Mosquitoes of Idaho
A feeding snowpool mosquito.
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Mosquitoes are familiar to everyone. These small delicate flies, with noticeably long legs and a "beak" or proboscis, are most persistent around humans and animals as they search for a good spot to feed. In Idaho, mosquitoes are not only "vectors of misery and discomfort," they transmit several groups of encephalitis, with West Nile virus (WNV) being of major importance in Idaho for the past one and a half decades.
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Attacked by the irrigated pasture mosquito.
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Mosquitoes are another vector that I became most interested in as a result of taking medical entomology in college and being a vector control field person as an intern with the San Jose City Health Department. Since those early years (60s and 70s), my occupation has allowed me to work with mosquitoes in many capacities. The most interesting work was assisting the Office of Epidemiology and Food Protection (IDHW) with the WNV surveillance program from 2003 to 2010.
WNV was first reported in the United States in 1999 and started moving across the country. By the end of 2002, WNV was at Idaho's doorstep. As a result, Idaho agencies prepared for the invasion by educating the public, testing mosquitoes caught in traps, determining equine illness and compiling human reports of the disease. The following graph depicts what has happened from 2003 to 2013 (data from USGS WNV disease maps):
WNV was first reported in the United States in 1999 and started moving across the country. By the end of 2002, WNV was at Idaho's doorstep. As a result, Idaho agencies prepared for the invasion by educating the public, testing mosquitoes caught in traps, determining equine illness and compiling human reports of the disease. The following graph depicts what has happened from 2003 to 2013 (data from USGS WNV disease maps):
West Nile virus activity in Idaho.
Mosquito trap.
As depicted in the graph, 2006 was a bad year in all respects. The number of human cases far exceeded any other state in the union that year. Of the 51 species of mosquitoes occurring in the state, the primary vector of WNV is the western encephalitis mosquito (Culex tarsalis). Two other Culex species have been found to be vectors of the disease, namely the northern house mosquito (Culex pipiens) and the tule mosquito (Culex erythrothorax). These and other mosquitoes are identified, sorted and the primary and secondary vectors are tested. Positive results alert mosquito abatement agencies of cells of WNV activity and additional educational and abatement activities can take place in these areas.
When outdoors during the mosquito season, mosquito contact can be reduced by wearing clothing that covers the skin, such as long sleeved shirts and long pants. Also apply effective insect repellent to clothing and exposed skin and reduce outside activity during the hours that mosquitoes are most active. The above Culex mosquitoes generally feed from dusk to dawn.
I have a keen interest in Idaho mosquitoes and investigations are continuing. The following references are provided:
When outdoors during the mosquito season, mosquito contact can be reduced by wearing clothing that covers the skin, such as long sleeved shirts and long pants. Also apply effective insect repellent to clothing and exposed skin and reduce outside activity during the hours that mosquitoes are most active. The above Culex mosquitoes generally feed from dusk to dawn.
I have a keen interest in Idaho mosquitoes and investigations are continuing. The following references are provided:
- Brothers, DR. 1969. 1969 annual report of the City-County Health Department mosquito control program. Boise, ID. 21 pp.
- Brothers, DR. 1971. A check list of the mosquitoes of Idaho. Tebiwa. 14(2):72-73
- Brothers, DR, Darsie, RF Jr. 2003. A checklist of the mosquitoes of Idaho and two new state records: Ochlerotatus dicticus Howard, Dyar and Knab and Oc. euedes Howard, Dyar and Knab. Am Mosq Control Assoc. 19(3):259-260.
- Brothers, DR. 2003. Mosquitoes of Idaho: An introductory guide to understanding them, their importance, and the control process. Boise, ID. Probes. 91 pp. (currently out of print and under revision B 1st edition available in most Idaho libraries).
- Brothers, DR. 2005. Notes on mosquitoes associated with the 2003-2004 Idaho west nile virus surveillance. Unpublished presentation. Idaho Environmental Health Association. 14pp.
- Brothers, DR. 2005. New distributional records for Coquillettidia perturbans (Walker) (Diptera, Culicidae) in Idaho. J. Vector Ecology. 30(1):163-164.
- Brothers, DR. 2008. Pictorial Key to Important Mosquitoes (Southwestern, Northern, and Eastern Idaho). IDHW. 3 posters.