Immediate and delayed mortality of different Alphitobius diaperinus developmental stages on chlorfenapyr-treated concrete

Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae) is a harmful species in storages, threatening the safety of poultry facilities since acts as a vector of noxious microorganisms for animals and humans. This laboratory study examines mortality levels of adults and larvae (small and large) of A. diaperinus on concrete surfaces sprayed with the half label or label dose of chlorfenapyr. Each developmental stage was exposed on concrete, either food was present or absent to assess their immediate and delayed mortalities. Concerning the immediate mortality, 97.8% of adults exposed on concrete sprayed with the label dose in the absence of food were killed after 7 days. However at the same exposure interval, only 32.2% of adults were killed on concrete sprayed with half label dose of chlorfenapyr, when food was present. Small larvae on concrete sprayed with label dose in the absence of food were all dead after 1 day of exposure. All the other dose and food scenarios achieved 100.0% mortality 3 days after initial exposure. All large A. diaperinus larvae died at all the tested dose and food scenarios 3 days after initial exposure. Adults exposed on concrete treated with label dose of chlorfenapyr reached 36.7 (with food) and 100.0% (without food) delayed mortalities. Half label dose caused 35.9 and 80.0% delayed mortality to adults with and without food respectively. Chlorfenapyr is an effective active ingredient (a. i.), able to cause elevated immediate and delayed mortality levels to A. diaperinus, regardless developmental stage, size and/or presence or absence of food when applied on concrete.

Automated summary

A laboratory study showed that spraying concrete surfaces with half label or label dose of chlorfenapyr greatly increased the mortality rates of Alphitobius diaperinus, a harmful species in storages. Regardless of the developmental stage, size, and the presence or absence of food, chlorfenapyr was found to be an effective active ingredient in causing immediate and delayed mortality to A. diaperinus.