Submitted to: Entomological Society of America Annual Meeting
Publication Type: Abstract only
Publication Acceptance Date: 10/1/2002
Publication Date: 11/19/2002
Citation: JARONSKI, S., CHERNYSH, A.V., SCHELL, S.P., LOCKWOOD, J.A. ENHANCEMENT OF BEAUVERIA BASSIANA AGAINST GRASSHOPPERS WITH VEGETABLE OIL CARRIERS. ENTOMOLOGICAL SOCIETY OF AMERICA ANNUAL MEETING. 2002. ABSTRACT #D0373. Interpretive Summary: We discovered in a series of lab, greenhouse and field experiments that canola oil can enhance the efficacy of the insect pathogenic fungus, Beauveria bassiana Strain GHA against grasshoppers because of its attractancy to the insects. When applied to rangeland in an approach whereby 100-foot-wide treated strips were alternated with 100-foot-wide untreated zones (50% coverage of a protected acre), the Beauveria fungus in canola oil outperformed itself when in a paraffinic oil, applied broadcast (100% coverage). These data indicate that use rates of the commercial fungus can be reduced certainly by 50% and obtain excellent efficacy when canola or similar oil is used as a carrier.
Technical Abstract: Beauveria bassiana is registered in the U.S. for control of grasshoppers, but efficacious use rates and product costs have been serious deterrents of adoption. Canola and certain other vegetable oils contain the fatty acids that stimulate necrophily and necrophagy in grasshoppers. Using these oils as ¿kairomonal¿ carriers or liquid baits can enhance chemical insecticide efficacy in a Reduced Agent Area Treatment System (RAATS) thus decreasing the amount of active ingredient per hectare by 50-80%. Our laboratory and greenhouse trials have shown that canola and corn oil have the potential to also enhance Beauveria efficacy for Melanoplus sanguinipes and M. bivittatus in a strip treatment approach through the attractant and/or phagostimulatory properties of the oils. Thus, use rates and cost per hectare for the mycoinsecticide may be reduced to more economically competitive levels. We also report the results of a field trial conducted in summer of 2002 combining these oil carriers and RAATS against Aulocara elliotti and Cordillacris occipitalis populations in Wyoming.