The objective of this work was to evaluate the interference of bioassay methods on the entomopathogenic fungi selection, using four Beauveria bassiana isolates and Alphitobius diaperinus adults. Regarding the inoculation form on insect mortality, the following methods were tested: insects immersion in a conidia suspension; spraying of a suspension over the insects; and surface treatment with eight concentrations. In order to evaluate the interference of immersion time on mortality, insects were immersed in a fungal suspension for 1, 10, 20, 30, 40, 50, and 60 seconds. Conidia produced on rice, insects, and synthetic medium were used to evaluate the influence of substrate on the virulence of the isolates. UNIOESTE 4 isolate and CG 152 were the most virulents for the methods immersion and spray, respectively; however, mortality was low in all isolates for the surface treatment. Mortality was proportional to the time during which insects stayed immersed, with a tendency to become stable after 40 seconds. Conidia from isolates CG 71 and CG 152 produced on insects were less virulent. The methods may influence bioassay results in the fungi selection for insects control.
Beauveria bassiana; Alphitobius diaperinus; biologic control; lesser mealworm; poultry houses
