Warm weather sends mosquitoes biting in Georgia

By for CAES News

By Stephanie Schupska
University of Georgia

As spring temperatures waver before the summer heat hits Georgia, more people are cracking open their windows to catch a few cool breezes. And many are letting in mosquitoes.

University of Georgia entomology expert Elmer Gray says opening a window without checking to see if the screen has holes or is flush to the window frame is like inviting mosquitoes over for lunch.

“Right now we’re in this period where it’s nice to have the windows open, the transition from winter to summer,” Gray said. “Make sure your screens are tight and don’t have any holes in them. As the heat of the summer builds, most of us go to air conditioning, and it’s not as big as a factor. But certainly right now, when we’re in the transition period, keep your screens in good repair.”

Gray is an agricultural research coordinator in the entomology department of the UGA College of Agricultural and Environmental Sciences. He rejects the thought that a warmer winter will bring more mosquitoes.

“I’m not a big believer that the winter temperatures have a huge effect on the following year’s mosquito population,” he said.

He corrects the idea that a drier summer will keep the population down, too. He does say, however, that the mild winter may have allowed mosquito populations to develop earlier in the spring.

What is going to affect mosquito numbers, he said, is how much standing water the state accumulates in the spring and summer. That’s what really determines how many mosquitoes will develop, he said.

In 2004 and 2005, Georgia was swamped with hurricane rains. As a result of river flooding in the bottomlands, native mosquitoes had more places to breed.

While a dry summer will keep down some of the woodland and floodwater mosquitoes, it also causes more concerns late in the season, Gray said.

“The Southern house mosquito that transmits West Nile virus likes to breed in storm drains,” he said. “When we’re not having rain, when it gets dry, the storm drains become stagnant, and this mosquito is apt to develop in large numbers. And that’s a real concern for us.”

Georgia had 24 cases of West Nile virus in 2005. Two people died.

Heavy rains during the past two hurricane seasons kept this population of mosquitoes down. “Consequently, it’s probably helped contribute to the lower numbers of West Nile virus,” Gray said. “The West Nile virus is still around and is something we need to be concerned with.”

Hurricane flooding isn’t the only breeding ground for native mosquitoes. And neither are retention ponds. In fact, pests such as the black-and-white-striped Asian tiger mosquito typically fly only about 100 yards from where they develop.

If Georgia residents are finding many of these pests in their homes and yards during daylight hours, Gray said, “you or someone nearby is typically producing them.”

Asian tiger mosquitoes are container breeders.

“It’s so important that homeowners and communities take responsibility for their own mosquito problems and empty out standing water in containers and debris around their homes,” he said.

He gives other tips on keeping mosquitoes off:

• Wear light-fitting, loose, light-colored clothes. Mosquitoes are attracted to darker colors, as are most of the biting flies. The light-colored clothing will help reduce attractiveness.

• Use insect repellents properly, whether it contains the active ingredient DEET or the newly approved ingredient picaridin.

• Eliminate standing water. This is something that needs to be done year-round, not just in April and May.

“Mosquitoes will develop through most of the year here in Georgia,” Gray said. “Certainly, in the peak of winter it won’t be a significant problem. But any standing water, they’ll find it. And on warm days they’ll lay their eggs in there and will resume the cycle.”

(Stephanie Schupska is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)

Stephanie Schupska is a news editor with the University of Georgia Public Affairs Office.