Pollinator week brings mosquito board discussion

PINEDALE – Two very timely topics converged earlier this week – protecting fragile pollinators, such as bees and insects, while also managing hungry hordes of mosquitos. Both are aspects of summer but both aren’t necessarily enjoyed to the same extent.

Pollinator Week is June 20-26, and this when Sublette County districts plan summer helicopter flights to spray malathion and kill adult mosquitos.

Another part woven in is the very recent creation of a new Pinedale Mosquito Abatement District and board, with the former district dissolved after not meeting state laws and county rules. Newcomers are Josh Adams, Bob Jones and Mike Henn; Jones said county commissioners asked the three to pull together a proper program. Three others applied for board seats but commissioners appointed the three men without discussion at their May 17 meeting. 

Pollinator Positive!

To bring pollinators, mosquitos and the new Pinedale program under one umbrella for discussion, not-appointed board applicants Maggie McAllister and Linda Baker decided to address citizen concerns about potentially negative effects of malathion on pollinators with a program and roundtable discussion.

Important pollinators help fertilize fruit and vegetable flowers – bees of all kinds, butterflies, moths, flies, beetles and birds and bats. In past years, people said, the pesticide kills off or weakens many pollinators in the air at that time.

About 20 people attended the June 20 Pollinator Positive! presentation about Integrated Mosquito Management with Teton County Weed & Pest entomologist Mikenna Smith, including new board member Jones. After the program, Smith and Jones answered many questions and took comments. 

Came to learn

“I came here to see what we can learn,” said Jones, a pilot, adding he was taking what he learned back to Henn and Adams. This year, due to the district’s very recent changes, the Pinedale district will use malathion and has checked flight and spray equipment and licenses.

“We’re all legal now,” he said.

Smith outlined how integrated mosquito management works around Teton County, where the emphasis is more on monitoring wet locations and populations to use larvicide and target the insects before they leave the water. The malathion aerial treatment Sublette County uses when mosquitos become annoyances or public health risks to people and animals is called “adulticide.”

Smith called adulticide a “last ditch effort” in Teton County to control mosquitos, of which Wyoming has about 50 species. Larval control is more environmental and people friendly and specifically targets mosquitos. It is also more time-consuming, Smith said.

Staff monitor breeding habitats such as ponds, wetlands and other likely places for larval growth.


Under Integrated Mosquito Management, multiple tools are used to control mosquito breeding and growth, Smith explained. Larvae have “natural biological enemies” such as certain fish, parasites and aquatic plants but most aren’t allowed in Wyoming. Less harmful insecticides can target concentrated larval populations.

The final step is a serious pesticide – organophosphates (including malathion) and pyrethroids – that are not specific to mosquitos, she said. Smith advised using malathion at dusk “when pollinators are back in their nests” and spraying only what is needed. 

The buzz

Citizens complained about early-morning flights and lahaving ck of notice to cover plants or water. They also noted no flying insects around gardens for weeks after. Some commented on people and pets bad reactions after contact.

Jones replied mornings are convenient and quicker to spray malathion – “It’s difficult in the evenings (for a pilot) to control altitude. B, people come home and start barbecuing and you’re up there with a helicopter – you’re just asking for trouble.”

The district covers a 3-mile radius of 1,200 acres outside town limits.

In town limits, a truck with a fogger would bypass people who does not want their property sprayed, he said. In past summers, a helicopter flew low and sprayed directly over town.

In Teton County, a crew doesn’t spray or fog in subdivisions without written permission and a request from most homeowners, Smith advised. Drones and planes can fly over larger areas with larvacide, covering a 500-acre ranch in a couple of hours.

More county weed and pest districts use the adulticide pyrethrine, less toxic than malathion, she added. Baker noted Sublette County has used malathion for 41 years. Smith couldn’t think of any other county still using malathion but there might be some, she said.

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