Mosquito Larvae in Your Pool? Here’s How to Get Rid of It

mosquito larvae in water

Do you see mosquito larvae in your pool? These tiny pests can easily ruin your fun in the sun and pose a health risk for you and your family. Adult mosquitoes are notorious for carrying diseases like the West Nile virus, malaria, and Zika virus. Here’s how to identify mosquito larvae in your pool and how to get rid of them.

Identify Mosquito Larvae in Pools

Pestgnome mosquito lifecycle illustration

Mosquitoes go through a dramatic transition from egg to adult in a short amount of time. The mosquito life cycle consists of four stages: egg, larva, pupa, and adult. Female mosquitoes lay their eggs in or near standing water. The eggs hatch in a few days as larvae. About a week later, the larvae become pupae, and an adult soon emerges.

Here’s how to identify mosquito larvae and pupae:

image of a mosquito larva
Mosquito larva
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  • Mosquito larvae, commonly called “wrigglers,” are less than 1/4-inch long with large heads and long, slender bodies. They hang upside down near the surface of your pool or other standing water while breathing through air tubes in their abdomen. They will wriggle downward if disturbed.
Mosquito pupae
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  • Mosquito pupae, or “tumblers,” look similar to larvae but have comma-shaped bodies. They are found floating just below the water’s surface and will rise to breathe through air tubes. Pupae look like they’re tumbling down when swimming away.

Get Rid of Mosquito Larvae in Pools

large number of mosquito larvae
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A well-maintained pool with good chemical balance, filtering, and regular cleaning generally won’t have problems with mosquito larvae. If you have identified mosquitoes maturing in your pool, eliminate them and reduce the risk of them returning with these simple steps.

Treat Water to Kill Larvae

Removing mosquito larvae from your pool is easier if you kill them first. Here are a few tips on how to kill mosquito larvae in your swimming pool.

  • Chlorine: To kill mosquito larvae, you can shock the pool. A low dose of chlorine won’t do it. However, shocking may not eliminate all the larvae, and high chlorine dosages are dangerous to swimmers.
  • Methoprene granules: A synthetic growth hormone interferes with the development of mosquito larvae. Granules are easily distributed across the water, preventing pupae from developing for up to 30 days.
  • Larvicides: Try mosquito dunks or a similar larvicide containing the Bacillus thuringiensis subsp. Israelensis (Bti). The donut-shaped tablets float in the pool and are safe for people, pets, or wildlife. Mosquito dunks won’t affect the water chemistry and are an effective, affordable solution.
  • DIY treatments: Homemade solutions for killing mosquito larvae include apple cider vinegar, bleach, or dish soap, which are probably already in your home. Remember that these may not kill all the larvae, and you must clean and rebalance the water afterward.

Clean Your Pool

After killing mosquito larvae in your pool, it is vital to remove them to prevent the accumulation of dead or decaying matter in the water, or it can cause issues with water balance and lead to the growth of harmful bacteria. Keep your pool clean and safe for swimming by removing the dead larvae with the following methods.

  • Skimmer net: This is a quick and easy way to remove larvae from the water surface.
  • Pool vacuum: To ensure the larvae are removed from the system, vacuum them to waste. Depending on the amount of vacuuming required, you may need to replace the drained water.
  • Automatic pool cleaners:  There are several types of pool cleaners, including pressure cleaners, suction cleaners, and robotic cleaners. You can purchase these at pool supply stores or online. They are available to rent in some areas, or you can hire a professional to clean and service your pool.

Run Your Filter

If you have a problem with larvae in the pool, you can run your pump and rely on the filtration system to clear them out. However, this method takes longer, and you’ll need to clean the cartridges or backwash the filter often to keep the larvae debris from clogging the system.

  • Pre-filtering method: Wrap a skimmer sock or hair net around your basket to create an additional barrier to trap the larvae and prevent filter overload. The sock or hair net can be disposed of, making this an easy and efficient solution.

Prevent Mosquito Larvae in Pools

blue solar pool cover
Photo Credit: Backyard Productions / Canva Pro / License

It’s easier to kill mosquitoes at the larva stage than to deal with the adults later. Prevention is key when it comes to keeping your small mosquito problem from becoming a big mosquito infestation. Here are some steps you can take:

  • Keep water circulating: Mosquitoes can’t lay eggs in moving water, so run your pump or filter often. Regularly clean areas of the pool that may not receive much circulation, like around ladders and steps. Also, remove any leaves or pool floats from the surface since they can hold stagnant water.
  • Maintain water quality: Keep your pool clean and chemically balanced. Maintain a free chlorine level of 1-3 ppm to prevent mosquito larvae growth and maintain pool health. Skim the surface of the water regularly to remove debris.
  • Use a larvicide: As mentioned above, using a larvicide can eliminate any mosquito larvae that may be in the water. It will continue to work for any new hatchlings while being safe for swimmers and pets.
  • Cover the pool: Use a pool cover to prevent mosquitoes from getting to the water when not in use. Depending on the type of cover you choose, you may need a pump to move puddled water off of it. This will prevent mosquitoes from laying their eggs on top of the cover (as will a fine mesh pool cover net).
  • Check your landscape: Mosquitoes breed in stagnant water, so it’s essential to eliminate any standing water sources around your pool area and yard. Look for places where water can accumulate, such as buckets, planters, and birdbaths. Regularly empty them so they don’t become a breeding ground for mosquitoes.

The Dangers of Mosquito Larvae

Besides being unpleasant to swim through, the main risk of mosquito larvae is that they develop into adult mosquitoes. Eliminating the larvae is the first step in controlling the mosquito population and the diseases they can transmit. In addition to leaving itchy bites, mosquitoes can also transmit:

  • West Nile virus: Flu-like symptoms from this virus can lead to severe illness or death in rare cases. However, 8 out of 10 people will not show any symptoms.
  • Malaria: A parasitic disease that can cause fever, chills, and flu-like symptoms. In severe cases, it can lead to organ failure and death. It can also cause recurring symptoms in some people.
  • Dengue: A virus that can cause high fever, severe headaches, joint and muscle pain, and a rash. In severe cases, it can lead to hemorrhagic fever or shock syndrome.
  • Yellow fever:  A viral disease that can cause fever, chills, headache, backache, and muscle aches. In severe cases, it can lead to organ failure and death.
  • Chikungunya: Fever, headaches, plus muscle and joint pain are all symptoms of this virus. Joint pain can sometimes last for months, but death from chikungunya virus is rare.
  • Zika virus: A virus that can cause fever, rash, joint pain, and red eyes. Pregnant women contracting the Zika virus can pass it on to their unborn child, leading to congenital disabilities.

FAQ: About Mosquito Larvae

How Long Does it Take for Mosquito Larvae to Become Adults?

It takes seven to 10 days on average, but it depends on the mosquito species and environmental conditions. Some mosquito eggs can survive without water for several months and then hatch when they come into contact with water.

Can Mosquito Larvae Survive Outside of Water?

No, even though mosquito larvae breathe air through specialized tubes, they must have standing water to survive and develop into pupae. If the water is removed or they are taken out of the wet environment, the larvae will die.

What Do Mosquito Larvae Eat?

Mosquito larvae survive off the microscopic organisms and algae present in stagnant water. Adult mosquitoes eat plant sap, fruit juices, and flower nectar. In most species, females also feed on blood to synthesize the protein to lay eggs.

When to Call a Pro

Taking preventative measures is crucial to keep mosquito larvae out of your swimming pool and reduce the risk of mosquito-borne illnesses. Don’t let these pesky pests ruin your summer fun! Take action today by contacting Pest Gnome to connect with your area’s best mosquito control experts.

Main Image Credit: ApisitWilaijit / Canva Pro / License

Raven Wisdom

Raven Wisdom is a writer with a passion for pest control, gardening, sustainable living, and making a positive impact in the world. When she's not defending her garden from critters in the wilds of West Texas, Raven can be found writing, wrangling two kids in a neurodivergent family, and supporting her local animal rescues.