Evaluation of Resistance to Different Insecticides and Metabolic Detoxification Mechanism by Use of Synergist in the Common Bed Bug (Heteroptera: Cimicidae)

Bed bugs have become a common urban pest with consequences on human health and economic costs to the hotel and tourism sectors. Insecticide resistance is considered an important factor in the current bed bug resurgence, and multiple resistance mechanisms could be working in the resistant bed bug populations. In the present study, we determined the resistance profile to four insecticides with a different mode of action in Cimex lectularius L. (Heteroptera: Cimicidae) field-collected colonies from Argentina. Furthermore, the synergism effect of piperonyl butoxide (PBO) with deltamethrin was investigated to explore the contribution of detoxification metabolism to resistance. Our results showed that most of the field-collected colonies are extremely resistant to deltamethrin and propoxur, much more than to azametiphos and imidacloprid. The differences in resistance ratios among field-collected colonies could be associated with different modes of action of insecticides used in control pest and the mechanisms involved in the resistance. PBO pretreatment led to a significantly decreased RR in pyrethroid-resistant colonies, suggesting an upturn of monooxygenase activity for deltamethrin detoxification. However, the high RR detected could involve other mechanisms as part of the whole resistant phenotype in colonies of C. lectularius resistant to pyrethroids.