Efficacy of Field-Isolated Strains of Beauveria bassiana (Moniliales: Moniliaceae) as Microbial Control Agents of the Lesser Mealworm (Coleoptera: Tenebrionidae)

Abstract

Two field isolates (NC2 and NC3) of Beuveria bassiana (Balsamo) Vuillemin were evaluated as microbial control agents of the lesser mealworm, Alphitobius diaperinus (Panzer), in a bioassay system incorporating physical characteristics of commercial poultry houses. Both isolates produced >90% mortality in new litter against larval A. diaperinus at the highest application rate (2.37 × 1011conidia per square meter) 2 wk after application. Neither isolate achieved as high a rate of mortality in used litter. Adult A. diaperinus were less susceptible than larvae to these isolates. At the highest application rate (2.37 × 1011conidia per square meter), isolate NC2 conidia achieved 60%mortality of adults in new litter and 33%mortality in old litter. The same concentration of isolate NC3 conidia produced 68 and 33% mortality in new and used litter, respectively.