The University of Georgia College of Agricultural & Environmental Sciences
Cooperative Extension Service
Controlling Mosquitoes Around Our Homes and Neighborhoods
Revised and updated by Elmer Gray and Ray Noblet
University of Georgia Cooperative Extension Service and Department of Entomology
Mosquitoes can be a vexing and sometimes serious problem. In homes, yards, and public parks, they can interfere with chores and spoil enjoyment of leisure time. Certain species of mosquitoes are also able to transmit diseases such as malaria to humans, various types of encephalitis to human and horses, including the recently introduced West Nile virus, and heartworm to dogs.Breeding Habits
|Figure 1. A typical mosquito life cycle.|
In most parts of the United States, mosquitoes breed during the spring, summer, and fall. In warm, southern locations, they may breed throughout the year during wet periods. Water is necessary for mosquito development (Fig. 1). Female mosquitoes lay their eggs on the surface of a body of water or in places that later become flooded. Different species require different types of water habitats. There are over 60 species of mosquitoes in Georgia. Fortunately, only 10 or 12 are pests to man.
Examples of larval mosquito habitats include salt marshes, swamps, woodland pools, artificial containers such as tires, polluted water in ponds and ditches, and tree holes. After the eggs hatch, larvae develop through 4 instars. Under ideal conditions of warm temperatures and abundant food, the larval stage may only require 4-5 days. After completing the larval stage, pupation occurs. The pupal stage is short in duration, typically requiring 1-2 days before the adult mosquito emerges onto the water’s surface.
Biting and Flight Habits
Both male and female mosquitoes feed on plant nectar to provide energy for flight. However, only females seek blood meals to acquire nutrients needed to produce eggs. During blood feeding, females inject saliva to keep the blood from coagulating and aid ingestion. It is this saliva that causes the irritation and welt that is associated with mosquito bites. Most female mosquitoes seek a blood meal at dawn and dusk, but there are exceptions. The yellow fever mosquito, Aedes aegypti, and the Asian tiger mosquito, Aedes albopictus, will bite during the day, more commonly in shaded areas. Both of these species breed in artificial containers, being especially attracted to tires. The Asian tiger mosquito will also breed in tree-holes that hold water. This mosquito came to the U. S. from Asia, was first found in Georgia in 1984, and is now in every county in the state. This species has become a more serious nuisance than the original yellow fever mosquito that bred in similar locations and has similar habits.
Most mosquitoes can easily fly 0.5-1.5 miles from their breeding area to seek a blood meal. However, there is a considerable amount of variation in this area of mosquito biology. Salt marsh mosquitoes may fly 25-35 miles from their breeding site, while aegypti and albopictus fly only a few hundred feet. The Culex species, which are thought to be the primary vector of the WNV (especially Culex quinquefasciatus in Ga.), typically fly 0.5-1.5 miles from their breeding sites.
Mosquitoes can function as vectors for a variety of disease organisms. Vectors pick up a disease from one host and carry it to another. The introduction of the West Nile virus into Georgia has reminded us how important and effectively mosquitoes can function as vectors. There are several viruses transmitted by mosquitoes in Georgia that can cause encephalitis (inflammation of the brain). The elderly, individuals with compromised immune systems and children are usually the most susceptible. The four most common types of encephalitis in Georgia are the newly introduced West Nile virus, LaCrosse encephalitis, Eastern equine encephalitis and St. Louis encephalitis. Fortunately, transmission of viruses that cause encephalitis is rare in Georgia. Like encephalitis, yellow fever, dengue, and malaria were once common diseases in Georgia. However, they have long been eradicated. The mosquitoes that carried these diseases are still present, but in the absence of the disease agent, the primary discomfort now is the bite itself.
Mosquitoes (or any other insect) do not carry the AIDS virus.
Because some mosquitoes can fly long distances, many communities in Georgia have organized mosquito control programs to provide area wide control. Support of your local program, if you have one, is your best option in preventing mosquito borne illness. The recent spread of WNV has renewed interest in organized mosquito control throughout the state. Integrated control programs operated at the community level will provide the most effective and efficient levels of mosquito suppression.
However, many mosquitoes that bite you may be breeding in your own yard. If mosquitoes are biting you during the day, you probably have Aedes albopictus (Asian tiger mosquito). Since they don’t fly very far from their breeding area, you could be raising them in your own yard. Below are methods you and your neighbors can use to reduce mosquito breeding:
Clean out eaves and gutters.
Remove old tires or drill holes in those used for playground equipment to allow them to drain. Tires are very attractive breeding sites for several mosquitoes that bite humans. Cover stacked tires with plastic or store under a shelter to avoid rain filling them with water.
Check boats for holding water, clear drain hole, turn over, cover or increase angle to aid drainage.
Check tarps on boats or other equipment/items that may collect water in pockets or indentations.
Remove vegetation or obstructions in drainage ditches that prevent the flow of water.
Turn over or remove plastic pots.
Pick up broken, unused or discarded toys that hold water.
Pick up all beverage containers and cups.
Replace water in birdbaths twice a week.
Replace water in pet and other animal feeding dishes or troughs at least twice a week.
Fill tree holes (hardwood trees) that hold water with sand.
Dispose of broken or unused kiddie pools.
Pick up plastic wrappers used for food or other products; mosquitoes can breed even in a discarded potato chip bag that has collected water.
Don’t leave garbage can lids lying around upside down.
Change water in bottom of plant containers, including hanging plants, at least twice a week.
Fix dripping outdoor faucets that create pools of water.
You can avoid or repel mosquitoes by the following:
Keep window screens and screened rooms in good repair.
Screen doors should open outward and have automatic closing devices and latches to prevent them from being accidentally left ajar.
Wear protective clothing, long pants, long-sleeve shirts, shoes and socks during times and in locations of high mosquito incidence. Mosquitoes are less attracted to light clothing than dark. Be aware, mosquitoes can bite through T-shirts and other lightweight, tight-fitting clothing.
During periods of excessively high mosquito incidence, stay indoors as much as possible.
Use insect repellent before going into high-risk areas or when outside during high-risk periods (dawn and dusk) when mosquitoes are present. The most effective protection can be obtained through the use of products containing N, N-diethyl-m-toluamide (Deet). This product is sold under a wide variety of trade names. Follow the directions carefully and do not over apply. Mosquitoes will bite unprotected skin, so apply repellent to all exposed areas of the body as well as to your clothing (using deet in an aerosol). Don’t allow repellent to get in your eyes, mouth, or nose. The American Academy of Pediatrics recommends that repellents appropriate for use on children from birth to five years of age should contain no more than 10% Deet. In addition, it is recommended that children NOT be allowed to apply repellents to themselves. Repellents should be applied to an adult’s hands and then applied to the child. The repellent should not be applied to the child’s face or hands and the treated areas should be washed after the threat of mosquito bites diminishes. Permethrin is another repellent that should be used on clothing only. Trade names include Permanone and Duranon. Permethrin, not only repels but also kills, and is longer lasting than deet. For maximum protection use Deet on the skin and permethrin on clothing.
Do not rely on electronic bug killers or ultrasonic (sound) repellents for protection. They have not been scientifically proven to be effective.
Mosquitoes don’t like strong wind currents. Sitting by a fan will repel them.
Call the environmental health unit of your county health department to find out if there is a mosquito abatement program (spraying) in your area. If not, extra care in following these recommendations may be warranted.
There are a variety of methods to kill mosquitoes:
- Pyrethrin aerosols will kill mosquitoes in the house.
- Hand held fogging devices using a pyrethroid insecticide can be purchased from hardware and garden shops to give temporary control outdoors. These units cost approximately $60.00 each and usually use resmethrin as the insecticide. Be sure to buy the insecticide that goes with the device. These foggers are available at Lowes, Home Depot, Ace Hardware and others.
- Residual insecticides (malathion, permethrin) can be applied to areas where mosquitoes rest during the heat of the day. Sites may include shrubbery, ground covers and underbrush.
- Burning mosquito coils, usually containing pyrethrin, at a stationary location outside can give relief in the immediate area.
- Goldfish in ornamental ponds will feed on mosquito larva.
- One tablespoon of salt or two squirts of dishwasher detergent in an automobile tire will kill the mosquito larvae.
If your community has an organized mosquito program, it can be effective in greatly reducing mosquitoes that bite in the evening. These are usually controlled by applying ultra low volume-ULV (aerosols) sprays in the evening that drift through the area killing flying evening mosquitoes. The day biting Asian tiger mosquito and yellow fever mosquito are resting in the foliage and other protected areas in the evening and are not as susceptible to the spray as mosquitoes that are active during this period. If the ULV application is conducted during the day for these mosquitoes, rising air currents from the heat of the sun will cause the spray to go upward and be ineffective, rather than drift low to the ground as it does in the evening.
Since conventional adult spraying is not going to be completely effective in controlling the day biters, controlling the larva in the breeding container is the best option. Unfortunately, government mosquito programs are not likely to enter private property to treat containers. This means you will need to control these mosquitoes yourself.
Remember, the day biters don’t typically fly far (100-300 yards) from their breeding containers. If you or your neighbors remove, cover or empty breeding sites, you can greatly reduce your problem. You should not have expectations that a city or county mosquito program will be able to control these day biters for you.
With the introduction of the WNV into Georgia and the unprecedented level of disease activity, the public has recognized a renewed threat from mosquitoes. In the recent past, the greatest importance mosquitoes had in Georgia was the discomfort from their biting. Unfortunately, this is not the case any more. However, by reducing the breeding sites on your own property and taking a few simple precautions, you can reduce the threat of mosquito borne illness and annoyance in and around your home and neighborhood.
Revised and updated by Elmer Gray and Ray Noblet, University of Georgia, Cooperative Extension Service and Department of Entomology. September 17, 2002.
The University of Georgia and Ft. Valley State College, the U.S. Department of Agriculture and counties of the state cooperating. The Cooperative Extension Service, University of Georgia College of Agricultural and Environmental Sciences offers educational programs, assistance and materials to all people without regard to race, color, national origin, age, sex or disability. An equal opportunity/affirmative action organization committed to a diverse work force.
Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.
Gale A. Buchanan, Dean and Director