Health & Medicine

Mosquitoes invading Kentucky in a big way this year because of rainy weather

Mosquito Squad employee Cole Craven sprayed for mosquitoes at a home in Lexington last week.
Mosquito Squad employee Cole Craven sprayed for mosquitoes at a home in Lexington last week. Lexington Herald-Leader

If you've done any yard work in the early morning or late afternoon recently, you've probably noticed a familiar, nerve-jangling humming around your ears.

Let the swatting and slapping begin.

Mosquitoes are back, and in a big way.

All the rain earlier this summer created countless places in Kentucky for mosquitoes to breed. And the current hot, humid weather is perfect for helping mosquito eggs turn into biting adults in as little as five days.

In other words, the tiny blood-sucking pests are all set to drive us crazy for the next few months.

"They are hitting their stride right now for sure," University of Kentucky extension entomologist Lee Townsend said. "We're going to be in mosquito mode until around the time of the first frost."

The Lexington-Fayette County Health Department, which oversees public mosquito-spraying operations, already has seen an uptick in complaints about the critters.

In May and June 2012, the department received 30 complaints. During the same period this year, there were 50.

Luke Mathis, an environmental health supervisor with the health department, attributes the increase to this summer's wet weather, noting that last June and July were drier.

"We're getting a lot of complaints that mosquitoes are particularly aggressive this year," Mathis said.

About 50 mosquito species live in Kentucky.

But experts say that the big trouble-maker in the Lexington area is one named the Asian Tiger, which likes to operate outdoors in daylight, and the so called "house mosquito," which works the night shift and invades homes through open windows or doors.

Chris Christensen, an entomologist who operates Urban Insect Solutions and Critter Control in Lexington, calls the Asian Tigers "vicious biters"

"These things come up out of the grass, they haul off and they bite and welt," Christensen said. "And everybody's breeding them in their backyards."

Asian Tiger mosquitoes can breed in still water that's as shallow as a quarter of an inch, experts say. And there are few Lexington homes that don't have a clogged gutter, an outside pet dish, a swing set or some other place where rainwater can collect and provide a prime mosquito breeding area. The city's shrubs, trees and bushes offer perfect places for the pests to hide and rest between attacks on unsuspecting humans.

A mosquito in biting trim weighs in at about 2.5 milligrams, and some are so small they're hard to even see.

But some experts argue that the mosquito might be the deadliest animal on earth, blamed for 1 million deaths worldwide each year. Mosquitoes cause all this suffering through the infections they spread with their bites. The most serious is malaria, which kills an estimated 600,000 people annually. Many of the victims are children.

Fortunately, we don't have to worry about mosquitoes spreading malaria here. The disease was eradicated in the U.S. by the 1950s.

In recent years, however, mosquitoes have been blamed for carrying West Nile virus, a potentially fatal infection that first appeared in New York in 1999. The illness now has spread to every state except Hawaii and Alaska.

Dr. Craig Humbaugh, the Kentucky state epidemiologist, said West Nile cases spiked in Kentucky last year, as they did in many Southern states, with 20 confirmed cases here. No cases have been confirmed this year, he said.

Kentucky recorded three West Nile fatalities last year.

Humbaugh noted that mosquitoes can carry other serious infections, such as viruses that cause some types of encephalitis.

All that means it's wise to avoid mosquito bites at all times, Humbaugh said.

One way to do that is by checking around your house regularly and eliminating places where rainwater can collect. If you doubt the importance of that, note that the Asian Tiger mosquito apparently arrived in the United States in the early 1980s in a shipment of old tires in which rainwater had collected. The Tigers spread to Kentucky about 1990.

"The Asian Tiger generally stays within about 100 yards of where it is bred," Townsend said. "So you can do a lot to manage the problem just by making sure you don't have standing water around your house."

The house mosquito can be a trickier problem. It can travel a mile to bite its victims, Townsend said.

Citywide spraying by the health department helps. Mathis, the department's health supervisor, said department crews spray overnight and during early morning hours in trouble spots, usually areas where there are natural water-holding areas such as creeks, lakes or ponds.

Mathis said the department uses Duet, a chemical that targets mosquitoes and other night-flying pests but doesn't harm butterflies, bees and other beneficial insects.

Professional spraying services say they can offer a more targeted approach to solving individual homeowners' mosquito problems. But no property is going to be completely mosquito-free, they say.

"When we do mosquito control for a customer, you should see a good reduction in bites," Christensen said. "But don't think you won't see any more mosquitoes. Because you will."

Sarah Griggs, who owns the Lexington franchise of Mosquito Squad, says her company's spray can rid an area of most of its mosquitoes for 21 days.

Homeowners can help themselves by tipping over buckets or other containers that hold standing water, removing brush or undergrowth where mosquitoes can hide out, and discarding yard detritus that holds moisture, Griggs said.

"Even a Coke bottle cap that you've got somewhere, thousands of mosquitoes can breed in that," she said.

Mosquitoesand disease

Mosquitoes transmit several diseases, including West Nile virus, encephalitis and malaria. Mosquitoes often prefer to feed on birds, so they can have a high rate of infection. Two common bird species known to carry the encephalitis virus are the house sparrow and house finch.

A low-tech mosquito repellent

If you're outside at, say, a cookout, or just sitting on your porch, simply putting a fan blowing in your direction will help protect you from mosquitoes. Oscillating tends to work best, but a box fan is also effective.

Why? Mosquitoes are relatively weak flyers, according to the non-profit American Mosquito Control Association. They don't like to or are unable to fly through the breeze created by a fan, researchers say. Plus, the fan might help dissipate the bug-attracting chemical signals your body is putting off.

Read more about this technique in Saturday's Life + Home or at

Did you know?

■ There are about 2,700 species of mosquitoes, but not all species bite humans.

■ Females drink blood and the nectar of plants; the males only sip plant nectar.

■ Ultraviolet lights and ultrasonic devices are not effective repellents.

■ Is it a bite or a sting? Well, that depends. A mosquito has no stinger, but part of its mouth is a syringe-like needle that penetrates the skin, so it's usually called a bite.

■ That "giant mosquito" you saw flying around your porch light is likely a crane fly, and it's harmless to humans.

Tracking you down

A mosquito has many ways of finding you: by sight, smell, chemical signals and body heat. Confusing the signals by applying the chemical DEET is one of the best solutions. Look at the wily ways the female mosquito finds you:

■ Chemical sensors: They can sense carbon dioxide and lactic acid up to 100 feet away. Sweat also seems to attract mosquitoes — people who don't sweat much don't get as many bites.

■ Heat sensors: Mosquitoes detect heat, so they can zero in on warm-blooded animals. Staying cool — at least cooler than the person sitting next to you — might help avoid bites.

■ Visual sensors: Dark clothing makes you stand out and attracts mosquitoes. Try wearing light-colored clothes. Movement also attracts mosquitoes.