By Elmer Gray
University of Georgia
Asian tiger mosquitoes were introduced into this country in Houston, Tex., in the mid-1980s. Since then, they've spread through much of the eastern United States. They're not thought to be major disease carriers yet in this country. But they are aggressive daytime biters, so considerable efforts are spent trying to reduce their larval habitats.
These mosquitoes are black and white, with a characteristic median, white stripe on the thorax, lateral stripes on the abdomen and striped legs. These markings and their aggressive daytime biting make them fairly easy to identify.
Mosquito havens
They prefer to breed in any kind of container that will hold water. The container breeding and daytime activities make them hard to control through conventional practices such as large-scale treating with larvicides and adulticides.The best way to prevent nuisance populations is simply to eliminate all forms of standing water around our homes and neighborhoods. Target buckets, pet dishes, tarps, toys, used tires and any debris that will hold water.
And don't just check once. Getting rid of standing water around our homes and neighborhoods should be a way of life, not a one-time or even a once-a-month routine.
Asian tiger mosquitoes aren't strong fliers. They often don't move more than 100 yards from where they hatch. So, if you have a lot of them around your home, you won't have to look far to find their larval habitat.
Swarms of skeeters
That is far different from what many Georgia residents face in the lower portion of the state. There, large lowland areas provide ideal breeding sites for many native mosquito species.South Georgians don't want to think of Asian tiger mosquitoes. They've been dealing with heavy populations of other mosquitoes for more than two months as a result of the heavy rains in early spring and wet conditions stretching back to last year's hurricane season.
Native flood-water mosquitoes have been particularly troublesome where most low-lying areas have been inundated with water for long periods over the past eight months.
Fortunately, no significant mosquito-borne disease outbreaks have been reported, although two cases of Eastern Equine Encephalitis have been reported this spring.
Diseases
These have involved a horse from Bacon County and a flock of quail in Lanier County. Both are indicators that there is viral activity in the local mosquito populations. People who live in these areas should be particularly cautious.On the West Nile virus front, news has been quiet so far this season. As of May 16, no WNV-positive birds, horses, mosquitoes or humans have been reported this year.
That's not completely unexpected, since the peak period for WNV in Georgia continues to be August and September. The peak period coincides with hurricane season, and last year's active season may have suppressed West Nile activity.
In Georgia, the primary carrier of West Nile virus is the Southern house mosquito (Culex quinquefasciatus). This mosquito breeds regularly in storm drains and sewer systems, which are flushed of stagnant water by periods of heavy rain.
In 2004, Georgia had 22 verified cases in humans, with one death. Three horses and 105 birds tested positive for the virus. Nationwide, 2470 human cases and 88 deaths were reported in 41 states.
(Elmer Gray is an Extension Service entomologist for the University of Georgia College of Agricultural and Environmental Sciences.)
