Optimisation of mycopesticides for control of lesser mealworm in broiler sheds

Lesser mealworm, Alphitobius diaperinus, is a ubiquitous insect pest of Australian meat-chicken sheds. It transmits a variety of avian pathogens and damages shed floors and insulation. Insecticide treatments to the shed floors and lower-walls before flock placement is the usual management practice for lesser mealworm, but insecticide resistance development has compromised their efficacy.

Recently, Agrifutures Australia invested in a project (PRJ-010321) that delivered a proof of concept for mycopesticide control of lesser mealworm in meat-chicken sheds. Granular formulations of two different entomopathogenic fungi, Beauveria bassiana and Metarhizium anisopliae, were successfully trialled at a chicken farm in southeast Queensland. Applications of the formulations to the earth-floor along walls and under feed supply lines produced mean suppressions in lesser mealworm populations of 72% for the Beauveria formulation and 50% for the Metarhizium formulation, compared to untreated populations. Comparative suppression by an industry insecticide regime was 49%.

Further work is now needed for a mycopesticide to be industry-ready. In this project, field trials with the best granular formulation (Beauveria) will be undertaken in meat-chicken sheds with litter-reuse systems and hard floors, with variations in spatial application (eg brooder-only treatment). In addition, a liquid formulation of the Beauveria mycopesticide would be evaluated for treatment diversity. Trials would extend to the wintertime when lesser mealworm numbers are lower and fungal efficacy potentially greater. In addition, co-application of industry insecticides and mycopesticides will be investigated. These trials would optimise the mycopesticides for lesser mealworm control and generate the data needed for commercial uptake.