An avoidance behavior to wet surfaces by bed bugs (Hemiptera: Cimicidae)

Due to the global resurgence of bed bugs (Hemiptera: Cimicidae), various methods of bed bug control have been implemented. Chemical pesticides targeting bed bugs are often applied as an aqueous suspension or solution. This study aims to determine the behavioral response of bed bugs (Cimex lectularius L.) to wet surfaces. A circular arena was divided into two halves: a dry half and a wet half. The wet half was treated with varying amounts of deionized water, resulting in the following four treatments: no water (control), low, medium, or high surface densities of water. The lowest surface density of water used in the current study assumed the application rate approximately twice higher than typical application rates of common aqueous spray pesticide products (1 gal / 1,000 sq ft). Bed bugs were allowed to navigate freely within the arena for 10 min. Bed bugs of both sexes (adult) and all nymphal stages were observed to avoid wet surfaces. Bed bugs spent significantly less time and walked significantly shorter distances on wet surfaces. This result was amplified as the surface density of water increases. Furthermore, for the lowest surface density of water, adult velocity on wet surfaces was higher than that on dry surfaces. Biological and practical implications of this avoidance behavior will be discussed.