Mosquito spraying in Longmont has ended for the 2020 season. Thursday, Aug. 27, was the last date that spraying was conducted.

West Nile Virus-positive mosquitoes were identified in Fort Collins, located in Larimer County, on July 27, which led to spraying in Longmont beginning July 30. Spraying took place weekly on Thursday nights through late August.

The City of Longmont worked with mosquito control contractor Vector Disease Control International (VCDI) to combat mosquitoes that might carry the West Nile Virus (WNV). The City’s mosquito control strategy focused on mosquito disease control and not nuisance mosquitoes, first attacking mosquitoes in their larval stage before they became airborne, followed by fogging, or spraying, areas with high levels of adult mosquitoes.

“Eliminating mosquitoes before they hatch is the best way to fight the spread of the West Nile Virus,” said Dan Wolford, City of Longmont Land Program Administrator. Wolford manages the West Nile Program for Longmont. “Attacking mosquitoes in their larval stage is one of the City’s integrated pest management strategies that eventually minimizes the amount of fogging needed later for airborne, adult mosquitoes.”

Some data about WNV-positive mosquitoes and human cases in 2020:

• Thirteen human WNV cases were reported this year by Colorado Department of Public Health and Environment (CDPHE) in the following counties: Boulder (1), Larimer (3), Delta (7), Denver (1), and Jefferson (1).
• Boulder County recorded five WNV-positive mosquitoes this year out of a total of 114 samples. At least 3 of these WNV-positive mosquitoes were from the Longmont trapping area.
• The total number of mosquitoes for 2020 were above average while the number of Culex mosquitoes, which are the variety that carry WNV, was recorded below average.
• Total miles of adulticide spraying in 2020 was the lowest in history of the City’s program (which began in 2003) at 166.77 miles. (The highest level, 428 miles, was recorded in 2017.)
• The City of Longmont spent $73,944 to administer its mosquito control strategy in 2020.

Although the risk of being infected with West Nile Virus has abated for 2020, Boulder County Public Health and Longmont officials still encourage residents to take necessary precautions to protect themselves. Keep safe and remember the 4Ds:

• Defend against bites by applying insect repellent sparingly to exposed skin
• Dress in long sleeves and pants
• Avoid outdoors from Dusk until Dawn
• Drain standing water where mosquitoes breed

To learn more about the City of Longmont’s mosquito control strategy, visit LongmontColorado.gov/westnile or call 303-651-8416.

For more information about the health impacts of WNV or mosquito activity in Boulder County, visit the Boulder County West Nile Virus webpage or call the Colorado Health Information Line at 877-462-2911.