Staff Photo: Karen Rohr. After being out of town for several days, Rockdale County Extension Director Jule-Lynn Macie pours out rainwater, teeming with mosquito larvae, which collected in a container on the back porch.
With summer bringing hot days and afternoon showers, mosquitoes are out in full force. It's difficult to spend any length of time outside without having to deal with the risk of getting bitten.
Where do all these bloodthirsty insects originate? Most likely, in your backyard in amounts of water so minute you might not even know it exists.
Mosquitoes can propagate only if the females have water in which to lay their eggs. It could be water in a bucket, a birdbath, an old tire, a toy, a dog dish, a rain barrel, clogged gutters, a plant dish or even a container as small as a soft drink lid or potato chip bag.
Experts say the No. 1 way to combat the mosquito is to remove all standing water from the yard. Since it only takes about seven days for mosquitoes to transform from larvae living in the water to adults flying in the air, water must be dumped out at least on a weekly basis.
"The main thing is to keep them from breeding, because they will lay loads and loads of eggs," said Joseph Sternberg, director of environmental health for the East Metro Health District.
Once the larvae plunges to the ground, with no water in which to grow, they die. Water that can't be removed, like detention ponds, can be treated with over-the-counter larvicide, deadly to mosquito larvae but not to fish or birds.
"Be an inspector in your yard," recommends Jule-Lynn Macie, director of the Rockdale County Extension Office.
Even if every precaution is taken to empty water from the yard, that might still not be effective, Macie said. Mosquitoes can travel a mile to find a host.
"You can still get them from your neighbors, and you can't do anything about that," Macie said.
The next line of combat is to protect the body with repellent, ideally one that contains some amount of DEET, a synthetic chemical which actually doesn't kill the mosquitoes, but does drive them away. There's a range of products on the market that can serve every situation from the hiker in the deep woods to the 2-year-old playing in the sandbox.
In addition to DEET, the Center for Disease Control also recommends two other repellents: picaridin, and oil of lemon eucalyptus, which should not be used for children under age 3.
Other herbal products are on the market, but Macie said they may or may not work and some haven't been EPA tested and approved.
"A lot of those home remedies are just that, home remedies. I'm not willing to go with a home remedy when there's West Nile, encephalitis and malaria," Macie said.
Wearing long sleeves and long pants, as hot as it may be, is also effective in keeping bites to a minimum.
Experts also recommend staying indoors at dawn and dusk when mosquitoes are most active.
What about foggers or mosquito traps that claim to reduce the mosquito population in the yard?
Foggers only kill adult mosquitoes that are directly hit with the pesticide, and last a limited time. Macie said if you're having an outdoor event, spray before the gathering and you might get some relief, but the insects will be back in a few hours.
Mosquito traps which emit carbon dioxide can kill mosquitoes, but it will also attract them. The gas is also affected by wind direction.
How about citronella plants or candles? Macie said you'd have to plant your whole yard with citronella in order for it to be effective. As far as candles are concerned, they work best when several are used in a semi-enclosed area with no air movement.
When a human (or animal) gets bitten by a mosquito, it's always a female mosquito that does the damage. That's because the females must have blood to produce eggs. When she bites, she's not drinking blood for nourishment; she's consuming for reproduction. She eats flower nectar, juices and decaying matter.
The reaction most humans have to the bite, a little red bump, occurs not because she has injected poison into the site, but rather because the human immune system is having an allergic reaction to the mosquito's saliva.
Beyond the irritation of the bites, mosquitoes can carry diseases including West Nile virus, encephalitis and malaria. According to the CDC, West Nile virus has been reported in Georgia mosquitoes this season, though no human cases of the virus have yet been identified in 2011.
While some counties test mosquitoes on a regular basis for the virus, the insects are not tested in Rockdale or Newton counties because it is presumed that the mosquitoes do have the virus, said Sternberg.
"It's considered endemic here," he said.