GAINESVILLE---If you think mosquitoes like you better than they like other people, you're probably right, say University of Florida researchers.
In a study to determine whether the tiny vampires choose their victims or feed indiscriminately, UF entomologist Jerry Butler and research assistant Karen McKenzie found that mosquitoes do, indeed, choose.
"Undoubtedly, mosquitoes have preferences," Butler said. "People do differ, and in any group of 10, one person will be fed on more than others."
Mosquitoes have evolved and survived -- even thrived, Butler points out -- because of their ability to choose the best hosts for their blood meals, which they need to lay eggs. They find their hosts, initially, through a keen sense of smell.
All people have to do to attract mosquitoes from even 40 miles away is breathe. As they exhale, their carbon dioxide and other odors mix to produce a plume that travels through the airstream. The plume acts like a dinner bell to mosquitoes, letting them know a warm-blooded meal is within range.
They fly up the plume in zigzag fashion until they arrive, for example, at a backyard cookout. Then they localize on eddies of other odors in the airstream and then, within yards of a person, they use vision and heat sensing to make a selection.
"Mosquitoes use odor to sort attractive people from the unattractive people to find those that are most tasty," said Butler, with UF's Institute of Food and Agricultural Science. "They are looking for the highest rates of human attractants."
What are those attractants? That's the next challenge for Butler and McKenzie. Already they know that natural excretions through the skin and skin-care products affect mosquitoes' appetite.
Take perspiration. By itself, it appears to be neutral, but as it ages bacteria begin developing, and that makes perspiration into a very strong attractant, Butler said. Bathing helps, but some after-bath products don't.
"The things you put on your
Contact: Jerry Butler
University of Florida