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. This information describes the life cycle and habits of the most common pest mosquitoes, and suggests several ways to eliminate breeding sites. Also, it explains the safe use of insect repellents, and lists additional mosquito web sites for more information.

Mosquito Life Cycle

Most mosquitoes that breed around the home require stagnant water rich in decomposing organic material. The female mosquito deposits 100-200 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.

Mosquitoes that Breed Around the Home

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 mosquito (Culex pipiens), is 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 as 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.

Eliminating Breeding Sites Around the Home

1. Dispose of cans, bottles, and plastic containers. Store items to be recycled in covered trashcans or sealed bags.
2. Eliminate discarded tires. Drill drainage holes in tires used for playground equipment.
3. Clean roof gutters and down-spout screens regularly. Eliminate standing water on flat roofs.
4. Turn over plastic wading pools, wheelbarrows, and canoes.
5. Do not leave garbage can lids upside down. Do not allow water to collect in the bottom of garbage cans.
6. Flush birdbaths and the bottom of potted plant holder trays twice a week.
7. Adjust tarps over grills, firewood piles, boats, and swimming pools.
8. Re-grade drainage areas and clean out debris in ditches to eliminate standing water in low spots.
9. Clean and chlorinate swimming pools. Aerate garden ponds and add "mosquito dunks" found at hardware and garden stores.
10. Fix dripping water faucets outside, and eliminate puddles from air-conditioners.
11. Store pet food and water bowls indoors when not in use.

Using Insect Repellents Safely

Carefully follow insect repellent label directions & precautions.

1. Use products containing DEET. The "Green DC" approach would be to try aromatic oils specifically designed as mosquito repellents.
2. Don’t apply to eyes or mouth; and apply sparingly around ears. Do not spray directly on face; spray on hands, then apply to face.
3. Do not apply to children’s hands. Apply to your own hands, then put it on the child. Wash hands thoroughly after application to avoid exposure to face membranes.
4. Apply only to exposed skin and/or clothing. Do not use under clothing.
5. Never use on cuts, wounds, or sunburn.
6. To get assistance with choosing the right mosquito insect repellent, go to the EPA-Pesticides Health & Safety/Insect Repellents: Use & Effectiveness website that provides a chart to personalize your needs.

Protect Yourself

1. Wear light-colored long-sleeve shirts and long pants.
2. Stay indoors at dawn, dusk, early evening.
3. Use fine mesh screens on windows and doors.

Protect Your Pets

1. Keep animals in the house at dawn and dusk. 
2. Avoid woods, wetlands. marshy areas.
3. Do not house your dog in heavily wooded and marshy areas.
4. Empty water bowls that are outside for your pet on a daily basis (everyday).

Mosquito Websites

"Fight the Bite" Story Map:

• The Fight the Bite Story Map uses geography to tell the story of mosquito surveillance in Washington, DC. It looks at the places, events, issues, trends, and patterns in a geographic context, combining authoritative maps with narrative text, images, and multimedia content. Please select the link below to view the Story Map containing information pertaining to the 2016-2018 Arbovirus Surveillance Program conducted annually by DC Health’s Animal Services Division. This Story Map contains 13 interactive maps, 19 sections, images and other multi-media content.

           Select this link:  Fight the Bite Story Map

Other Mosquito Websites:

• Arbovirus Surveillance, Migration and Prevention Plan 2016 
• Tickborne Diseases
• Vector‐borne Diseases: A reporting guide for healthcare providers
• CDC's West Nile Information Page

If you find a dying bird, call the DC Animal Shelter at (202) 576-6664 and a dispatcher will call an Animal Control Officer to rescue the bird.

To report a dead bird, call the West Nile Virus Call Center call at (202) 535-2323. For dead animal pick-up, call 311 with the exact location of the bird. 

If you have any West Nile Virus questions or concerns, do not hesitate to call (202) 535-2321.  Your concern will be addressed within 24 hours or the next business day.