Some Colchester residents have asked the town to consider spraying to tamp down the mosquito population, logging about a dozen complaints about the pests already this season.

But the town government released a statement reminding residents it can’t spray for what are defined as nuisance mosquitos, and more aggressive control isn’t in the budget.

Colchester would have to create its own mosquito control district and would be responsible for all parts of the process, including applying for permits, hiring workers, implementing pest management practices and more, a memo to the selectboard reads.

There are currently only two mosquito control districts in the state of Vermont: The so-called BLSG, which covers Brandon, Leicester, Salisbury, Goshen and Pittsford; and Lemon Fair, which includes Bridport, Cornwall and Weybridge.

“The formation of an MCD would create an ongoing expense for Colchester (and our taxpayers) with little supplemental funding from the state,” a town press release reads. “This is not an item for which the town has budgeted.”

Patti Casey, groundwater protection specialist with Vermont Agency of Agriculture, said the creation and upkeep of an MCD is a lot of work.

“You need certified pesticide applicators, you need to maintain your certification every year, you have to have insurance,” Casey said. “It’s a financial commitment.”

Some community members have advocated for using the 1 percent local option tax to fund an MCD. However, Sarah Hadd, director of planning and zoning, said those funds are limited to voter-approved capital projects only, like construction.

“We don’t have money to spend on projects that are not budgeted for or allocated for by the selectboard,” Hadd explained.

In a memo to the selectboard, wastewater official and health officer Denise Johnson-Terk wrote that although municipalities can control nuisance mosquitoes, the Vermont Department of Health takes care of “vector” species that may carry diseases like West Nile Virus or Eastern equine encephalitis.

Natalie Kwit, doctor of veterinary medicine with the Vt. Department of Health, said the state has a response plan that includes public education, monitoring and response if necessary. The department tests trapping sites for West Nile and EEE weekly, she said.

If a large outbreak occurs with imminent risk to humans, the VDH will consider widespread spraying for adult mosquitoes, the plan says. The department’s 2017 annual report says 2.1 percent of mosquito pools tested positive for West Nile virus, but EEE wasn’t present. Neither virus has been recorded this year, Kwit added.

Costs might not be the only concern when it comes to spraying pesticides to control mosquito populations.

Last month, the Vermont Department of Environmental Conservation permitted the BLSG to spray malathion and permethrin – pesticides known as adulticides – over aquatic areas to control mosquitoes.

Some residents and environmental groups are fighting the permit, however, citing human and landscape health concerns.

When it comes to mosquito management, the EPA suggests “integrated pest management,” involving preventing mosquitoes from laying their eggs and protecting homes from mosquito entry. If pesticides are needed, the EPA suggests using larvicides and adulticides to kill the pests at different life stages.

According to the EPA, larvicides aren’t toxic to humans and are minimally or not toxic at all to wildlife like honeybees. However, adulticides, which affect the nervous system of adult mosquitoes, raise other concerns.

The National Pesticide Information Center lists malathion as toxic to beneficial insects like bees, fish, birds and other aquatic life. The adulticide also moves through soil quickly and can accumulate in surface waters.

Permethrin is known to be extremely toxic to pollinators, as well as fish and other aquatic species, and should be kept away from bodies of water, according to the Pesticide Information Project at Cornell University.

MCDs must apply for five-year permits with the Vt. Agency of Agriculture to use larvacides, but anyone with a certification in pesticide application can spray adulticides, said Casey, the groundwater specialist.

Even with its nighttime spraying, the BLSG warns residents to avoid exposure by staying inside with closed windows, washing fruits and vegetables and bringing pets and children’s toys inside at night.

While Colchester won’t see a mosquito control district any time soon, planning and zoning’s Hadd says residents can do things on their property to help curb mosquito outbreaks.

“Turn over buckets, drain rain barrels or put a mosquito dunk in them,” Hadd said. “There are simple things you can do to avoid standing water around your house.”