Weekly Update – June 10th – Mosquitoes are Starting to Emerge
June 17, 2025
NMCAW: Meet Sean Ford, a Catch Basin Technician from our St. Paul Facility!
June 18, 2025
All species of mosquitoes require stagnant water in order to survive in their larval stage. In Minnesota, we have different species of mosquitoes whose eggs hatch in different types of habitat. The most common mosquitoes are in the "floodwater" family and they lay their eggs on the edge of a body of water where they will remain until rain or snowmelt raises the water level and hatches them. Another family of mosquitoes are "standing water" breeders and they are not as dependent on rain to thrive. These species, like those in the Culex genus - the local vector of West Nile virus, find any source of stagnant water - naturally-occurring or human-made - and lay their eggs directly on their surface in a single raft that will then hatch 1-2 days later.
MMCD has mapped over 90,000 breeding sites for all kinds of mosquito species. Our field staff check parks, neighborhoods, wetlands, and more locations that are known to breed mosquitoes. However, we cannot be in every backyard and so during this National Mosquito Control Awareness Week we want your help to reduce mosquito breeding in your community.
Here are 10 common mosquito breeding sources that you may have in your own backyard along with our recommendations for how to remove them:
MMCD focuses on controlling mosquitoes in the larval stage. You can help by removing sources of standing water in your yard.
10 Places That Breed Mosquitoes
1) Waste Tires
PROBLEM: Tires that are left outside collect rainwater which becomes warm and murky and creates an ideal habitat for mosquitoes. Mosquitoes that can carry La Crosse encephalitis or West Nile virus are often found to have originated in tire piles.
SOLUTION: MMCD has a free tire recycling program for residents of the District. We can remove up to 20 tires per household at no cost. Check out our Tire Recycling page for more information.
If you live outside of the District, contact your county environmental center or recycling center to learn about your options for removal.
2) Landscape Ponds
PROBLEM: Decorative landscape ponds can add some nice visual appeal to your backyard, but when not properly maintained the water may become stagnant and filled with bacteria that mosquitoes thrive on.
SOLUTION: Mosquito larvae can only survive in stagnant water with nothing to break the surface tensions. Disrupting the stagnancy will prevent larvae from developing. Another option would be to stock the pond with fish who could eat the mosquito larvae. You could also replace the water with fresh, clean water every week. If none of these are available, consider purchasing larval control dunks that can be used regularly.
3) Bird Baths
PROBLEM: It's great to provide our feathered friends with a place to cool off on these hot days, but bird baths can quickly become dirty and filled with debris and bacteria that mosquito larvae will use for food.
SOLUTION: The simplest solution is to rinse out the bird bath and replenish it with clean water every couple of days. The birds will appreciate it and mosquito larvae won't have enough time to develop into biting adults.
4) Loose Tarps
PROBLEM: We set out tarps to protect items in our backyard from getting wet, but the tarps themselves can becomes sources of standing water. Our field staff regularly report finding tarps that are holding mosquito larvae because water has been able to pool on top.
SOLUTION: Tighten all of your tarps to ensure the water falls off of them and does not collect. After every time it rains, check your tarps to ensure there is no water and dump any that you find. If you are going to be away for some time, have items that are covered in tarps removed from your yard so they don't create a problem in your absence.
5) Planters
PROBLEM: Planters are one of those sources where you actually want water to help grow the plants they hold. However, the water that overflows or is left behind when a plant is removed can become a problem and create a welcome habitat for mosquitoes to lay their eggs.
SOLUTION: Check your planters several times a week to see if water is pooling at the bottom. When a planter becomes empty, store it in a covered area where it won't be able to collect water. Also, consider drilling holes in the bottom of planters so the water isn't allowed to collect.
6) Neglected Pools
PROBLEM: Nothing beats a refreshing dip on a hot day and there's nothing wrong with filling up a kids pool and letting them swim. However, if those pools stay out for days or weeks, they can become a problem.
SOLUTION: This one is simple - don't let pool water sit for too long! When the kids (or adults, we don't judge) are done swimming, empty the water into the grass or sidewalk (preferably not down the storm drain).
7) Rain Barrels
PROBLEM: This is another example of something in your yard, where you want water to be. However, if left uncovered and unmanaged, rain barrels can welcome in mosquitoes to lay their eggs and become a problem.
SOLUTION: If you have a rain barrel in your yard, it's important that you use a screen or mesh cover to prevent mosquitoes from being able to enter and lay their eggs. Check with the manufacturer of your rain barrel to see if they offer one and if not, find a cover online.
8) Tree Holes
PROBLEM: When a branch falls off of a tree or just from age and decay, holes may develop in tree trunks. These can collect water that becomes hospitable to mosquito eggs. The species that carries La Crosse encephalitis (Aedes triseriatus) is also known as the "treehole mosquito" because of its proclivity to develop in this type of habitat.
SOLUTION: Fill tree holes with dirt or sand to prevent water from pooling. In some instances you can also use spray foam or cement. Check with an arborist to find the best solution for your species of tree.
9) Wheelbarrows and Garden Equipment
PROBLEM: You dig out all of your gardening tools and equipment to turn your yard into a sanctuary. Once the work is completed, it's too hard to get everything back into its winter storage state, so you find a tucked away place and leave them out. The rain comes, then the stagnant water, then the mosquitoes.
SOLUTION: Flip over wheelbarrows, check for buckets and containers after every rainfall, keep equipment like wheelbarrows away from areas where they can be exposed to rain.
10) Clogged Gutters
PROBLEM: Cleaning out gutters is often thought of as a spring and fall activity, but if reducing mosquitoes is a goal, then it's something that should be done throughout the summer. When gutters aren't flowing and get stopped up, they create mosquito habitat that can be hard to check and remove.
SOLUTION: Clean your gutters! If going up and down on a ladder and digging muck out of the gutters doesn't sound appealing, you could purchase gutter covers or devices that block debris from settling in them.
Taking steps to eliminate these common mosquito breeding sites will help not only you, but also everyone who lives in your community. Spread the word so that your neighbors take the same steps and everyone will benefit from fewer bites and a lower risk of mosquito-borne disease. Use National Mosquito Control Awareness Week to help spread the word!
Check out the MMCD Resident's Guide for more tips to reduce mosquitoes.
