Weather Forecast


Crop of mosquitoes leads to increased spraying

The recent rains haven't only watered your lawn. They've also helped hatch an annoying crop of mosquitoes, prompting the Willmar Public Works Department to launch another round of spraying this past week.It's the second time this summer already that the city has had to spray.

"When you get that amount of rain and water standing, it brings out the mosquitoes," said Ron Gilbertson, public works superintendent for the city.

A cool start to the season has meant fewer mosquitoes this June. But with moisture and warmer weather, expect Minnesota's signature insects to soon become more numerous.

Aside from their nuisance factor, mosquitoes can transmit diseases such as West Nile virus and various forms of encephalitis.

Minnesota is approaching the peak time for the West Nile virus, which is July to September. Although the majority of people infected with the West Nile virus experience mild or no symptoms, it can cause serious illness, especially among older adults. In some cases, death or long-lasting neurological damage can occur.

Unvaccinated horses also can become very sick with West Nile virus.

Last year Minnesota had four confirmed cases of West Nile virus in humans but no deaths. The cases occurred in four counties -- Hubbard, Redwood, Stevens and Traverse.

Encephalitis is much less common. A few cases of LaCrosse encephalitis are reported in Minnesota most summers, usually in the southeastern corner of the state.

Although the likelihood of being bitten by a disease-carrying mosquito is relatively small, Minnesota Department of Health officials suggest getting in the habit of taking precautions.

Wearing long-sleeved shirts and long pants can reduce exposure to mosquito bites. So can staying indoors at dawn and dusk, the times of day when mosquitoes are most likely to be feeding.

Repellents containing 30 percent DEET (10 percent for children) are considered safest and most effective.

The city of Willmar has had a mosquito control program in place since 2003. Besides spraying for mosquitoes throughout the summer, city crews also apply larvicide in the spring to stormwater ponds, holding ponds and catch basins where mosquitoes like to breed.

How often the spray is applied depends on the mosquito situation that year, Gilbertson said. "Last year we only sprayed a few times but last year it was a lot drier."

It "definitely" makes a difference in the mosquito population, he said. "You can tell when we spray. It helps."

Anne Polta

Anne Polta covers health care, business/economic development and general assignment. Her HealthBeat blog can be found at Follow her on Twitter at @AnnePolta.

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