Mosquito invasion likely to last two weeks, expert says

LANSING – If you've been slapping your arms and scratching your legs a lot lately you're not alone. The mosquitoes are bad this summer.

"This is one of our higher years for mosquitoes," said Linda Vail, Ingham County's health officer. "We've had a lot of wet weather."

There's really not much to be done with the pests except endure them — and avoid them as much as possible.

The Health Department's website urges residents to apply repellents during peak mosquito biting periods, such as dusk and dawn, and to drain standing water around their homes to remove mosquito breeding sites.

Mosquito repellent products containing federally approved active ingredients, such as DEET, picaridin, or oil of lemon eucalyptus are recommended, the department says.

Howard Russell, an entomologist for Michigan State University's Plant Soil and Microbial Sciences Department, says people also should wear loose fitting clothing, jeans and long-sleeve shirts when mosquitoes get busy. He also suggests tight-fitting doors and screens that are in good repair.

And then there's the use of a trusty fly-swatter for pests that get inside the house, Russell said.

Things weren't so bad a few weeks ago, he said. A dry March and April virtually eliminated the spring mosquitoes, which produce only one generation a year from eggs that lie dormant throughout the fall and winter.

However, the summer mosquitoes, which yield multiple generations, benefited from recent heavy rains.

"That brought on a whole new batch of mosquitoes that have been pretty awful," Russell said.

How long will they hang around? Russell says they'll be with us as long as there's plenty of standing water.

"My guess is there;s still larvae developing in that standing water," he said. "We're probably going to enjoy these mosquitoes for another 10 days or so, if not two weeks.

And if there's rain this week, it'll be longer.

About 60 species of mosquitoes call Michigan home, he said.

"There are a few species that we have that produce a generation every seven days or so if it stays above 80 (degrees)," Russell said. "So they're really bad now."

That's not unusual: "In general mosquitoes are horrible in Michigan," he said.

Last month, three nestling crows from Ingham County tested positive for the West Nile virus, which can cause serious illness such as meningitis and encephalitis, according to the state Department of Health & Human Services. Last year, 2,205 human cases of West Nile were reported nationwide and 97 people died, the Centers for Disease Control and Prevention said.

Contact Curt Smith at (517) 377-1226 or csmith@lsj.com. Follow him on Twitter @CurtSmithLSJ.