A research team has identified a crucial odorant receptor in mosquitoes that detects borneol, a natural repellent compound, opening up new avenues for developing environmentally friendly methods for controlling mosquito populations. This significant finding was announced by the Hebrew University of Jerusalem.

The study, published in the journal Nature Communications, involved collaboration among researchers from China, Israel, the United States, and Sweden. The investigation revealed that the receptor, known as OR49, is highly conserved and is responsive to borneol, a compound derived from camphor tree oils.

When activated, OR49 triggers a neural pathway that overrides the mosquitoes' attraction to human scents, prompting them to move away from potential hosts. The vital role of this receptor was further confirmed when genetically disabled mosquitoes failed to avoid borneol.

OR49 was found to be operational in major disease-carrying mosquito species, such as Aedes aegypti, known for transmitting dengue and Zika viruses, as well as Culex mosquitoes responsible for the West Nile virus. Behavior tests demonstrated that mosquitoes exposed to borneol significantly reduced their proximity to human skin.

As resistance to traditional chemical repellents becomes a growing concern and as worries about their environmental and health impacts rise, understanding how mosquitoes detect repellents is becoming increasingly essential. The research highlights the potential for developing repellents that are more effective, longer-lasting, and safer for both humans and ecosystems.

Moreover, the findings link contemporary science to historical practices: materials rich in camphor and borneol were traded from Borneo into China via the Maritime Silk Road for their aromatic and insect-repelling properties. The newly identified OR49 pathway sheds light on the enduring effectiveness of these natural repellents.