Strategic positioning of Beauveria bassiana sensu lato JEF-410 in management of poultry red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae)

The red mite, Dermanyssus gallinae (Mesostigmata: Dermanyssidae), is one of the most serious pests in chicken farming and causes serious economic losses. Overuse of chemical acaricides has caused pest resistance as well as environmental residual toxicity to chickens and eggs. Therefore, given the warm and humid conditions of chicken farms, alternative application with entomopathogenic Beauveria bassiana sensu lato was investigated to control D. gallinae. Based on the characterization and virulence assays of B. bassiana isolates against red mite, a red mite-pathogenic fungal library was constructed. A total of six highly virulent B. bassiana isolates were selected from the first bioassay. They showed 70–100% mortality in ten days which were higher than cypermethrin, showing 40% mortality. Considering their fungal virulence, conidial production, and thermotolerance, isolate JEF-410 was established to be the best candidate for industrialization. JEF-410 showed a dose-dependent virulence against red mite nymphs. JEF-410 conidia from millet granule-based mass culture were applied to a commercial chicken farm and it showed a significant suppression of population increase under high humidity conditions. In summary, B. bassiana JEF-410 having higher control efficacy than cypermethrin could be effectively used to control D. gallinae in the fungus-friendly humid chicken farms. This work solved challenges of mass production of B. bassiana and management of the red mite in poultry farming under right conditions of RH and temperature.