A plug-in mosquito repellent cut indoor Anopheles funestus by 63%.

Mosquitoes spread malaria, and communities need more ways to control them beyond standard tools. Researchers tested a device called SumiOne spatial emanator in test huts in western Kenya against wild Anopheles funestus mosquitoes. A spatial emanator is a passive device that releases an airborne chemical, here ten percent metofluthrin, into the surrounding air to keep mosquitoes away without spraying. The researchers set up three treated huts and three untreated control huts to see how the device changed mosquito behavior. It worked very well. The device cut indoor mosquito densities by 63% and cut total indoor and outdoor mosquito densities by 58%. It also caused 34% of mosquitoes to exit the treated huts, compared to just 2% exiting control huts. Finally, it stopped mosquitoes from biting, cutting feeding by 46%. These results show the device can serve as a helpful extra tool alongside bed nets and indoor sprays.

Why it matters

Malaria kills hundreds of thousands each year. Bed nets and indoor spraying work, but mosquitoes are developing resistance and sometimes bite outside or when people aren't protected. This study tested a new device that releases a repellent chemical into the air, significantly reducing mosquito numbers and bites even in rooms without nets. If widely available, it could give families an extra layer of protection, especially in areas where current tools aren't enough.

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