A mosquito spraying operation Tuesday night in an unincorporated Weld County neighborhood, just outside Longmont city limits, prompted one man to raise concerns about why he and his fellow residents weren’t notified in advance of the fogging. Meanwhile, the company in charge of the fogging said it was a precautionary measure based on the number of mosquitoes trapped in the neighborhood and the ever-present risk of West Nile virus.
Charles Winter was working Tuesday in his yard in The Elms neighborhood when he saw a Vector Disease Control truck driving through the neighborhood spraying a chemical.
Winter was alarmed that no one told him chemicals were going to be sprayed throughout his neighborhood and was even more annoyed when he looked at Vector Disease Control’s spraying schedule online, and his neighborhood was added while it was being sprayed.
Vector Disease Control sent notice to Kelly Brown, the Elms Community manager, a few hours before spraying began and she said she wasn’t able to get to her email until later in the day, so the message was not relayed to residents.
The neighborhood’s homeowners association for the past 15 years has contracted with Vector Disease Control to help control the mosquito population.
The truck was spraying an adulticide, known as Aqua-Kontrol, that kills mosquitoes, black flies as well as biting and non-biting midge. According to the Environmental Protection Agency, the toxicity of Aqua-Kontrol is fairly low, especially once it is diluted with water for spraying. However, it can be harmful to humans and pets if swallowed or if gets directly into eyes.
Nicholas Bates, a program manager with Vector Disease Control, said if people see the truck coming by they should go inside and close the windows as a precaution.
“The spray hangs around in the air for an hour or so, and then dissipates,” he said. “It’s no more toxic than the bug spray you use when you go camping, and it’s very effective. By the time we come back next week, the population should be back to normal.”
Bates said the company tries to avoid spraying unless its mosquito traps capture well more than 100 mosquitoes overnight; the trap in the Elms caught more than 700.
High numbers are a concern because mosquitoes can carry West Nile virus.
“The increasing hot weather and afternoon thundershowers create favorable conditions for the Culex mosquito that carries WNV,” said Mark Wallace, executive director of the Weld County Health Department. “The public needs to be vigilant, because West Nile virus has a permanent summer presence in Colorado.”
Weld and Boulder counties and the city of Longmont don’t initiate spraying of “adulticide until West Nile virus mosquito has been confirmed in a mosquito in the three-county (Boulder, Weld or Larimer) region,” said Dan Wolford, manager of Longmont’s Pest Management Program, but the municipalities are acutely aware of the threat posed by a growing mosquito population.
The Weld County Health Department on Monday issued a news release warning residents that while the vector index used to determine human risk for West Nile infection is low and there are no reported human cases of the virus, the vector index is likely to increase in the ensuing weeks.
To protect themselves from mosquito bites, health officials recommend people observe the four “Ds:” Drain standing water around your house weekly; limit outdoor activities during dusk and dawn, dress in long sleeves and pants when in areas where mosquitoes are active, and use mosquito repellents, such as DEET or others containing picaridin, IR3535, or oil of lemon eucalyptus.
West Nile symptoms mirror mild, flu-like symptoms and typically appear two to 14 days after being bitten by an infected mosquito, according to the Colorado Department of Health and Environment. Initial symptoms can include fever, headache, nausea and vomiting, muscle aches and weakness, and rash. Those who think they are infected should see immediately see a health care professional.