Compatibility of Beauveria bassiana Isolates with Insecticide Formulations Used in Colorado Potato Beetle (Coleoptera: Chrysomelidae) Control

Abstract

Six Beauveria bassiana (Bb) isolates and 13 insecticide formulations were examined to find compatible combinations for Leptinotarsa decemlineata (Say) management. Fcw significant differences were found between Bb isolates. Emulsifiable-concentrate insecticide formulations using xylene-based, aromatic solvents were most inhibitory toward Bb. Wettable-powder formulations often increased colony counts. Pyrethroids (permethrin and fenvalerate) were inhibitory as both formulated and technical materials. Most Bb inhibition occurred within 4 h of mixing. Separate application of Bb and insecticides greatly mitigated Bb inhibition.