Development of mycoinsecticide formulations with Beauveria bassiana and Metarhizium anisopliae for the control of lesser mealworm, Alphitobius diaperinus, in chicken broiler houses

Abstract

Entomopathogenic fungi are promising alternatives to synthetic chemicals for controlling lesser mealworm populations in broiler houses. Granular formulations of two isolates of the fungi Beauveria bassiana and Metarhizium anisopliae based on ground chicken feed pellets produced 98 and 87% larval mortality, respectively, after 11 days’ exposure to ≈ 0.2 g conidia/54 g formulation m−2 in the laboratory. Oil based formulations with canola oil and Codacide™ were generally slower to produce mortality but still significantly effective. Granular formulations were effective on a range of broiler-house substrates (new and used litter, soil) of varying pH and moisture content. The efficacy of the M. anisopliae isolate appeared enhanced and the B. bassiana isolate inhibited on damp new litter (40% moisture). Substrate pH (3.45–6.38) did not discernibly inhibit fungal efficacy. Granular formulations of both fungal isolates tested at average broiler-house temperatures were ineffective at 35 °C but became active when re-tested at 30 °C. Granular mycoinsecticide formulations based on the two isolates are now ready for testing in commercial broiler houses.