Antennal olfactory sensilla responses to insect chemical repellents in the common bed bug, Cimex lectularius.

Populations of the common bed bug Cimex lectularius (Hemiptera; Cimicidae), a temporary ectoparasite on both humans and animals, have surged in many developed countries. Similar to other haematophagous arthropods, C. lectularius relies on its olfactory system to detect semiochemicals in the environment, including both attractants and repellents. To elucidate the olfactory responses of the common bed bug to commonly used insect chemical repellents, particularly haematophagous repellents, we investigated the neuronal responses of individual olfactory sensilla in C. lectularius' antennae to 52 insect chemical repellents, both synthetic and botanic. Different types of sensilla displayed highly distinctive response profiles. While C sensilla did not respond to any of the insect chemical repellents, Dγ sensilla proved to be the most sensitive in response to terpene-derived insect chemical repellents. Different chemical repellents elicited neuronal responses with differing temporal characteristics, and the responses of the olfactory sensilla to the insect chemical repellents were dose-dependent, with an olfactory response to the terpene-derived chemical repellent, but not to the non-terpene-derived chemical repellents. Overall, this study furnishes a comprehensive map of the olfactory response of bed bugs to commonly used insect chemical repellents, providing useful information for those developing new agents (attractants or repellents) for bed bug control.