Mosquito control districts might conjure images of the 1950s, when the pesticide DDT was sprayed around houses and swamps as part of an effort to eradicate malaria. Yet mosquito control continues today. In Washington, there are 18 mosquito control districts, all but two of which are in Eastern Washington. The closest is on Camano Island, a 12-square-mile district formed in 1995 after an unusually large infestation.
The Camano Island Mosquito Control District operates a small lab to identify the 20 varieties of mosquitoes found in the area.
Two of the most common types are culex and aedes.
There are about 2,700 species worldwide and 176 in the United States. Here are some more facts:
• Mosquitoes find potential feeding targets by sight, detecting infrared radiation emitted by warm bodies, and by chemical signals, such as carbon dioxide and lactic acid.
• Mosquitoes fly an estimated 1 to 1.5 mph. Salt marsh mosquitoes can migrate up to 40 miles for a meal.
• Bigger people are often more attractive to mosquitoes because they are larger targets.
• Women are usually more attractive than men because of the difference in hormones produced.
• Some research showed that a target’s movement increased mosquito biting up to 50 percent.
• A full moon increased mosquito activity 500 percent in one study.
Diseases old and new
Mosquitoes were responsible for a malaria outbreak that occurred in the 1830s along the lower Columbia and Willamette rivers, according to the Center for the Study of the Pacific Northwest at the University of Washington.
Interest in controlling mosquitoes is now most often associated with West Nile virus, which first arrived in the United States in 1999. Nationally, 390 people have been sickened by the virus this year, with the most cases reported in Louisiana, Mississippi and Oklahoma. No cases have been reported in Washington.
Protect against West Nile virus
• Make sure dwellings have properly fitted window and door screens.
• Put on mosquito repellent before going outside and wear long-sleeved clothing and pants when mosquitoes are nearby.
• Drain even small amounts of standing water around homes and yards, which mosquitoes use for breeding.
• Dead birds can signal that West Nile virus is in the area and should be reported at http://fortress.wa.gov/doh/eh/portal/ehs/odbrs.
More about mosquitoes
• Camano Island Mosquito Control District: www.cimcd1.com/cimcdhome.html
• Northwest Mosquito and Vector Control Association: www.nwmvca.org
• Wikipedia: http://en.wikipedia.org/wiki/Mosquito
• Information about West Nile virus: www.doh.wa.gov/YouandYourFamily/IllnessandDisease/WestNileVirus.aspx
• Report of dead birds: http://fortress.wa.gov/doh/eh/portal/ehs/odbrs