Disruptions of mobility and foraging behavior of Alphitobius diaperinus adults exposed to sublethal insecticidal concentrations

Various pyrethroids and neonicotinoids have been evaluated against Alphitobius diaperinus. However, deltamethrin and a mixture of acetamiprid, d-tetramethrin, and piperonyl butoxide (d.a.p.) have never been examined for sublethal effects on A. diaperinus locomotion. Thus, the present study evaluated the impact of their LC₁₀ and LC₃₀ in the mobility traits of A. diaperinus adults (30 individuals/treatment), in the absence and presence of food source, after 8, 12, 24, and 48 h of exposure. Deltamethrin was more toxic compared to d.a.p. ANOVA revealed significant disruptions in locomotion, including increased immobility, reduced walking speed, and diminished climbing ability, especially with the LC₃₀ of deltamethrin, compared to the control group. The longest walking period was observed with the 12-h control group (609.5 s) vs. LC₁₀ and LC₃₀ of deltamethrin (235.3 and 300.2 s, respectively) and LC₁₀ and LC₃₀ of d.a.p. (456.1 and 481.7 s, respectively). Walking speed in the control groups was >46.0 mm/s while decreased to 7.9 and 8.8 mm/s after 48 h of exposure to the LC₃₀ of deltamethrin and d.a.p., respectively. Negative effects were noted for the mobility of A. diaperinus in the presence of food source. Control group individuals stayed in the food for >174 s while the insecticides-treated individuals for <86 s at 12, 24, and 48 h of exposure. Both insecticides negatively influenced the mobility behavior in the presence and absence of food source and the walking speed. These findings underscore the potential of considering sublethal concentrations of insecticides in integrated pest management strategies.