Mosquitoes are an important part of wetland ecosystems. The larval stage feeds on algae, microorganisms, bacteria and other debris. Mosquito larvae are also the foundation of aquatic ecosystem food webs, and are fed on by beetles, bugs, dragonfly larvae, fish and many other predators. Once mosquitoes emerge as adults, they provide food for birds, adult dragonflies, frogs, bats and many other animals. Adult mosquitoes, both male and female, also feed on flower nectar and some species are pollinators. Only the adult female mosquito takes a blood meal to provide protein and nutrients for her eggs.
Mosquitoes also breed in many man-made and artificial sites, like old tires, stagnant pools of water, birdbaths, clogged gutters and depressions in over-watered yards. The best way to eliminate mosquito breeding in those cases is to drain standing water. It's important for all of us to take the personal responsibility to reduce mosquito breeding habitat on our properties and protect ourselves from mosquito bites.
Avoid mosquito bites and keep mosquito numbers in check in residential areas
Living with mosquitoes is a fact of life during the summer. But we can all reduce the odds of getting bites and being exposed to West Nile virus by eliminating mosquito breeding sites in our yards to protect our and the community's health.
Follow these tips:
- Use insect repellent that contains lemon-eucalyptus oil, Picaridin, DEET or use two percent soybean-oil products (more information)
- Avoid the outdoors at dawn and dusk when mosquitoes are most active
- If you're outside when mosquitoes are active, wear long sleeves and pants
- Drain standing water around homes (pool and hot tub covers, wheelbarrows, tarps, lawn ornaments, flower pots, trash cans, toys, etc.). Change the water in your bird bath every 4-5 days. Make sure your rain gutters are clear and that water is draining
- Repair holes in your window screens and make sure they fit tightly to keep mosquitoes out of your house
West Nile Virus and Mosquito Management
See this fact sheet to learn about the risk of getting West Nile Virus and the steps you can take to reduce that risk.
The main objective of the city's West Nile Virus Management Plan is to reduce the risk of human West Nile virus infection, while minimizing environmental impacts. There are many species of mosquitoes in Boulder, but only three - Culex tarsalis, Culex pipiens and Culex erythrothorax - are known to transmit or vector West Nile Virus.
A grid of adult mosquito traps are placed around the city and monitored weekly from late May through mid-September to determine the numbers of Culex mosquitoes and samples of mosquitoes are tested for West Nile virus infection.
Focus on Mosquito Larvae
The city monitors potential mosquito breeding sites on city-owned properties for vector mosquito larvae throughout the West Nile virus season (May through September). Whenever Culex larvae are found, the site is treated with a biological insecticide, Bacillus thuringiensis israeliensis (Bti) to kill them. The Bti product is made from a naturally-occurring bacterium and has fewer impacts to the environment than other mosquito control agents.
Nuisance Mosquito Program
Most of the 50+ species of mosquitoes in Colorado are "nuisance" mosquitoes - they bite people, but they do not transmit disease. The City of Boulder treats limited sites to reduce the number of nuisance mosquitoes around several popular recreational areas and the Greenbelt Meadows and San Lazaro neighborhoods.
Sombrero Marsh, Burke II and the Kentucky Property, and wetland areas within Flatirons Golf Course, Boulder Reservoir, Stazio Ball Fields, East Boulder Community Park, Pleasantview Soccer Fields, Valmont City Park and Christensen Park are treated for nuisance mosquito larvae.
The Parks and Recreation Department will continue to employ other controls, including mosquito magnets and mowing at Stazio Ball Fields and Flatirons Golf Course, to further improve player comfort at these sites.
Review of the City's Mosquito Management Program
The city is currently reviewing and updating the city's mosquito management program. Please see this City Council Information Packet memo to learn more about the process and timeline. More information will be posted as the review progresses, as well as opportunities for public feedback and engagement.
Presentation and Open House - City of Boulder's Approach for Mosquito Management
Wednesday, June 6 ♦ 5:30 - 7:30 p.m. ♦ Boulder Public Library Canyon Theater
Join City of Boulder ecologists for a public information session on Wednesday, June 6, at the Canyon Theater to help community members understand the city’s current and future strategies for effective mosquito management and how the community and the city can partner to reduce nuisance mosquito bites and decrease the risk of West Nile virus.
Fun and surprising facts about mosquitoes, the truth about some common myths, and how the community can get involved in the city’s assessment of its current mosquito program will be included in the program.
5:30 – Presentation
6 – Q&A panel with city ecology staff
6:30 – 7:30 p.m. Open House