Preventive measures to reduce your risk for WNV infections include reduction of mosquito breeding sites and prevention of mosquito bites.
 Reducing Mosquito Breeding sites in your yard and neighborhood
Eliminate sources of standing water in your yard where mosquitoes may lay eggs. Fill, cover or remove any items that can trap water. Common mosquito breeding containers include:
- Bird baths - change the water at least once or twice a week, cleaning the bath on a regular basis
- Outdoor pet dishes - change the water daily, not only to prevent mosquito breeding, but also for your pet's health
- Flower pots - remove any overflow water that has collected in the dish beneath the pot
- Ponds - consider purchasing mosquito-eating fish if the pond is serving as a mosquito breeding site and cannot be drained
- Tires
- Gutters - clean and remove debris on a regular basis to prevent water from collecting
- Wheelbarrows
- Wading pools
- Trashcan lids and recycling bins
- Puddles/ditches in your yard or driveway
- Swimming pools (not in use) - keep pool water aerated and chlorinated; cover when not in use
Trim grass regularly Preventing Mosquito Bites
ALWAYS FOLLOW MANUFACTURER'S INSTRUCTIONS ON REPELLENT USE!
- Use a mosquito repellant, such as one containing DEET when outdoors. Look for "DEET" or "N,N-diethyl-m-toluamide" or
"N,N-diethly-3-methylbenamide" on the product label.
- Wear light-colored, long-sleeved shirts and pants, as well as covered shoes with socks, in mosquito-infested areas; you may wish to wear mosquito netting over your face as well.
- Limit outdoor activities at dawn, dusk, and early evening, when mosquitoes are most active
 More About DEET
According to a recent study, products containing about 24% DEET were effective for an average of 5 hours against mosquitoes; a product with 20% DEET was effective for about 4 hours; and a product with about 6.5% DEET was effective for about 2 hours. Weigh the strength of DEET you use against the number of hours you will be exposed outdoors. Remember that you can and should re-apply DEET if you extend your time outdoors.
- Concentrations up to 35% DEET may be used by adults; higher concentrations are not more
effective at preventing bites. The percentage of DEET in a product has more to do with its "staying power" than
its effectiveness at warding off mosquitoes. A product with 50% DEET is not really more effective at preventing
mosquito bites, but simply lasts longer on the skin that a product containing 20% DEET.
- Use formulas with a maximum concentration of 10% DEET on children, and don't allow them to apply the
product themselves; avoid using DEET on infants and toddlers
- Don't apply DEET products to your face, as it should be kept away from eyes and mouth.
- Don't apply DEET products to sunburned, cracked, bruised, or irritated skin
- Apply DEET in ventilated areas
- Use DEET products sparingly, and apply only to exposed skin and to clothing
- DEET may damage synthetic fabrics
- Although DEET has been tested extensively on humans and has been deemed safe when used properly, you should
avoid prolonged exposure to it; wash skin and clothing after returning indoors
- If you suspect that you are having an adverse reaction to a product containing DEET, wash it off immediately and
contact a doctor or poison control center
- Don't use DEET on your pets; if they ingest it by licking or cleaning themselves, they could become seriously ill.
Resources on Mosquito Control
PUBLICATIONS
Journal of Vector Ecology
Evaluation of Various Models of
Propane-Powered Mosquito Traps (2002)
Large cage and field studies were conducted to determine the efficacy of various models of propanepowered
mosquito traps. (pdf)
FEDERAL AGENCIES
Environmental Protection Agency
Malathion for mosquito control (2000)
A fact sheet about the mosquito life cycle and the use of the pestcide, malathion, in mosquito control programs.
Mosquitoes: How to Control Them (1998)
A quick reference discribes the diseases mosquito carry and outlines actions citizen can take to fight mosquitoes.
ORGANIZATIONS
American Mosquito Control Association
In addition to general information about mosquitoes, this web site provides an extensive list of West Nile Virus related links. The organization mission is to enhance the health and quality of life through the suppression of mosquitoes, other vectors and pests of public importance.
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Mosquitoes 101
Why do mosquitoes bite?
Only female mosquitoes bite. Female mosquitoes require a blood meal to acquire the protein needed to produce eggs.
Females lay multiple batches of eggs during their lifespan, and a new blood meal is needed to produce each batch.
Different mosquito species prefer different host species; some mosquitoes will seek blood meals from birds, others
from mammals - and some are generalists. The female inserts her needle-like proboscis - a slender, tubular, feeding
and sucking organ - under the victim's skin, drawing blood
into her abdomen. She will feed until her abdomen is full, unless discovered and brushed away.
Why do mosquitoes seem to bite some people, but not others?
This phenomenon is not completely understood. Mosquitoes are attracted by the carbon dioxide that we -
and other animals - exhale. They may also be attracted by various odors - perfume, perspiration, lactic acid,
detergents - that combine in unique ways to make one victim more attractive than another as a meal. Because dark
colors absorb heat and lighter colors tend to reflect heat, mosquitoes also tend to be more attracted to victims dressed
in darker clothes.
Why do mosquitoes bites itch and swell?
The itching, swelling, and burning from a mosquito bite are actually caused by the body's autoimmune response to the
saliva injected by the mosquito when she feeds. This saliva contains anti-coagulating agents that prevent the
victim's blood from clotting as it is sucked into the mosquito's abdomen. A bite may take several days to heal and
stop itching; treat it with Calamine lotion or a topical anti-itch medication.
Where do mosquitoes breed?
Mosquitoes breed in wet, swampy areas, where they lay their eggs. The eggs hatch in the water, and the young mosquitoes
spend their pupal stages in the water. Mosquitoes lay eggs in both fresh and polluted water, and seek still waters
such as those found in small puddles, ditches, and ponds. Even a small amount of standing water - say, in the bottom
of a flower pot - will provide sufficient habitat for mosquito eggs. These eggs usually hatch about 5 days after they
are laid. A key factor in mosquito prevention is the elimination of standing water in your area.
What is the average lifespan of a mosquito?
Like most insects, mosquitoes are a prime food source for birds,
amphibians, and spiders. Between predators and extreme weather events such as drought and harsh rains, most mosquitoes
live for an average of about two weeks in their adult form. If they manageto escape predators, females from some
mosquito species live to about two to three months of age. Those females who enter adult form late in the season
may go into hibernation as cooler weather approaches, and can emerge the following spring to lay eggs.
In many species, eggs laid before the onset of cold weather can also survive through a winter, even without water,
re-hydrating in spring rains to go through larval, pupal, and adult stages.
Will winter bring an end to West Nile-carrying mosquitoes?
Yes and no. Like snakes and amphibians, insects are cold-blooded, and cannot regulate their own body temperatures.
Because they are dependent upon their environment to maintain a sufficient body temperature, mosquitoes "disappear" in regions subject to cold winters. Female mosquitoes that survive into the onset of winter can go into
hibernation; if they mated in the fall, they can emerge ready find the first available blood meal, and then lay their
eggs, in the spring. Some mosquito species can lay eggs which survive extreme weather, such as cold, ice, and drought. Moisture produced by spring rains and
melting snow and ice will cause these eggs to hatch, and the mosquitoes will progress through larval, pupal, and finally
adult stages to begin the cycle anew. In the warm and humid climates of the Southeast and Gulf Coast, mosquitoes can
thrive year-round.
How many types of mosquitoes are there?
According to the American Mosquito Control Association, there
are more than 2500 species of mosquitoes world-wide; about 200 of these species occur in the U.S. According to the
National Pesticide Information Center, 36 species occurring in the U.S. have tested positive as carriers of West Nile Virus.
The most common carrier of West Nile is the Culex pipiens (Northern house) mosquito. Other carriers include
Culex restuans , Aedes albopictus, Culex quinquefasciatus (Southern house mosquito), and
Aedes vexans.
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