Then, assays were done with sequence-characterized amplified region markers to detect presence of GHA and with random amplified polymorphic DNA and amplified fragment-length polymorphisms markers to assess genetic diversity among indigenous isolates. Preliminary data suggest the persistence of GHA in Maine sites with multiple treatments, whether continuously for the last 9 years or 5 years after the last GHA application. Strain GHA was also found to be the predominant isolate in these fields, with only a few indigenous strains present. In contrast, soil samples from an organic farm in New York, never treated with GHA, revealed a diverse array of B. bassiana isolates.