Litter Beetle (Alphitobius diaperinus) movement on a poultry farm and in a laboratory

Abstract

Abstract

Litter beetles (Alphitobius diaperinus) are significant pests in commercial poultry operations, acting as reservoirs for avian pathogens and causing damage to building structures. As chemical control measures are diminished due to insecticide resistance, this study investigated the dispersal patterns, habitat preferences, and population dynamics of A. diaperinus in commercial broiler houses. The aim was to investigate how infestations spread to obtain information for the potential use of Sterile Insect Technique (SIT). A year-long monitoring of traps at the Auburn University Charles Miller poultry research farm across four houses, in conjunction with a paint-marking trial, dispersion assays, two mark-release-recapture (MRR) experiments, and both laboratory and field litter attraction assays, yielded comprehensive insights. The poultry farmhouse 2 at the Charles Miller poultry research farm exhibited the highest infestation level, with an average of 37.2 ± 2.79 SE beetles per trap per week (χ² = 189.83, df = 4, P < 0.001) and was selected for MRR studies. Five paint colors were tested for their suitability in the MRR experiments. Apple Red Satin enamel resulted in the least mortality and was chosen for marking the beetles. In a laboratory trial, beetle movement was found to be density dependent; in 10 minutes, a cohort of 30 beetles dispersed an average of 60.0 cm, while a cohort of 10 beetles dispersed only 18.8 cm (P < 0.001). In two MRR trials, approximately 2,500 and 5,000 marked adults were released and recaptured weekly over four weeks across 20 traps. In the smaller trial, 292 marked beetles were recaptured; marked catches declined numerically from Week 1 to Week 4 but not significantly (Kruskal–Wallis, P = 0.12). In the larger trial, 667 were recaptured, and the proportion of marked beetles in the catch declined significantly across weeks (P = 0.018), with Weeks 1 and 4 differing after Benjamini–Hochberg correction. In both trials, recaptured beetles were distributed unevenly among traps every week (χ² goodness-of-fit, all P < 0.001), indicating that beetles progressively redistributed across the house rather than remaining localized near the release point. In four choice assays conducted in the laboratory, there was no initial substrate preference observed (χ² = 1.04, df = 3, P = 0.792). However, in field studies, aged litter became a strong and increasingly attractive factor over time, with an average of 12.9 ± 1.71 beetles per trap compared to just 1.65 ± 0.32 for the control group. The attraction to aged litter increased from 7.2 to 24.0 beetles over four weeks (linear mixed model, P < 0.001). These findings provide essential estimates of beetle density, dispersal behaviour, and attraction, and offer a foundation for developing sustainable management methods for A. diaperinus. Keywords: dispersal, mark, release, recapture, Sterile Insect Technique, litter attraction, Alphitobius diaperinus, broiler houses.