Mosquito Management Can Help Reduce Chances of West Nile Virus

Proper mosquito management can help reduce the chances of people and animals being bitten by mosquitoes and contracting West Nile virus and other diseases. Colorado State University Cooperative Extension has several information resources available to the public about mosquito management.

The best mosquito management is preventative and occurs before biting adults appear, but some measures can be taken later in the season to control their populations. The most typical form of controlling adult mosquitoes is applying insecticide, often called adulticiding or fogging. These insecticides are applied over a large area or on a community basis because mosquitoes are strong flyers.

However, steps can be taken around the home to prevent biting-mosquito populations.

– Eliminating standing water, which is mosquitoes’ habitat, by draining low spots, ditches, gutters and similar areas.

– Empty rainwater receptacles, such as bird baths, old tires, etc., at least once a week or remove them.

– Place mosquito netting and tight screens around patios to create mosquito-free areas.

– Reduce unnecessary lighting around a home – mosquitoes are attracted to lights. Bug zappers are not effective at reducing mosquito populations and may kill beneficial insects that prey upon mosquitoes. Ultrasonic devices, such as those that claim to mimic dragonflies, do not affect mosquito activity.

– Adult mosquitoes rest in shrubbery and other shaded areas during the day. These areas can be treated with approved insecticides. Foggers for flying insects can also be used but will provide only short-term relief. Various aerosol insecticides are available for controlling mosquitoes indoors.

– Mosquito-eating fish, called Gambusia, can be released in bodies of water near mosquito habitat.

– Light-colored clothing is less attractive to adult mosquitoes, and tightly woven fabrics give some protection against bites.

Recommendations for using DEET:

DEET is considered the most effective mosquito repellent. However, there is concern about undesirable side effects on young children and others who might be unusually sensitive to this chemical. Side effects have been associated mostly with heavy use to avoid transmission of Lyme disease by ticks. The Environmental Protection Agency recommends the following precautions for using DEET:

– Apply DEET only to exposed skin and clothing, not to skin that will be covered with clothes.

– Avoid frequent reapplication or skin saturation.

– Do not apply DEET to cuts, wounds or irritated skin.

– Keep DEET away from eyes and mouth.

– Do not apply DEET to hands of young children.

– Use products with DEET concentrations of less than 20 percent on children.

– Do not spray DEET directly over the face.

– Avoid breathing DEET aerosol sprays.

– Wash treated skin and clothing after returning indoors.

Facts about mosquitoes:

– There are about 3,500 different kinds of mosquitoes. About 40 of these are found in Colorado. Not all types of mosquitoes feed on humans or transmit disease. Only a few of these kinds of mosquitoes are considered important transmitters of human disease.

– The lifecycle of a mosquito follows four distinct stages: egg, larva, pupa and adult. Eggs are laid in or near water and hatch into larvae. Larvae feed on organic material and small aquatic organisms. Pupae, which also are found around water, is the stage in which mosquitoes begin to transform into adults. Adults emerge from pupae to feed on nectar and pollen and blood from various hosts.

– During the summer, adult mosquitoes have a life span of a few weeks. However, some kinds of mosquitoes spend the winter as adults. Overwintering mosquitoes can live several months.

– Adult mosquitoes can fly a mile or two to feed. Some mosquitoes have been observed to fly 10 miles or more.

– The buzzing sound of a mosquito is actually the unique wing beating frequency of females. This sound is attractive to male mosquitoes of the same species.

– Mosquitoes use a variety of cues to find their hosts, including chemicals such as carbon dioxide and lactic acid, as well as shape, color, heat and humidity. That’s why some people are bitten more often than others; individuals vary in the amount of these "cues" they produce.

Fore more information about mosquito management, visit or contact the local Colorado State University Cooperative Extension office, usually listed under the county government section of the local phone book.