Scientists decode how borneol repels mosquitoes — and it could transform pest control
Researchers identified the specific sensory receptor that makes borneol, a plant compound used in repellents for centuries, effective against disease-carrying mosquitoes. The discovery of this dedicated neural pathway opens the door to designing more potent repellents and could reshape the multi-billion dollar insect control industry.
Originaltitel: Sensory coding of borneol repellency in culicine mosquitoes via the Or49 pathway
Plant-derived repellents containing borneol and camphor have been used for centuries, yet the sensory mechanisms that mediate their effects in mosquitoes have remained obscure. Here, we show that culicine mosquitoes possess a dedicated olfactory pathway for detecting bicyclic monoterpenoids. We identify odorant receptor 49 (OR49) as a conserved and highly selective borneol receptor expressed in a distinct neuron of the maxillary palp. This neuron forms a defined projection to the MD3 glomerulus in the antennal lobe, establishing a labeled line for plant-derived repellents. Genetic disruption of Or49 abolishes electrophysiological responses to borneol and markedly diminishes avoidance behavior during human host-seeking. These results reveal that female mosquitoes detect borneol through a specialized sensory channel distinct from those mediating attraction to human cues. Our findings provide a mechanistic framework for understanding how plant volatiles shape mosquito behavior and offer a foundation for the rational design of next-generation olfactory repellents. Borneol has repelled mosquitoes for millennia, but how it worked was unknown. Here, the authors show the sensory pathway mosquitoes use to detect and avoid this ancient plant compound, opening the door to improved natural repellents.