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Scientific name: Arthropoda: Insecta: Diptera: Culicidae:
Common Name: Information Sheet, West Nile Virus & Mosquitoes
Photographer: E. M. Barrows
Identifier: E. M. Barrows
Additional Information: Information Sheet, Mosquitoes and the West Nile Virus
West Nile Virus and Mosquitos in the Washington, D.C., Area.
Aedes and Culex mosquitoes transmit the deadly West Nile Virus (WNV) to birds, Cattle, Horses, and Humans. There is much information on this virus in articles and on the Internet. This information sheet primarily concerns controlling mosquitoes that can transmit the virus. Since 1999, the Asian Tiger Mosquito (ATM) has been in the WDC Area. It is common in my yard in Bethesda, MD (although I take daily precautions to stop its breeding in my yard), and bites people readily if they are not protected by clothing, repellent, and other measures. Almost all mosquito bites that I get in my yard are from ATMs. Montgomery County, MD, has a very helpful Web information regarding controlling mosquitoes and reducing the risk of contracting West Nile Virus.
To control the mosquitoes in your yard, you should:
1. Remove all things (that you don’t need) that can catch and retain even tiny amounts of water where these flies can breed. You might need to drill holes in some things so that water will drain out of them. For example, the blue County plastic recycling bins have lips on them which can hold water if the bins are upsidedown. These bins can also hold water when they are upright. The Asian Tiger Mosquito is very common in the Area, and its is a main transmitter of WNV. This mosquito can breed in even tiny vessels of water, e.g., soda bottle caps and lips of recycling bins.
2. If you want to have saucers under flower pots, bird baths, or both, you should dump out their water every 7, or fewer, days before the immature mosquitoes can become biting adults. Based on a test that I ran, it takes the ATM at least 9 days to develop from an egg into a biting adult (even during very hot weather when this mosquito is likely to develop faster than in cooler weather).
3. If you have a pond, you should keep fish in it at all times if possible, and they will eat the immature mosquitoes. When I had Goldfish and Guppies in my ponds (now removed), they ate all of the immature mosquitoes as far as I could tell. Goldfish die in ponds which contain too many fallen leaves. Guppies die in cool weather (below 70 degrees F). You might be able to control all of the mosquitoes in the pond by filtering the water, keeping it circulating, using mosquito dunks, or a combination of these measures. Because I can’t always watch a pond every day and take appropriate measures, I gave up having ponds.
4. If you have gutters in which water stands, you should remove the water within 7 days of its appearance in your gutters. If you have the new closed, rounded, “nonclogging” gutters, you should make sure that no water is standing in them. This can be difficult because some kinds are bolted shut, and it can be a lot of work to unbolt them and look into them every week.
Please see “Information Sheet, Asian Tiger Mosquito” on this Website (BDWA).
Please click here for more information from Montgomery County, MD, on mosquitoes and the West Nile Virus which is from this site:
Montgomery County Department of Health and Human Services. 2002. West Nile Virus: What People in Montgomery County Need to Know. Internet file. http://www.co.mo.md.us/services/dep/Mosquito/WNV2.pdf (25 August 2002).
E.M.B. (August 2002)