Mosquito spray cutback spawns furor

GRANDVIEW, Wash. – Jim Pinson remembers the days before mosquito control near his farmhouse along the banks of the Yakima River east of here.

Some summer evenings, he recalls, 20 or more mosquitoes could land on just his hand in the time it took to walk from his back door to a deck chair.

In 1992, his neighborhood annexed into the Benton County Mosquito Control District, which sprays a network of ponds just across the Yakima River from his house. A summer evening outdoors now requires a few swats, nothing more.

“We still get mosquitoes, but boy, not like we used to,” said Pinson, a retired teacher.

But now Pinson, some of his neighbors and local mosquito control officials worry that they could see an increase in mosquitoes if new spray restrictions are adopted by the state.

Citing its toxicity to fish and other wetland animals, the state Department of Ecology is considering banning the spraying of insecticides that target adult mosquitoes near rivers, ponds and lakes.

There would be clear exceptions to allow spraying in areas where diseases carried by the insects, such as West Nile virus, have been confirmed.

And spraying for larvae, considered less environmentally harmful, would continue as it is now done.

Still, the Ecology Department proposal is drawing fire here and in other parts of the state.

A public hearing last week at the Moses Lake Fire Department attracted an overflow crowd of more than 200 people.

Critics don’t want to distinguish between a mosquito with a disease and a “nuisance” mosquito, according to Angela Balint, manager of the Benton County Mosquito Control District, which stretches from the Tri-Cities into eastern Yakima County, including in and around Grandview and Mabton.

“We just want to consider all mosquitoes bad,” she said.

No matter how aggressively larvae are sprayed, some still hatch, she said.

She also believes that waiting for a positive disease test could allow mosquitoes to propagate beyond control.

The mosquito district receives about 70 requests per year for adult spraying. Often called fogging, it is typically done from the back of pickups at night. The agency has been known to fog a neighborhood in advance of outdoor weddings and even made several applications with planes last year.

In eastern Yakima County, a high water table, flood plains and prevalence of irrigation make mosquitoes an “off-the-charts” problem, Balint said.

For example, Morgan Lake, a floodwater pond northeast of Mabton managed by the state Department of Fish and Wildlife, had mosquito counts 25 times a typical comfort level some nights last year, Balint said.

The areas around Grandview, Mabton and Prosser also are hot spots for West Nile virus.

The disease infects horses, birds and people. In 2009, 38 people contracted the disease statewide. Of those, 21 cases were in Yakima County and nine were in Benton County.

Still, West Nile virus is relatively minor and rare, said Gordon Kelly, director of environmental health for the Yakima Health District.

He said the Ecology Department’s proposal will have a “minimal effect” on the spread of the virus.