Mosquitoes Detect Plant Repellent Through Specific Sensory Receptor

New research reveals Aedes aegypti mosquitoes use OR49 receptor to avoid borneol, a compound found in aromatic plants.

Mar. 17, 2026 at 3:24am

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New research by an international team, including researchers at the University of Washington, reveals that Aedes aegypti mosquitoes use a specific sensory receptor called OR49 to detect and avoid borneol, an organic compound found in several aromatic plants like camphor trees and rosemary. When mosquitoes encounter borneol, it activates OR49 and triggers avoidance behavior, providing a potential new avenue for developing more effective mosquito repellents.

Why it matters

Mosquito-borne diseases like dengue, malaria and Zika cause over 600,000 deaths worldwide per year. As mosquitoes become increasingly resistant to current insecticides, new methods to prevent mosquito bites and disease transmission are urgently needed. Understanding how mosquitoes detect and respond to plant-based repellents could lead to the development of more effective and environmentally-friendly mosquito control strategies.

The details

The researchers discovered that Aedes aegypti mosquitoes, the major carrier of dengue and yellow fever viruses, have a single odor receptor called OR49 that is highly sensitive to detecting the compound borneol. When a mosquito encounters borneol, it activates OR49 and triggers a signal that travels to a specific region of the mosquito's brain, causing the insect to avoid the repellent. Disabling the OR49 gene eliminated the mosquitoes' ability to detect and avoid borneol.

  • The study was published on February 20, 2026.

The players

Jeffrey Riffell

A UW professor of biology and co-author of the study.

Jason Pitts

An associate professor of biology at Baylor University and co-senior author of the study.

Carlos Ruiz

A UW postdoctoral scholar in the biology department and co-author of the paper.

Aedes aegypti

The mosquito species that is the major carrier of dengue and yellow fever viruses.

OR49

The odor receptor in Aedes aegypti mosquitoes that is highly sensitive to detecting the compound borneol.

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What they’re saying

“We were surprised by how sensitive the mosquitoes were to this repellent. By identifying the odorant receptor, we can now develop and test repellents that are even more effective than borneol, in that they last longer and are more repellent.”

— Jeffrey Riffell, UW professor of biology (Mirage News)

“Because the repellency through the OR49 receptor is so strong, we might be able to identify other volatile odors that activate the same receptor to 'push' mosquitoes away from people. The new compounds might be easier and cheaper to produce, or safer and more acceptable to the human nose than existing repellent formulations.”

— Jason Pitts, Associate professor of biology at Baylor University (Mirage News)

What’s next

The researchers plan to continue studying the genetic basis for how Aedes aegypti mosquitoes are attracted to sources of nectar, with the goal of creating new mosquito attractants that can be used in traps to enhance mosquito surveillance and control.

The takeaway

This research provides valuable insights into how mosquitoes detect and respond to plant-based repellents, offering new opportunities to develop more effective and environmentally-friendly mosquito control strategies to combat the spread of deadly mosquito-borne diseases.