New West Roundup

Post-Flood Mosquitoes: Just How Bad Will They Be This Year?

By Matthew H. Davis, 7-01-11

	A familiar sight this summer in the Rockies, where states and counties are already announcing plans to spread pesticides. Photo by Flickr user kainet.

As flood waters recede throughout the Rockies, another problem has begun to plague parts of the region: swarms of mosquitoes. 

Several mosquito control groups throughout the region have observed an increase in the blood-sucking bugs and have taken steps to try and curb them.

Many mosquito species in the region can lay eggs that can last several years, said Joe Conlon, a technical adviser for the American Mosquito Control Association. Larvae lay in dry places, waiting for water, and when the water comes, a bumper crop of mosquitoes is often the result. Mosquitoes in some parts of the Rockies could be an even bigger problem later this summer, Conlon said.

“The mosquitoes that you find in the Rocky Mountain region are adapted to colder temperatures and elevations that you’d be surprised to see breeding,” he said. “The point is that you if you go past 10,000 to 12,000 feet, you’re not necessarily going to be mosquito-free.”

In Idaho and Montana—areas with the worse flooding this season—news of unusually high numbers of mosquitoes continues to be reported. In Canyon County, Idaho, located west of Boise, the war on the insects is just beginning, reports the Idaho Press-Tribune, and efforts began to fog and spray large areas of land in the county. Some mosquito abatement officials named the western part of the county the “West Nile Triangle,” because of the huge pest population.

Mosquito control began this week in Butte, Montana, as well, and the Montana Standard reports the county will be using the EPA-approved pesticide Malathion, but in Missoula, an area still dealing with flood waters, mosquitoes are some what of a bigger concern.

A representative of Missoula County recently told the Missoulian the increase in water would likely create more breeding sites for mosquitoes, but there was a silver lining: The western part of the state is home to only a limited number of species carrying West Nile Virus. 

In Wyoming, the Laramie River is still bringing flood warnings, and Laramie officials warned the city council of an overabundance of the pests, earlier this month.  The county began fogging efforts to control mosquitoes earlier this week.

Colorado is also seeing its share of summer mosquitoes, and the Greeley Tribune recently reported that irrigation ditches could become potential breeding grounds for the critters. In Steamboat Springs, which has experienced some of worst flooding in the state, officials are warning against the threat of West Nile, but pointed out the disease is rare in northwestern Colorado—although four deaths were attributed to the disease in the area just last year. 

A similar scenario is playing out in Utah, where the Salt Lake Tribune reports that in Juab County, mosquito control groups are spraying throughout the county and much of the state, although, the spraying of the insecticide Kontrol 4-4 isn’t coming without controversy. Juab’s Malquist family has opposed controlling the pests, saying that the insecticide is dangerous to the family health and the family’s organic garden. Officials say Kontrol 4-4 is “one of the safest products on the market,” and, although it is manmade, the active ingredient mimics a similar one found in chrysanthemums.

Matthew H. Davis is an intern for New West.

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