Despite a downward trend in the overall mosquito population, Culex mosquitoes, the breed that transmits West Nile Virus, remain at historically high numbers in and around Longmont. As a result, the City will spray four local neighborhoods to protect residents from contracting the virus. In keeping with Longmont’s West Nile Virus control plan, the City’s mosquito control contractor, Vector Disease Control International (VDCI), will spray to eradicate mosquitoes on Thursday night, September 2, weather permitting. If necessary due to weather events, fogging will continue on Friday night, September 3. Spraying typically begins around 7 pm and ends at approximately 11 pm.

Four out of 12 regular zones in Longmont will be sprayed this week:

• Union Reservoir  (LM-23)
• Great Western/Mill Village (LM-27)
• St Vrain Greenway at Emery St. (LM-28)
• Izaak Walton Park (LM-42)

Please see the City’s mosquito control zone map for further location details.

Transmission risk to humans is very high due to hot temperatures and ample thunderstorms, which foster an abundance of Culex mosquito species. Additionally, residents and HOAs are asked to check their irrigation system settings to avoid overwatering. 

Managing Mosquitoes and Preventing the Spread of West Nile Virus

Longmont fogging is triggered when West Nile Virus positive mosquitoes are discovered in Larimer, Boulder or Weld Counties and when Longmont traps exceed 150 mosquitoes per trap. Boundaries of the predetermined spray areas can be seen on a map provided by the City and VDCI on the West Nile Virus webpage. When the triggering events occur, notice is provided on this webpage on Tuesdays that spraying will occur later that week – typically on Thursday evenings — giving residents 48 hours’ notice of any spraying.

Boulder County Public Health and Longmont officials urge residents to take necessary precautions to protect themselves. Keep safe this summer, and remember the 4Ds:

1. Use DEET-enhanced insect repellent or alternative.
2. DRESS in light colors and loose fitting long sleeves and pants,
3. Avoid the outdoors from DUSK until DAWN.
4. DRAIN standing water outside your home.

The City of Longmont has contracted with VDCI to implement an “integrated pest management program” to combat mosquitoes that might carry the West Nile Virus. This program focuses on first attacking mosquitoes in their larval stage before they become airborne. This is the best method since it eliminates mosquitoes before they hatch. This method also minimizes fogging to kill the adult, airborne bugs. However, some localized spraying becomes necessary when the West Nile mosquito population increases due to habitat and weather conditions.

VDCI uses state-of-the-art technology, calibrated application timing, and least-toxic products to minimize non-target impacts. All adult mosquito control is accomplished using Ultra Low Volume (ULV) fogging equipment and is performed after dusk when the majority of mosquito species are most active.

Residents Can Receive Notifications Related to West Nile Virus

VDCI maintains a database of Longmont residents who have made notification or shutoff requests for their property if spraying is scheduled. There are three options:

1. Call Notification Only: VDCI will phone you before spraying in your neighborhood
2. Address Shutoff Only: VDCI will shutoff the spray machine while driving past your property
3. Notification & Shutoff: VDCI will phone you before spraying in your neighborhood and shutoff the spray machine while driving past your property

Please contact VDCI to make a notification or shutoff request by visiting the VDCI website. Those without internet access may call 303-466-1892; however the online request form is the best way to insure that your request is processed in time for the scheduled spraying.

The City also offers an eNotification system that provides residents with up-to-date information on a variety of topics including West Nile Virus. Visit the eNotification subscription page to sign-up and choose the West Nile category to receive notification when Local Spraying Alerts are issued.

General Info on West Nile Virus

WNV is transmitted to humans from the bite of an infected female mosquito. While most infections are mild, the more serious infections can cause encephalitis (inflammation of the brain) and/or meningitis (inflammation of the brain’s lining), loss of vision, paralysis, coma, tremors, convulsions, and death.

Symptoms of WNV include fever, extreme fatigue, headache, body aches, and occasionally can also include skin rashes and swollen lymph nodes. Generally, symptoms appear 3 to 14 days after being bitten by an infected mosquito. Anyone who experiences these symptoms should consult their health care providers. There is no treatment, cure, or human vaccination for the virus. Health care providers can only treat the symptoms to help patients feel better and possibly recover more quickly. Generally, the mosquito season extends from late April until mid-October, with the end of the season usually signaled by the first hard freeze in the fall.

For more information about West Nile virus, mosquito activity in Boulder County, or proactive steps to take, visit Boulder County’s West Nile Virus information webapge or call the Colorado Health Information Line at 1-877-462-2911. To report nuisance mosquitoes, click on “Report Mosquito Activity” in the “What You Can Do” section on the website.

Learn more about West Nile Virus, the City’s integrated pest management program and how to protect yourself from West Nile Virus at on the City of Longmont’s West Nile Virus webpage or by calling 303-651-8416.