Hungry Mosquitoes Target Active, Large People

MILWAUKEE —  Some people are more attractive targets for mosquito bites than others, a researcher says.

Active people, as well as larger folks and fidgety people with faster metabolisms, are more susceptible to getting bit, said Jonathan Day, a professor at the University of Florida’s Medical Entomology Lab.

Day has been studying mosquitoes and the diseases they carry since 1978.

People exhale more carbon dioxide when they are larger or more active. Mosquitoes sniff out carbon dioxide plumes to locate their targets from up to 18 feet away. The more carbon dioxide released, the easier the person is to locate.

As mosquitoes move in, they see movement, so active people stand out again, Day said. People wearing dark clothing also stand out because mosquitoes see color in terms of contrast with the light horizon.

But it isn’t until a mosquito lands on a person that body heat and chemistry get noticed, Day said. Active people again are at a disadvantage.

Mosquitoes use body heat to find the best spot to dine--the area with the most blood close to the surface, Day said. They also detect lactic acid on the skin and use it to identify their targets.

If a mosquito can’t detect lactic acid, it moves on to a more promising body, said Phil Pellitteri, insect diagnostician in the Department of Entomology at the University of Wisconsin-Milwaukee.

The most active mosquito repellent, a chemical called DEET, works because it blocks the insect’s ability to sense lactic acid, Pellitteri said.