Big mosquito season looms

This summer will likely be a big year for mosquitoes, the county's mosquito program director says.

"It's going to be a bad year, I'm not going to try to fool anyone," Bruce Gunderson said.

Conditions are nearly perfect for prime mosquito growth, Gunderson said, because there's so much water everywhere.

Gunderson said the last really bad year for mosquitoes in the county was 2008 and this year could rival or best it.

Fields and open land throughout Flathead County are covered with water this year, which is not normal.

"We're seeing water in areas where we haven't seen water for quite some time," he said.

Mosquito eggs can lay dormant for up to five years, Gunderson said, waiting for ideal hatch conditions. "So I expect this year we'll see five years' worth of hatch."

And not only does more water allow for more eggs to hatch, it creates more habitat for eggs to be laid and to sit waiting for another year to hatch.

The missing ingredient so far this summer, he said, is the sun. Because there have been few warm sunny days, not many mosquito eggs have hatched. Once it warms up, the pests will be thick, he said.

The two development stages for mosquitoes, from eggs to larvae and then from larvae to adults, are affected by temperature.

"We haven't seen a lot really warm days to boost the hatch," Gunderson said.

Gunderson and his crew of two seasonal workers "are doing everything we can to get out there and be effective.

"We know people have had a long winter and spring and we are trying to provide for a decent summer," he said, "but it will be a real challenge."

The county uses "various forms and variations of larvacides" to control mosquitoes, Gunderson said. All of the larvacides used are environmentally safe, he said.

The department's policy is to try to kill immature mosquitoes, not adult mosquitoes.

"We can kill more using the larvacide than we can using the adulticides," Gunderson said. "It's easier to hit a stationary target than a moving one."

Mosquito spraying doesn't occur in the county.

A key part of the county's battle plan in most years is the placement of larvacide along river banks, Gunderson said. So far this year, that hasn't been possible, and may not, he said.

"We're not able to get in the rivers and do the work we'd like to because of the high water," Gunderson said. "We may entirely miss any opportunity to do anything along the rivers."

With river banks sloughing off and logs floating down rivers, safety concerns are high.

Rivers are the biggest producers of mosquito habitat in the county, Gunderson said. The larvacide can't be placed in the rivers, and the additional river water this year creates more habitat for eggs, Gunderson said.

There's one tiny bit of good news in high rivers, though, in that some mosquitoes will likely be washed downstream.

Because of the inability to work the rivers, the staff is focusing on outlying areas of emerging groundwater, Gunderson said. With the water table throughout the county so high, new lakes and bodies of water are emerging. Some of the trouble spots are in Evergreen and the Lower Valley, but really, he said, the entire county is pretty wet.

"There are little pockets all over the valley that are producing larvae," Gunderson said.

Thirteen species of mosquitoes live in Flathead County, Gunderson said. Two of them, which constitute 2 percent of the county's mosquito population, are capable of carrying the West Nile virus. Those two species "like a specific habitat that is unrelated to our flooding," he said. The two species like "more permanent water," than temporary water sites, including the bottoms of uncovered boats and tires. The other 98 percent of the local mosquitoes are the "nuisance" varieties which come off rivers and out of pastures.

People who think their property is especially populated with mosquitoes are asked to call the mosquito control office at 751-8145. Gunderson or another employee will visit the spot and determine what to do.

He reminds people of the standard efforts to protect themselves against mosquitoes:

• Wear long-sleeved shirts;

• Get rid of any standing water on your property;

• Keep screens and windows in good repair to keep the bugs outside;

• Wear a mosquito repellent when outdoors.

Reporter Shelley Ridenour may be reached at 758-4439 or sridenour@dailyinterlake.com.