Study: Light pollution may increase nighttime biting in mosquitoes

As if worsening light pollution weren’t enough, a new study shows the possible impact it’s having on the habits of a species of mosquitoes.

The rates at which the Aedes aegypti mosquitoes bite at night may have increased, according to research from the University of Notre Dame that was published in the American Journal of Tropical Medicine and Hygiene last week.

The insects usually fly and bite early in the morning and in the afternoon. But their changing habit places a spotlight on the concern that growing levels of light pollution could affect the transmission of Zika, chikungunya, yellow fever and other diseases, according to a news release from Notre Dame.

“This is potentially a very valid problem that shouldn’t be overlooked,” said Giles Duffield, associate professor in the Department of Biological Sciences.

Aedes aegypti are not like other species that may come from the forest to feed on humans and animals. They evolved with humans, and their preference is to feed on us.

“They live and breed in the vicinity of houses, so the chances of Aedes aegypti being exposed to light pollution are very likely,” said Duffield, who is also affiliated with the Eck Institute for Global Health and the Neuroscience and Behavior Program.

For the experiment, lead author and staff scientist in the Department of Biological Sciences Samuel S. C. Rund allowed mosquitoes in cages to bite his arms under controlled conditions, including blood-feeding in the daytime, nighttime or nighttime under exposure to artificial light. When exposed to artificial light at night, the female mosquitoes, which are the only ones to blood-feed, were twice as likely to bite. The control group had no light and 29% of them bit at night. Meanwhile, 59% of mosquitoes exposed to the artificial light bit.

Results from the study will aid in giving epidemiologists a better understanding of the real risk of disease transmission by Aedes aegypti. It’s possible that it will also spur more recommendations for the use of bed nets, which provide barrier protection against mosquitoes.

“The impact of this research could be huge, and it probably has been overlooked,” Duffield said. “Epidemiologists may want to take light pollution into account when predicting infection rates.”

For more information on the study, including how researchers plan to experiment with other variables, see the complete study here.