Published on 05/07/09

Protect yourself from mosquito baby boom

By April Sorrow
University of Georgia

Georgia’s drought kept mosquitoes, to a point, at bay. But an abundance of rain and warm weather has sparked dormant eggs to hatch. By the millions, adult mosquitoes are descending on Georgians all across the state.

“As long as these mosquitoes keep laying eggs the problem will continue,” said Elmer Gray, an entomologist with the University of Georgia College of Agricultural and Environmental Sciences.

Georgia is home to 63 mosquito species. To control them in general, people can eliminate standing water and spray pesticides.

In south Georgia, though, more than just dumping containers is needed. There, mosquitoes come from riverbeds and swamps where eggs have been dormant through the drought. They are now immersed in water and hatching in record numbers, he said. Integrated pest management practices are needed, but these practices require resources, people and training.

“This is a good time for citizen groups to approach local government and request mosquito control programs,” Gray said. “In December, it won’t seem like a priority.”

Johnny Whiddon, UGA Cooperative Extension coordinator in Brooks County, said he is getting twice as many mosquito calls as last year. The southern county has many lowland areas. After receiving 19 inches of rain this spring, the areas are flooded, and mosquitoes are reproducing.

“We are applying for federal assistance to pay for spraying,” Whiddon said. “In the past, we couldn’t afford a spraying program, but now we need to figure out what we can do.”

To implement a mosquito control program, the county will need to set traps and record mosquito numbers. In the mean time, Whiddon tells citizens to treat flooded areas with larvaecide donuts and spray shrubbery around their homes with pesticides every 10 to 14 days.

Lowndes County has recorded over an 8,000 percent increase in mosquitoes in surveillance traps over a three-week period beginning April 6. The county has implemented a governmentally-funded program to assist in limiting these numbers, said Jake Price, Lowndes County extension agent.

Limit Exposure

Mosquitoes are most active at dawn and dusk. Limiting exposure during peak times is recommended. This isn’t the time to experiment with unproven repellents like eating garlic or using bug zappers, Gray said.

Most homeowners can’t do much to control mosquito breeding in wild areas, but they can limit them around the house by diligently getting rid of places where the larvae develop, like the water in toys, tarps, boats or buckets.

They can also:

• Secure window screens.

• Keep vegetation trimmed.

• Use barrier sprays on plants and entryways.

• Use burgess foggers.

Wearing light-colored, loose-fitting clothing helps. Mosquitoes are attracted to dark clothing and the human silhouette and sense body heat, which helps them locate blood – their food.

The most effective technique for preventing mosquito bites is the proper use of insect repellents, Gray said. He recommends products containing DEET. A product with a 10 percent to 30 percent concentration is good and protects for a few hours.

The Centers for Disease Control and Prevention and American Academy of Pediatrics also approved these strengths for children over two months old.

“Products containing DEET are still the best choice for young children,” Gray said. “When treating children, an adult should apply the repellent to his or her hands first and then rub the repellent onto the child’s exposed skin, but never to a child’s hands.”

Farm ponds, usually stocked with brim, are not a source of mosquitoes. Fish are mosquito predators. However, drainage ponds located in parking lots and other commercial areas can be larval habitats, he said. Gambusia, or mosquito fish, can grow in these smaller ponds and control mosquito populations.

Serious Health Risk

Mosquitoes can leave behind more than itchy bumps when they bite. They transmit several serious diseases, including Eastern equine encephalitis, LaCrosse encephalitis and West Nile virus. All of these diseases can produce encephalitis, which is inflammation of the brain, and are extremely serious when a full-blown case occurs.

According to the Georgia Division of Public Health, five people reported West Nile virus from mosquito bites in 2008, and 47 cases were reported in 2007. Five people reported LaCrosse in 2008. Twenty horses were diagnosed with Eastern equine encephalitis last year. Once an animal is infected, they often die in 48 to 72 hours. Horses can be vaccinated against the disease.

“First and foremost, homeowners need to be concerned about Eastern equine encephalitis,” Gray said. “This disease is a real threat, and children and horses are the most susceptible.”

If not fatal, the disease can cause life-long disabilities, he said, and conditions now are perfect for its spread.

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

April R. Sorrow is a science writer with the University of Georgia Public Affairs Office.