Insecticidal gel bait formulations against the poultry litter beetle, Alphitobius diaperinus : integrating toxicological and behavioral analyses

Abstract BACKGROUND The poultry litter beetle, Alphitobius diaperinus , is an important pest of poultry production systems, yet commercial insecticidal gel baits have not been systematically evaluated for its management. We evaluated 10 gel bait formulations against adults from five beetle populations under no‐choice and food‐choice conditions (50 mg formulation per arena), assessing mortality over 14 days (336) h and short‐term bait related and post‐exposure responses in separate behavioral assays. RESULTS Emamectin benzoate and fipronil formulations generally produced the most rapid declines in survival, with LT 50 values commonly near or below 24 h, whereas abamectin B1 showed substantial but greater population‐ and feeding‐dependent variation. Boric acid produced slower, progressive mortality, while several neonicotinoid‐based formulations and indoxacarb produced slower, more variable, or incomplete mortality; for several baits in particular beetle populations, LT 50 was not reached within 336 h. Alternative food generally delayed mortality and increased variability in bait performance. During 8–10 h behavioral observations, imidacloprid produced more frequent behavioral signs of intoxication and knockdown, particularly in the Nash [NC] population (6/15 beetles reached knockdown), whereas only 1/15 boric acid‐exposed beetles in each population reached knockdown despite observed bait interaction. CONCLUSION Gel‐bait performance against adult A. diaperinus depends on formulation, population, and feeding context. Integrating mortality kinetics with behavioral observations showed that acute impairment does not necessarily predict longer‐term mortality. These findings identify promising bait formulations for field validation and potential incorporation into poultry integrated pest management programs. © 2026 Society of Chemical Industry.