Laramie Weather Causing High Numbers Of Mosquitoes, Hindering Mosquito Control Efforts

Jul 12, 2019

Credit James Gathany/CDC

Mosquitoes have been a nuisance in Laramie this year with higher than usual numbers. The weather has been both helping them reproduce and hindering control efforts.

The chilly, wet spring and evening thunderstorms have created a perfect breeding ground for the insect. Mosquitoes like to lay their eggs in moist areas.

Due to the increased number of mosquitoes, the City of Laramie Mosquito Control is having trouble managing the pest. The City of Laramie uses an integrated pest management program to target mosquitos in both larval and adult stages. For the larval control stage, the Mosquito Control Crew must head to bodies of water.

They use a tool called a dipper - kind of a cup at the end of a stick -to take samples from the water. If they can see mosquito larvae, they release an environmentally friendly bacteria known as BTI into the water. These bacteria specifically target and kill the larvae of mosquitos and black flies.

But while the larval controls do help, the most effective way to deal with mosquitoes is by fogging. Spraying a chemical that kills adult mosquitoes takes them out of the breeding pool, which is one of the most effective ways to reduce a population.

"For the adult mosquito control, it's been a difficult year just with conditions, because we have to be able to follow the label for being able to treat," Tyler Shevling, Mosquito Control Supervisor, said. "And the label says we need to be above 50 degrees and winds below 10 miles an hour, which has been pretty difficult in the Laramie Valley this summer."

These constraints are largely to ensure that mosquitoes are actually out during spraying, or else it's practically useless.

Shevling and the rest of the mosquito control crew are also still monitoring mosquito trap numbers, even while unable to fog regularly. The number of mosquitoes in those traps around town can indicate the total number of mosquitoes in town.

"We fog based off of trap numbers and our thresholds for those trap numbers. And right now all the traps are over, so the fogging rotation will continue until we get those trap numbers knocked down," Shevling said. "We're ready to go each evening and just hoping for better weather."

He's optimistic that they'll be able to start regularly fogging soon.

"As conditions improve, we'll get better control of the mosquitoes. We're definitely at peak or just below peak now. With the nicer conditions, we'll get more chances to get out and spray and conditions will improve," Shevling said.

In the meantime, to avoid being bitten, he said everyone should stay inside in the morning and evening when mosquitoes are most active. He also said to wear an EPA approved repellant, like DEET, to protect yourself when you are out.