larvae southern house mosquitoLarvae of Southern House MosquitoThe West Nile Virus was introduced into the United States in 1999 and quickly spread throughout the nation. The virus lives in bird populations and is spread when a mosquito bites an infected bird and then a human. Of persons who become infected, only about twenty percent will develop any symptoms but around one in 150 will develop the severe form of the disease, an encephalitis which can kill or cause life-long disabilities. Common symptoms include some or all of the following: fever, headache, tiredness, and body aches occasionally with a skin rash (on the trunk of the body) and swollen lymph glands. While the illness can be as short as a few days, even healthy people have reported being sick for several weeks. The severe form of encephalitis may involve headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis. Of those that develop encephalitis, 3 to 15% will die.

Everyone has heard of the severe outbreak of West Nile Virus in Dallas, Texas and it appears that Georgia will have more cases this year than average. The mosquito that is primarily responsible for spreading the West Nile Virus from birds to humans in Georgia is the Southern House Mosquito, Culex quinquefasciatus. Southern house mosquitoes are generally foul water breeders. They breed in catch basins, storm water outfalls and residential containers of all kinds.

Past investigations have found Culex quinquefasciatus breeding the following locations: open septic tanks, buckets, boats, ornamental ponds, tires, rubbish bins, dumpsters, plastic containers, vases flower pots, fountains, swimming pools, hot tubs and wheel barrows - almost anything that will hold water for a week or more.

The type of mosquitoes and their impact on your daily activities will vary, depending on where you live. In heavily urbanized areas residents will more likely be affected by pesky container-breeders while rural residents may be affected by mosquitoes that breed in natural environments such as tree holes, puddles, and other stagnant shallow water. Mosquitoes never breed in running water and are usually kept in check by the small fish in ponds and lakes.

But no matter where we live, there are some general guidelines we can all follow to minimize the incidence of mosquitoes and our exposure to the diseases they transmit:
  • Remove all standing water from your yard by emptying and cleaning all containers, even very small ones. For example, do not leave toys that can retain water outside; remove saucers from under flower pots; clean or remove pool covers; clean pools and keep water chlorinated; cover rain barrels with mosquito proof netting; clean clogged rain gutters and rain spouts.
  • Controlling adult mosquitoes is a thousand times more difficult and costly than controlling mosquito larvae. If you have to control adult mosquitoes in your yard, remember that mosquitoes have a long history of developing resistance to insecticides when applied incorrectly. Only a limited number of insecticides prove effective in adult mosquito control, therefore it is important that applications be made correctly according to the labeled instructions specifically for adult mosquito control. In general, trying to control adult mosquitoes yourself is going to be difficult. Some fogger products such as Raid Yard Guard may provide temporary relief and some pest control companies sell automatic misters, carbon dioxide attraction traps and similar products. If you use a carbon dioxide unit, place it AWAY from you house, not on the deck or near a door or you will bring mosquitoes into your house. Citronella candles, mosquito coils, campfires and incense will only work effectively in the range of their smoke reach. Therefore they can rid an area of mosquitoes to a certain degree, but they won't prevent bites from the most stubborn of blood-suckers who will still find their way to you around the smoke. Citronella candles and mosquito coils are also ineffective mosquito deterrents in strong winds. Ultrasonic mosquito repellant units are a joke.
  • If you have standing water in your yard, you may apply insecticides yourself to control mosquitoes in the larval stage. Use products containing Bacillus thuringiensis israeliensis (Bti) or methoprene (Altosid) and always follow the directions on the label. The best possible larvae control with least environmental and human health impact is found with Bacillus thuringiensis israeliensis (Bti), which you can buy at any hardware store. They come in little donuts 6 or 8 to a package and are inexpensive. A small amount of stagnant water only needs a small piece of a donut. Bacillus thuringiensis is a bacteria that kills mosquito larvae by infecting their guts.
  • If the source of mosquitoes (stagnant water) is on another property, contact your county environmental health office for assistance. Some counties have mosquito control programs and regulations but most do not. Your environmental health officer may be able to help resolve issues of mosquito breeding on other nearby properties but it depends on local regulations. Abandoned swimming pools can breed hundreds of thousands of mosquitoes.
  • Organize or participate in clean-up activities to pick up garbage from parks and other public spaces. Some very common items that breed mosquitoes are old tires, garbage cans, trash dumps, bird baths, tree holes, stopped-up gutters, puddles, right-of-way ditches that hold water, small decorative fish ponds with no water circulation, and just about anything that holds stagnant water for two weeks or more. By helping limit potential breeding grounds for mosquitoes, every resident can contribute to reducing the nuisance caused by mosquitoes and stop the transmission of mosquito-borne diseases.
  • Limit your time outdoors during dusk, dawn and at night. When outdoors, wear clothing that covers your arms and legs. Most mosquitoes will bite through simple cotton T-shirts. Always use mosquito repellants if you must be outdoors. Small children, the elderly and those with compromised immune systems are the most frequent victims of West Nile. Seek medical attention at once if you have symptoms suggestive of West Nile.


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