Submitted to: Society for Invertebrate Pathology Annual Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 8/15/2003
Publication Date: 8/15/2003
Citation: FILOTAS, M., CASTRILLO, L.A., WRAIGHT, S.P., VANDENBERG, J.D., SANDERSON, J. MOLECULAR CHARACTERIZATION AND COMPARATIVE VIRULENCE OF BEAUVERIA BASSIANA ISOLATES FOR CONTROL OF THE SHORE FLY, SCATELLA STAGNALIS, ON GREENHOUSE CROPS. PROCEEDINGS OF THE ANNUAL MEETING OF THE SOCIETY FOR INVERTEBRATE PATHOLOGY. 2003. v. 36. p. 50.
Technical Abstract: The shore fly, Scatella stagnalis, occurs in large numbers in commercial greenhouses, where it is both a nuisance pest and a vector of plant pathogens. High populations can be difficult to suppress with chemicals, and there are no biological control products currently registered for use against S. stagnalis in the U.S. Reports of natural epizootics of the insect pathogenic fungus Beauveria bassiana in greenhouse populations and laboratory colonies of S. stagnalis suggest potential for biological control. We conducted studies to assess the diversity of B. bassiana isolates found naturally associated with a colony of shore flies established from a hydroponic lettuce production facility, and to compare these isolates to commercially available B. bassiana products. RAPD-PCR was used to assess genetic variation of B. bassiana isolates from S. stagnalis adults and pupae, and adults of Hexacola neoscatellae, a hymenopteran parasitoid of the shore fly. Sixteen single spore isolates were resolved into three distinct genotypes using 12 primers. Two of the most common genotypes were similar to ARSEF 252 and 5813, isolated from laboratory colonies of the Colorado potato beetle in Maine and Michigan, respectively. The third genotype was observed in only one isolate from a shorefly pupa. None of the genotypes was similar to B. bassiana strain GHA, the basis for BotaniGard, a mycoinsecticide registered in the U.S. for control of greenhouse pests. Further genetic analyses are planned for B. bassiana isolates obtained from the algal food source of these insects to ascertain whether this could be a natural reservoir for fungal inocula. Bioassays are currently underway to assess virulence of the three genotypes to all life stages of S. stagnalis and to compare this to that of commercially-available isolates of B. bassiana.