Human Odorant Reception in the Common Bed Bug, Cimex lectularius

Human odorants are very important cues in the host-seeking process of the blood-feeding insects. For the common bed bug Cimex lectularius, a temporary ectoparasite on humans and currently resurgent in the developed countries, the host-seeking behavior is critical for them to survive and reproduce. Olfactory system of bed bugs plays an important role in detecting the human odorants in the environments. To gain insight into the interaction between the bed bug’s olfactory system and human odorants, we, for the first time, analytically investigated neuronal response of olfactory sensilla to a large panel of human odorants. The result showed that human odorants of different identity and intensity elicited neuronal response of olfactory sensilla with different firing frequencies and temporal dynamics. Particularly, aldehydes and amines were most distinctively differentiated in the odorant space of the bed bugs. Functionally characterization of bed bug odorant receptors and co-receptor in recognition to human odorants revealed molecular mechanisms involved in the olfactory responses to these human odorants and suggested the importance of aldehyde chemicals in the host-seeking process of bed bug. Taken together, our study on the interaction between the bed bug olfactory system and human odorants provide exciting insight into the odor coding mechanisms of bed bugs.