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Local mosquito spraying alert for Thursday, Aug. 15

Ten Longmont zones will be sprayed for mosquitoes on Thursday, Aug. 15, by contractor VCDI.
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Image provided by the City of Longmont.

This content was originally published by the Longmont Observer and is licensed under a Creative Commons license.

Longmont’s mosquito control contractor, Vector Disease Control International (VCDI), will perform adulticide fogging, weather permitting, in 10 of the 12 Longmont zones Thursday night, Aug. 15, 2019.

Longmont fogging/spraying is triggered when West Nile Virus positive mosquitoes are discovered in either Larimer, Boulder or Weld Counties and when Longmont traps exceed 150 mosquitoes. Larimer County officials confirmed the presence of West Nile positive mosquitoes in late July.

Zones to be sprayed on Thursday are:

LM-03 Jim Hamm
LM-22 Sandstone Ranch
LM-23 Longmont Union Reservoir
LM-27 Great Western/Mill Village
LM-28 St. Vrain Greenway @ Emery St
LM-31 Left Hand Creek at Creekside
LM-34 Longmont Meadow View
LM-41 Stoney Ridge/ Alpine Elementary
LM-42 Izaak Walton Park
LM-43 Rough and Ready South

The City of Longmont and VDCI provide a map through the West Nile virus webpage at that show the boundaries of predetermined spray areas. When mosquito traps exceed the 150 count threshold and West Nile virus has been detected in the Longmont area, notice will be provided on the website on Tuesdays. Spraying typically occurs on Thursday nights—giving residents 48 hours’ notice of any 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.

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 where habitat and weather conditions increase their likelihood.

VDCI maintains a database of Longmont residents that 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 calling (970) 278-9977 or visiting

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.

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

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.

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

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

Generally, the mosquito season extends from late April until mid-October, with the end usually signaled by the first freeze in the fall.

For more information about the health impacts of West Nile virus or mosquito activity in Boulder County, visit the Boulder County West Nile Virus webpage or call the Colorado Health Information Line at 1-877-462-2911. To report nuisance mosquitoes, click on “Mosquito Complaints” in the “What you Can Do” section on the webpage.