Efficacy of a Fungal Biopesticide for Bed Bug Management Is Influenced by the Toxicity and Associated Behavioral Avoidance of Harborages on Insecticide-Impregnated Box Spring Covers.

Abstract

Bed bugs spend most of their lives hiding in harborages, usually in the seams of mattresses and box springs and in crevices of bed frames. For insecticidal products that target these shelters, the repellency of the products for bed bugs may influence their duration of contact. Bed bugs are known to avoid contacting surfaces treated with certain insecticides. The fungal biopesticide Aprehend contains spores of the entomopathogen, Beauveria bassiana. It is sprayed around bed frames, box springs, and furniture where bed bugs are likely to walk, which includes potential shelters. Here, I investigated the influence of a permethrin-impregnated cover, ActiveGuard, on bed bug sheltering behavior and the effectiveness of combining ActiveGuard with Aprehend. Bed bugs avoided harboring in a shelter constructed with ActiveGuard compared to a nontoxic encasement-type cover. This avoidance behavior reduced mortality induced by ActiveGuard shelters compared to forced continuous contact on the ActiveGuard cover. However, while bed bugs also avoided Aprehend-treated ActiveGuard shelters, the combined treatment induced almost complete mortality and more quickly than Aprehend-treated shelters made of the encasement-type cover. This suggests compatibility between the two integrated pest management (IPM) tools even though the bed bug's avoidance behavior would suggest otherwise. Since Aprehend is highly effective against pyrethroid-resistant bed bugs, its use would provide more effective control where bed bug populations are more resistant to the permethrin-impregnated cover.