Effect of feeding status on mortality response of adult bed bugs (Hemiptera: Cimicidae) to some insecticide products.

Fresh and aged residual deposits of several insecticide products were tested against bed bug adults to determine if a recent bloodmeal affected their mortality response to the residues. The bed bugs with a recent bloodmeal survived significantly longer compared with the unfed ones on their exposure to fresh or aged residual deposits of chlorfenapyr and aged residual deposits of deltamethrin on a wooden substrate. Even though the survival time of fed bed bugs was significantly longer than that of unfed ones on their exposure to fresh residue of deltamethrin and aged residue of desiccant pyrethrin dust, these treatments resulted in similarly high final mortalities regardless of feeding status of the insects. Mortality responses of fed and unfed bed bugs were similar to fresh or aged residual deposits of imidacloprid + cyfluthrin combination and fresh residual deposits of desiccant pyrethrin dust. Topical application assays indicated that a recent bloodmeal significantly increased the bed bug's survival time for chlorfenapyr, but not for deltamethrin. Pyrethroid-resistant bed bugs also showed a similar increase in their survival time for chlorfenapyr after a bloodmeal. The comparison of mortality responses between fed and unfed bed bugs treated with similar amount of chlorfenapyr per fresh body weight indicated that increased body mass was not the primary cause for this bloodmeal-induced tolerance increase for chlorfenapyr. Because the surviving bed bugs can continue ovipositing, the effectiveness of chlorfenapyr residual deposits in bed bug harborages could be significantly affected by the feeding status of the adult bed bug populations.