August 2002 The Asian Tiger Mosquito and Personal Responsibility Aedes albopictus, better known as the Asian Tiger mosquito, is a recent import, coming to this country in a shipment of used tires from northern Asia, its native land. First discovered in Houston, Texas in 1985, it has spread to all states east of the Mississippi River and north into Canada. It first showed up in Florida in a tire collection dump in Jacksonville in 1986 and has now spread to all of Florida. Not only is it a major nuisance, but it has also been shown to be an effective vector of 23 arboviruses in the laboratory. In nature, it has bee associated with Easter Equine Encephalitis (a single incident in Polk County in 1991), is suspected in the transmission of West Nile Virus in the United States, and is the primary vector involved in the transmission of Dengue virus in Southeast Asia, southern China, and Japan.
Aedes albopictus is easily recognized. It is a small black mosquito with a thin white stripe running down its head and back. This mosquito is a daytime biter so there should be plenty of light available to get a good look. The next time a mosquito lands on you take a quick look before slapping. If there is a thin white line on the mosquito’s back, it is Aedes albopictus. It is very important to identify this mosquito, because if it is Aedes albopictus then it is breeding in some sort of water holding container close by, within a couple hundred feet. This mosquito lays its eggs in items that hold relatively small amounts of water. Examples are tires, pans on the bottom of potted plants, buckets, animal watering troughs, rain gutters that are clogged or have a low area in them, boats left in the weather, cans, paper cups, Styrofoam containers, plastic toys, tarps used to cover equipment, plants called bromeliads that hold water in their leaf axials, large Magnolia leaves that hold water. I’ve even seen them use a 55-gallon drum that had a lid on it, they were breeding in the 1/4 inch of water being held in the lid.
Aedes albopictus is a floodwater mosquito, meaning that it lays its eggs above the waterline, not on the water. These eggs can stay dormant and viable, out of water, for years. When the container that the eggs were laid in fills with water, the eggs hatch. In a week or so they emerge as adults, mate and then wait for a bloodmeal. This mosquito has evolved with man, using containers he provides and then feeding on him and his animals for the protein needed for egg production. We have, in essence, domesticated this mosquito. Being domesticated, it doesn’t need to actively seek a bloodmeal or a place to lay their eggs, we provide these essentials for them. So the behavior of this mosquito is to just wait, in a protected area, near the containers she hatched from, for a host to show up. When the female mosquito senses a person or animal she takes flight, feeds, goes back to her protected (from wind, rain and sunlight) area, develops her eggs, then lays them in a container, usually the one she grew up in, and starts the next generation. Aedes albopictus is a day feeder, feeding anytime during the day in the shade, but is worse in the early morning or late afternoon when wind speed and light intensity decreases. This mosquito is quite the nuisance. Its bite is so itchy that in some people the reaction is like a stinging sensation.
So what’s the solution to getting rid of this mosquito? Because it feeds in the daytime and flies only when a potential bloodmeal is sensed, spraying with an aerosolized pesticide si very inefficient, if not useless. Why? Because if the insect you are targeting is not actively flying it won’t come in contact with the pesticide. Additionally, releasing an aerosol during daylight hours usually has no effect because the thermals and swirling winds created by the heating from the sun, simply blows the pesticide away, out of the target area. Even if we could get a good kill by spraying pesticides for this mosquito, which we can’t, albopictus continues to emerge from the containers and the biting adults will be back in full force within a day or two. The solution to controlling and even eliminating this mosquito is to empty and REMOVE (from exposure to rain) the containers they use to deposit their eggs in. By eliminating all water holding items the adult female will fly out of the area to find a suitable place to deposit her eggs. This mosquito will not hang around for a bloodmeal it is has no water holding containers for her eggs. This mosquito can be eliminated, without pesticides, by simply recognizing what they need to breed in and removing it. That means an effort from homeowners to empty and eliminate water-holding items around their homes.
So what does South Walton Mosquito Control do to control Aedes albopictus? In south Walton if we get a complaint and suspect this mosquito we will inspect the area, find the sources, show the container with the larva to the homeowner and educate them about this mosquito. We treat over 2,500 catch basins throughout the District with an insect growth regulator. Catch basins act as containers, they can’t be eliminated, so we treat them. Catch basins are an integral part of designed drainage systems, but they need to be re-engineered so that they don’t hold water. But for now we treat them. We provide educational presentations to homeowner or civic organizations to make folks aware of this mosquito and the problems it can cause. We provide brochures, free of charge, at our Mosquito Control Office, the Chamber of Commerce, and the Tourist Development Council. We provide dumpsters for the disposal of tires and old appliances located at our facility, free of charge. Additionally, we place articles in newspapers, such as this one, to get the information out to the public on how to deal with this mosquito.
Controlling the Asian Tiger mosquito is our biggest challenge, it requires educating the public. The common demand I hear from individual citizens is “Just spray! I pay taxes! Just spray!” Unfortunately, spraying does not solve the problem. If it did, it would make my job a whole lot easier. When we spray and this mosquito is the cause of the problem the typical response I get is, “Your truck sprayed the other night but the stuff you are spraying didn’t work, the mosquitoes are still bad.”
Ultimately, this mosquito can be controlled, even eliminated, but it takes cooperation, education, and personal responsibility. We, as a mosquito control agency, do not have the resources to go around to every home and business to empty and eliminate water holding, mosquito producing items. This work has got to be done by the homeowner or maintenance crews of apartment, townhome or condominium complexes. Make sure your rain gutters are clean and functioning properly, that the land or road drainage system in your community is operating as it should, cut down trees with treeholes or fill the holes with sand, remove water holding items from the environment, clean pet watering bowls and bird baths once a week, talk to your neighbors about items that could be producing mosquitoes, place tarps tightly over equipment and boats so no water puddles in them, turn over small boats and wheelbarrows so they don’t hold water, remove the water catchers from beneath potted plants that are outdoors, get rid of bromeliads or spray them with a cooking oil once a week, rake up Magnolia leaves, clean up any cans or trash that can hold water, bring you old tires and appliances to our facility for disposal, have your homeowner or civic association call us for an educational presentation, call us to have your property inspected for possible mosquito causing situations and last and most importantly, maintain an awareness and the effort needed to eliminate water holding items. If we don’t change the way we live, we will be bothered by this mosquito for the rest of our lives. |