Mosquitoes Not Just a Nuisance

From a D.C. Department of Health Web site on West Nile Virus (http://dchealth.dc.gov/information/fact_sheets/moscontrol.shtm)

Mosquitoes are not only a nuisance, but may also carry many diseases, including St. Louis encephalitis, eastern equine encephalitis, West Nile Virus and dog heartworm. Several important species breed around the home.

Most mosquitoes that breed around the home require stagnant water rich in decomposing organic material. The female mosquito deposits 100 to 200 eggs on the water's surface or in areas that will later flood. The eggs hatch into worm-like larvae, which are very active and feed on organic material in the water. Within days the larvae transform into the pupa stage, during which legs, wings and other adult features form. When this stage is completed, the adults emerge from the pupa. The entire life cycle from egg to adult can be completed in less than 10 days. Most adults live about two weeks.

One discarded tire can produce tens of thousands of mosquitoes over a season.

The mosquitoes that breed around the home tend not to fly far, and will remain a nuisance to the neighborhood. These mosquitoes feed on humans or pets for a "blood meal," and many will enter houses to feed.

The northern house mosquitoes (Culex pipiens) are commonly found in urban areas. They lay eggs in any receptacle containing water rich in decomposing organic material. Breeding sites include clogged rain gutters, children's wading pools, bird baths, cans and bottles, flower pots trays and discarded tires. Populations peak at mid-summer. Other mosquitoes lay eggs in rotted out tree holes, where a branch has been lost or where several branches meet. Discarded tires full of leaves and other containers are very attractive egg-laying sites. The females feed in the morning and early evening. Other kinds of mosquitoes also share these habitats and will enter your home to feed.

Breeding can be reduced by eliminating standing water. §