Mycoinsecticide formulations of Beauveria bassiana and Metarhizium anisopliae reduce populations of lesser mealworm, Alphitobius diaperinus, in chicken-broiler houses

Abstract

Granular formulations of two entomopathogenic fungal isolates of Beauveria bassiana and Metarhizium anisopliae were evaluated as mycoinsecticides for control of lesser mealworm populations in broiler houses at a farm in southeast Queensland, Australia, over five production batches. The formulations were compared to rotated treatments of the insecticides β-cyfluthrin and spinosad, and to untreated populations. Lesser mealworm populations were measured by counting insects in bedding litter samples taken from under feed pans each week of each batch. Granular formulations applied at ≈45 g/m2 (conidia per m2: 3.4 × 1010B. bassiana; 1.28 × 1010M. anisopliae) in 0.9 m-wide bands under feedlines and along walls each batch produced mean population suppressions of 72% for B. bassiana and ≈50% for M. anisopliae, compared to untreated populations. The insecticide regimen applied at label rates to the whole floor and lower walls of houses each batch produced a mean suppression of ≈48%. An application of the fungicide imazalil for Aspergillus in batch 4 appeared to inhibit the efficacy of the mycoinsecticide formulations.