Olfactory response of the antennal trichoid sensilla to human emanation and chemical repellents in the common bed bug, Cimex lectularius

The common bed bug Cimex lectularius, a temporary ectoparasite on humans, is currently resurgent in the developed countries. Similar to other haematophagous arthropods, host seeking and risk avoiding of the bed bug are partially mediated by olfaction. To gain insight into the bed bug’s olfactory response to semiochemicals from human emanation and insect chemical repellents, we, for the first time, investigated the interaction between the olfactory receptor neurons(ORNs) of the bed bug trichoid sensilla and 130 odors from human emanation and 45 insect chemical repellents. The results showed that different sensilla displayed distinctive response profiles to the semiochemicals. Aldehydes, the major components of human sweat, can elicit strong responses of the ORNs in a dose-dependent manner. The terpene-derived chemical repellents, which are important components of insect repellents, also displayed dose-dependent stimulations to ORNs of bud bugs. The bed bug showed a special response tendency to terpene-derived chemical repellents compared to non-terpene-derived chemicals, suggesting the potential of terpene-derived chemicals in the development of bed bug control repellents. Taken together, the current study not only elucidates the effects of human odors and chemical repellents on the bed bug olfactory system but also provides valuable information for screening new bed bug attractants and repellents.