Bright Light Repels Mosquitos, Reduces Bites


Mosquito repellent has always been something of a necessity, especially in parts of the world where malaria is a real and present danger. Chemical products and treatments are the most often used, but a new method of bug repellent utilizes something so simple and accessible, that it is almost too easy.

A recent study published in the journal Parasites and Vectors reveals findings that light can be used to manipulate mosquitos.

Credit: Antonio Correa/Flickr, CC BY 2.0

Exposure to light at night is unhealthy for humans, and mosquitoes do not seem to enjoy it very much either. After 10 minutes of light exposure at night, mosquito bites were far lessened and the flight patterns of the insects were altered as well. Egg-laying, feeding and flying are time-specific for mosquitoes, and as their behavior changed, their propensity for feeding changed as well.

Batches of mosquitoes were kept in the dark, then exposed to bursts of bright white light for a 10-minute period. Immediately after the pulse and every two hours following, the researchers tested the propensity of the mosquitoes for biting. The researchers held their arms against a mesh lining and allowed the mosquitoes to bite them, recording the results and analyzing the number of bites after the light treatment.

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Following the pulses of light, the mosquitoes were far less likely to feed during the testing times. Furthermore, the findings showed that if mosquitoes were pulsed with the white light every two hours, there was an even more significant reduction in biting.

“Most remarkable is the prolonged effect a short light treatment has on their preference to bite, with suppression lasting as long as four hours after the pulse,” said Giles Duffield, associate professor at the University of Notre Dame. “This may prove to be an effective tool that complements established control methods used to reduce disease transmission.”

As traditional repellents are losing their effectiveness, it has become necessary to explore other options. Duffield saw the need here for a mosquito repellent that the insects could not adapt to or find their way around.

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“We need to discover new methods to address mosquito control and prevention. The systems and tools we currently have, including global distribution and usage of insecticide-treated bed nets and spraying, are not enough,” he said.

To prevent mosquitoes from adapting to this type of repellent, Duffield and his team recommend exposing the mosquitoes to intermittent bursts of light, rather than constant exposure. They continue to research the effects of light exposure on mosquitoes using different types of light and different wavelengths.