Occurrence of the Entomogenous Fungus Beauveria bassiana in Pecan Orchard Soils in Georgia

Abstract

Soils from 19 pecan orchards in ten Georgia counties were sampled for Beauveria bassiana (Balsamo) Vuillemin propagules utilizing a selective oatmeal-dodine agar. The 543 soil samples were collected at times corresponding to adult pecan weevil, Curculio caryae (Horn), emergence from the soil and larval penetration into the soil. Fungal propagules were detected in the soils of each of the 19 orchards on both sampling dates. Therefore, soils in pecan orchards in Georgia appear to contain B. bassiana propagules during periods of adult and larval activity of pecan weevils regardless of location, soil type, or pest management practices. Environmental conditions in these orchard soils are apparently conducive for B. bassiana stability and persistence and may enhance efforts to augment the natural inoculum.