How to Kill Mosquito Larvae in Water

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To eliminate your mosquito problem for good, you need to get to the source.

Mosquitoes lay their eggs in standing, stagnant water. Those eggs hatch into larvae, which is the next stage of the mosquito life cycle. If those grow unchecked, they will quickly turn into hungry, bloodsucking adult mosquitoes that will invade your home.

Article Summary:
  • Mosquitoes lay eggs in standing water that can hatch into larvae if unchecked.
  • To eliminate mosquito larvae, it’s necessary to find the source of standing water such as old tires, buckets, gutters, or even bird baths.
  • The most effective solution is to eliminate the source of standing water or use a larvicide such as Summit Mosquito Bits.
  • Larvicides can kill the larvae, but they make the water unsuitable for human consumption.
  • Vegetable oil, such as olive oil or cinnamon oil, can also be used to kill the larvae.
    • To use this method, add a teaspoon of vegetable oil to a gallon of water to smother the larvae.
mosquito larva in a pond
Mosquito larvae in a pond

Where to Find mosquito Larvae In Your Yard

mosquito and larvae

Once you recognize mosquito larvae, you will notice them everywhere. Yes, they ARE that common.

Look in any standing water (water that is still and doesnt really move) around your home. The following places are good spot to start:

  • Ponds
  • Old tires
  • Buckets or containers that are left outside
  • Gutters that hold water
  • Planters
  • Pools
  • Spas

What do Mosquito Larvae Look Like?

They are also known as wrigglers and that’s for a good reason. These cylindrical worms dangle from the surface of the water and wriggle around the water, they will do this especially when they sense danger when they will head to the bottom or a hiding place.

You may also notice that they look like they have tiny hairs protruding from their body. These hairs are actually collecting single-celled organisms for the larvae to feed on.

Learn more: The best ways to kill mosquitoes

The Most Effective Ways To Kill Mosquito Larvae

1) Use a Larvicide

Getting rid of standing water may be the easiest solution, but it’s not always practical. There are some places, like ornamental ponds, where we expect for there to be standing water.

In those cases, one solution is to use a larvicide. These are chemicals that kill mosquito larvae, leaving your water pristine.

At least, the water will look pristine. In actuality, the water will be unsuitable for human consumption. If you use a rain barrel to collect drinking water, do not use a larvicide to decontaminate it.

Mosquito Bits are the most common form of larvicide. While they’re not safe for humans, they’re perfectly safe for fish. This makes them a great choice for koi ponds and other outdoor fish habitats.

To use mosquito bits, simply drop them into your water. The instructions will tell you how many are required for a given water supply. A good set of mosquito dunks will last for 7-14 days.

2) Remove The Water

mosquito larvae in water in old tire

Perhaps the most obvious method of getting rid of mosquito larvae is simply to eliminate the water altogether. This means you have to find any sources of standing water on your property.

Look for puddles on your lawn. If there hasn’t been a recent flood or rain, puddles are a sign that you’re over-watering. Water your lawn less, and these puddles should soon disappear.

Also look for lawn equipment that has been left outside. Lawnmowers, wheelbarrows, and other similar equipment can fill with water, creating a perfect habitat.

Pool covers and boat covers are another source of stagnant water. Dump these out and dry them thoroughly. The last thing you want is to provide a free, preventable source of standing water.

While you’re at it, look for buckets, old tires, pails, and watering cans that have been left outside. If you must leave a bucket outside, flip it upside-down to prevent water from pooling.

And don’t forget to change your bird bath regularly. Bird baths are a frequently overlooked source of standing water because we expect them to be full.

3) Chlorine Bleach – Avoid

Chlorine bleach can be used as an effective method of controlling mosquito larvae, however its use is highly discouraged. The chemical has been found to be toxic to other animals, and can have devastating effects on the environment.

It is recommended that a more sustainable, long-term solution be sought instead, such as the introduction of other species that prey on mosquito larvae, or the implementation of habitat destruction to reduce the number of suitable breeding grounds.

Natural Ways To Kill Mosquito Larvae

mosquito emerging from larvae

1) Vegetable Oil

Adding a tsp of extra virgin olive oil to a gallon of water kills mosquito larvae fast. The thin oil top layer on the surface will smother and suffocate the larvae, killing them in the process. Aside from olive oil, applying cinnamon oil also works. 

To do this, you’ll simply need to coat the surface of the water with something their breathing tubes can’t penetrate. One good option is vegetable oil. Simply spray enough vegetable oil on the water that there’s a visible gloss on the entire surface.

The main advantage of vegetable oil is that it’s non-toxic. In small amounts, it won’t cause any issues with your drinking water.

That said, it’s a poor choice for fish ponds. Fish need their water to have contact with the air, to ensure oxygen exchange. If you use oil to treat your fish pond, your fish will die along with the mosquitoes.

2) Dish Soap

Another way to suffocate those baby bloodsuckers is to use dish soap. A single drop of soap is enough to treat a gallon of water. So if you have a 100-gallon pond, use 100 drops of soap.

The advantage of soap is that it’s cheap and, at these concentrations, it won’t ruin the appearance of your pond. The downside is that it’s not a good choice for drinking water or for fish.

3) Cinnamon Oil

If you’re looking for an environmentally-friendly way, cinnamon oil is a choice (although possibly an expensive one). And it doesn’t just kill the larvae; it also kills off the eggs as well.

To use cinnamon oil, add a ratio of 15% cinnamon oil to 85% water. So if you have a 100-gallon pond, use 12 ¾ gallons of cinnamon oil.

But unfortunately, with the price of cinnamon oil being quite high currently, it is unlikely to be a cost-effective option.

4) Apple Cider or White Vinegar

Apple cider or white vinegar is another effective way of eliminating mosquito larvae. It needs to be added in the same fashion as cinnamon oil, at a ratio of 15% to 85% water. Less will not work.

It’s not as effective as cinnamon oil, though. While cinnamon oil works almost instantly, vinegar takes about 18 hours to be effective.

Like cinnamon oil, apple cider vinegar is not a good choice for fish ponds. However, it’s perfectly safe for humans.

How To Kill Mosquito Larvae In Drinking Water

If mosquitoes have infiltrated your drinking water tank and laid eggs, you have a serious predicament on your hands. This is because there is no effective way to kill the larvae without also compromising the safety or quality of the water in the tank.

Luckily, dealing with mosquito larvae in drinking water doesn’t require actively killing the pests, so long as you are willing to do a little work.

1. Prevent Mosquitoes from Accessing the Water Tank

photo of a water tank

The first thing you absolutely need to do is find out how mosquitoes are getting into your tank and seal the gap. After all, if mosquitoes can get in, so can other bugs and debris which could compromise the safety of your stored water.

Do a thorough check of the outside of the tank, paying special attention to the areas above the waterline where mosquitoes would be getting in. Also, check your air vents to assure the screens are securely in place.

These screens need to be made of fine mesh with holes smaller than 1.2mm to keep mosquitoes out.

Use caulking, waterproof sealant tape, and other drinking-water-safe sealants to fill any cracks or gaps in your tank.

Note: Not only will sealing the tank keep additional mosquitoes from getting in and laying more eggs, but it will prevent the larvae inside the tank from getting out once they mature into flying adults. Without food, these adults will die soon after they emerge.

2. Eliminate Pooling Water In the Tank Feeder System

In some cases, larvae find their way into drinking water tanks not because an adult snuck into the system, but because they were swept in with rain or source water.

If water is allowed to pool in the gutters or open-ended pipes that feed your water tank, then mosquitoes may use them to lay eggs. With the next rainstorm, these eggs or the emerging larvae are swept into the tank where they continue to develop.

If you have an open tank feeder system, look for low spots where water accumulates between storms and eliminate them. Gutters should be set at a down angle at all points in the system to prevent pooling.

Once you’ve eliminated all pooling points, you should no longer have this issue.

Note: Advanced filtration systems will remove mosquito larvae and should be enough to filter and neutralize eggs. But filter screens, even very fine ones, will not be enough to capture tiny mosquito eggs and very small emerging larvae.

3. Filter the Water Before Drinking

water filters and a glass of water on the table

Once you have sealed your water tank to prevent mosquitoes from getting in (or out) and have eliminated pooling, you should no longer have issues with mosquito larvae in your water tank.

Of course, you still have to deal with the larvae already present.

Since there are no safe ways to kill mosquito larvae without making your water unsafe to consume, the best course of action here is to simply filter it before drinking. Most commercial drinking water filters will effectively capture and neutralize mosquito larvae.

If the idea of drinking dead (or possibly, still living mosquito larvae) doesn’t bother you, then you can skip this step altogether.

Note: According to Clegg’s Pest Control, mosquito larvae are not dangerous to humans in any way. This life stage of the pest does not carry any communicable diseases and will not cause harm if ingested by humans or animals.

If you’re on the other end of the spectrum and can’t imagine drinking mosquito larvae water, filtered or not, your best option is to drain the tank and use the water for your garden or livestock. As long as you’ve done a sufficient job sealing the tank and preventing pooling in the feeder system, you should not have any mosquito larvae to deal with after you refill the tank.

Preventing and Control of Mosquito Larvae in Water

There’s an old saying that an ounce of prevention is worth a pound of cure. How does this apply to mosquito eradication?

Simply put, stopping mosquitoes laying in the first place is better than killing them once they’re in place. LEts have a look at how to prevent larvae.

Related: How to get rid of Mosquitoes

Use Water Aeration and Movement

standing watear aeration

As we mentioned, mosquitoes prefer to lay their eggs in still, stagnant water. That’s why you’ll find mosquito larva in a pond, but not in a river.

To discourage mosquitoes from laying their eggs, a pump or a pond aerator is one of the best solutions. This will keep the surface of the water moving, which will drive mosquitoes away.

In addition, if there are any existing eggs or larvae in the water, it can also help kill them. This is because it makes the surface turbulent, which disturbs the larval breathing process. It’s the same reason that mosquitoes don’t like to lay their eggs in moving water to begin with.

A pump or aerator is also a great choice for fish ponds. It helps oxygenate the water, promoting strong, healthy fish.

Use Mosquito Eating Fish

koi in a pond to kill mosquitos

We’ve talked a lot about fish ponds in this article. But did you know that many species of fish can actually help prevent mosquitoes?

Several species of freshwater fish, such as koi, goldfish, bluegill, guppies, catfish, and the appropriately-named mosquitofish love to eat mosquitoes.

Adding one or more of these fish to your backyard pond can kill two birds – and many mosquitoes – with one stone. First, you’ll add an attractive touch of life to your pond. Second, you’ll get rid of your mosquito problem.

When you purchase your fish, make sure that the fish are suitable for your area. Not all fish are equally suited for all climate zones.

Reduce Vegetation

standing water and vegetation

An important part of preventing mosquito larvae is to discourage adults from coming around. The fewer adult mosquitoes in the area, the fewer you will see.

Adult mosquitoes feed in the twilight hours. But during the daytime, they shelter in low vegetation. They particularly appreciate wet areas, such as next to a pond.

By eliminating vegetation around ponds and pools, you can encourage adult mosquitoes to live elsewhere.

If you maintain flower beds, ensure that the mulch stays dry. This doesn’t mean you should avoid watering altogether. But the leaves should not be dangling down into a moist environment.


Frequently Asked Questions

Does white vinegar kill mosquitos?

Yes, white vinegar (and apple cider vinegar) will kill mosquito larvae. To be effective, you must use a ratio of 15% vinegar to 85% water.

What can I put in my water tank to kill mosquito larvae?

At this time, we are not aware of anything you can put in a drinking water tank to kill larvae that will leave your water safe to drink.

Read more about this here.

mosquito larvae in water pinterest image

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Author
Aaron is the founder of and Essential Home and Garden. With over 15 years of hands-on experience in home ownership, lawn care, and gardening, Aaron is a seasoned expert in areas like lawn care, DIY, HVAC, and pest control.

27 thoughts on “How to Kill Mosquito Larvae in Water”

  1. Avatar photo

    Just so everyone knows, I thought I could kill the larvae by squeezing juice from my lemon tree which I figured would be environmentally safe. I used about 5 medium sized lemons for our 6×4 foot empty fishpond that had about an inch of water after the rain. Nope- two days have gone by and they’re still wiggling away. I’m trying veggie oil next.

  2. Avatar photo

    I have been collecting dripping water in a large galvanized tub to use for plaster. I know soap or oil will interfere with the setting up and also with the adding of fresh plaster to already dry plaster. (they are natural separators)
    What about alcohol? Would that kill the larvae? and how much would i need? I think bleach would weaken plaster, but am not sure. What about plain white vinegar?

  3. Avatar photo

    I collect rain water in a huge plastic tub, to water my pot plants/hanging baskets instead of using chlorine city water. Mosquitoes hatch out before I use up the water. So if I use vegetable or olive oil or dish soap, would that be harmful to my plants/flowers. Sure would hate to kill them!

    • Aaron Green

      Oils or dish soap shouldn’t harm your plants at all.

  4. Avatar photo

    Cinnamon oil is around $325 a gallon! You wrote to use 12 gal. for a 100 gal. pond. If a person were to use this suggestion that you made, it would cost them close to $4,000!!! Do you really think this is an option for anyone but the super wealthy???

    • Aaron Green

      Good point Pat! I have amended the article to make it clear that it is an expensive choice.

  5. Avatar photo

    What about just a regular pool? Do I need an aerator in it to keep mosquito larvae at bay?

    • Aaron Green

      The regular chemicals in the pool should keep the mosquitoes away.

  6. Avatar photo

    new pond set. had some issues with the solar pump. now fixed. but a lot of mosquito larva. so we put oil on the pond. I would like to get some goldfish to help keep the population down. now that we did the oil, how long does it last? or do I drain the pond and add new water. wait for a few days to settle (city water) and then put fish in? help!

    • Aaron Green

      What sort of oil did you use? I would do a quick google search to find out if the oil you used is dangerous to gold fish.

  7. Avatar photo

    Are any of these solutions better for frogs. I dont jabe any fish yet in the pond but alot of frogs habe made it there home. What can i use thats frog friendly?

    • Avatar photo

      Lucky you! The frogs will feast on the mosquitoes and you won’t have a mosquito problem!

  8. Avatar photo

    I put vegetable oil in my kiddie pool I found mosquitos and larvae in is it safe to dump in the grass or dirt if I plan on planting in the dirt?

    • Aaron Green

      That should be fine!

  9. Avatar photo

    Hi, I have mosquito eggs on my lucky bamboo plant. Which of these solutions are best suited for me? I also don’t want to kill the plant but the eggs are not in the water, they are on the bamboo itself. Please reply as our house is getting a lot of mosquitoes indoor.

  10. Avatar photo

    Is it safe to use a little drop of shampoo on my water vase without hurting the plant?

    • Aaron Green

      Probably, yes. But it would depend on the shampoo.

  11. Avatar photo

    hello, i have a couple of small container water gardens. both have plants in them that do not like water turbulence (water lilies) and i don’t have access right now to dunks. ques – can i put cinnamon oil in water without hurting plants? if i don’t have cinnamon oil, can i use cinnamon sticks or powder effectively? are there any other oils i might use? many thanks for all the advice!!!

    • Aaron Green

      I don’t think the cinnamon oil will hurt your lillies, it may in fact help them.

  12. Avatar photo

    I have a barrel that gravity feeds my chicken water cups and it’s a breeding ground for mosquitoes. Would Neem oil be ok for that? It’s the bottom 2/3 of a plastic 55 gallon barrel so it’s pretty big. Or would vegetable oil he better for that application? I also have apple cider vinegar. Would it be too much ACV for the chickens if I did the correct ratio of 15% ACV to 85% water?

    • Avatar photo

      I see lots of recommendations online for 1 tablespoon of Apple Cider Vinegar (ACV) per gallon of water for chickens. The recommendation for killing mosquitoes with ACV is 15% ACV to 85% water, which I think is roughly 2.5 cups ACV in an empty gallon container and water to fill it to the top. That may be too strong a flavor for your chickens to want to drink it, but if they go for it, I don’t think it would harm them. (My own chickens devour leftover salad bits and the couple of tablespoons of ACV at the bottom of the bowl with no ill effects.) Maybe do a test with just a gallon of the chickens’ water before you dose their entire supply…

  13. Avatar photo

    Have a new plant w drainage at bottom – one of those big round pots tipped at an angle – Southwestern style. Trying to sprout seeds so was keeping moist. When I spritz mosquitos fly out. Tried houseplant bug spray. But only killed some young seedlings.
    Hoping to keep pot w cactus & wildflowers.
    Can the larvae live in moist soil?
    Any recipes for cinnamon oil?
    Will I ever be able to keep them from hanging out at in that pot? Mosquito netting?

      • Avatar photo

        Is it okay to turn off the bubbler overnight?

        • Aaron Green

          You will need to see how it goes – give it a test and see if larvae appear.

        • Avatar photo

          I kept the bubbler off last night and there are larvae this morning.

      • Avatar photo

        I have been using a 12″ diameter frying pan splatter screen to remove mosquito larvae from my rain barrels. It absolutely works! I have been using it for a week now with nearly 100% effectiveness.

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