Light pollution may prolong mosquitoes’ biting season

Light pollution may prolong mosquitoes’ biting season

Global warming and a smaller electric bill aren’t the only reasons to turn off unneeded lights. That extra light might also disrupt mosquitoes’ winter dormancy and prolong their time to feast on human blood.

The findings by Ohio State University researchers could be considered a mixed bag. The good news is mosquitoes that can’t fatten up might not survive the winter. The bad news is that light pollution may keep them active later into the fall, meaning there’s more time for them to bite.

The results are among the first to show that artificial light triggers behavior changes in mosquitos. For Northern house mosquitoes, cold weather prompts a dormant period. They settle into caves, sheds and other protected locations. They also take a break from blood-sucking. As the days grow longer, the female mosquitoes again start foraging for blood.

The researchers established their findings by observing the insects’ feeding and activity in lab conditions with and without artificial light. At night, the artificial light consistently made them more active and likely to search for nutrients. That, the scientists said, may happen because artificial light disrupts the mosquitoes’ biological clocks.

And while a longer mosquito season is annoying to humans and other mammals who deal with the itchy effects of bites, it’s also potentially not good for the insects, either. Staying active later in the year may keep mosquitoes from doing the things they need to survive dormancy. That, in turn, could cull their numbers over the winter.

So, don’t be surprised if you find yourself scratching later in the year. And think about turning off that porch light.

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