Lethal and sublethal effects of three dust products on the tropical bed bug, Cimex hemipterus (Hemiptera: Cimicidae)

Desiccant dusts have been shown to be effective materials in the management of bed bugs (Cimex spp.). Past research primarily focused on exploring the direct lethal effect of dusts against bed bugs, whereas information on their sublethal effects on bed bugs are limited. In this study, we evaluated the lethal effect of 3 dust products (Johnson's^® Baby powder, Vazor DE powder^™, and CimeXa™; abbreviated as Baby powder, DE, and CimeXa) against the tropical bed bug, Cimex hemipterus (F.), under laboratory conditions. Results showed that the 3 dust products caused 97%-100% mortality to tropical bed bugs within 14 d, both in no-choice and choice experiments. However, in a brief exposure experiment (crossing a 2.5-cm-wide band), Baby powder exposure caused a significantly lower mortality (23%) than DE (88%) and CimeXa (100%). The more effective dusts (DE and CimeXa) were selected for further evaluation of their sublethal effects on C. hemipterus. DE and CimeXa caused significantly higher mortality (48%-58%) through horizontal transfer than that of control (6%). Brief exposure to DE and CimeXa dusts did not affect tropical bed bug activity and their response to CO₂. However, CimeXa-exposed tropical bed bugs exhibited reduced feeding and lowered survival rate after feeding. Moreover, both DE and CimeXa dust bands showed strong barrier effects on the crawling of tropical bed bugs. Our results indicate that both DE and CimeXa have great potential for preventing C. hemipterus from reaching protected areas and for controlling C. hemipterus.