Living With Mosquitoes

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 these 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. The Vector Index - an esimate of the risk of WNv to people, will be posted each week here as well as a weekly report that provides an overview of mosquito activity in the region and West Nile virus testing results.  

An Ecological Approach

The city monitors potential mosquito breeding sites on city-owned properties for mosquito larvae throughout the season. The city is also monitoring mosquito predators to better understand the food webs that naturally keep mosquitoes low. 

Most of the 50+ species of mosquitoes in Colorado are "nuisance" mosquitoes - they bite people, but they do not transmit disease. 

The Parks and Recreation Department uses mosquito magnets and mowing at Stazio Ball Fields and Flatirons Golf Course, to further improve player comfort at these sites.