Pond Mosquito Control Guide

mosquito larvae in pond water

Summer and spring are exciting times for a pond-owner because fish are full of energy, plants are in full bloom, and flying insects like dragonflies are buzzing around.

It’s the perfect time to sit outside and enjoy an evening by your pond. However, some insects might have other plans.

Most of us have experienced a moment that has been destroyed by a pesky swarm of mosquitoes that gnaw at our necks, arms, and legs. Apart from causing itchy welts, they also transmit deadly diseases like malaria, dengue, yellow fever, West Nile virus, heart-worm in dogs, Zika virus, and Equine Encephalitis (CDC). 

That is why it is essential to read this pond mosquito control guide and take the proper precautions. 

Mosquitoes can breed in ponds when the conditions are favorable. Eggs in ponds eventually develop into larvae, but plenty of waste leftover will remain that will build into your pond. This can lead to smelly odors and sludge and increased harmful chemicals like ammonia and Nitrites.

Although issues regarding water quality could be an issue, the primary reason you’ll want to control pond mosquitoes is to stay away from annoying bites.

Unfortunately, getting rid of adult mosquitoes can be a challenge.

Since a mosquito’s lifespan is very short, the best method to eliminate them is to eliminate the larvae already in the pond that are waiting to develop rather than try and target the already flying adults. There are various methods to deal with larvae without the need for chemicals that could cause harm in your pond.

Why Would Mosquitoes be Living in a Pond

Mosquitoes are present in ponds each year in varying degrees; however, depending on the conditions in your pond, you may see less in one year and much more the following. Mosquitoes are attracted to slow-moving, stagnant bodies of water. Slower-moving streams make it more suitable for egg-laying. A poorly taken care of pond with low oxygen levels will probably have a more significant number of mosquitoes and more issues when compared to a pond with higher aeration levels.

Increasing water flow through the pond is the most effective method of preventing mosquitoes from breeding in the water. Aeration and water circulation can be accomplished by using aeration pumps, other waterfalls, and fountains. In addition, making sure that the water quality is in good shape will stop mosquitoes from calling your pond home.

Suppose you notice more mosquitoes flying around than usual. This could indicate that the pond isn’t getting enough air or water movement, or they’re coming to your pond from a nearby breeding area, which could be anywhere with standing water (EPA)

Are Mosquitos Harmful to Ponds

Garden wildlife consume mosquitoes, such as bats, frogs, and fish, and even birds eat them throughout the pond season. Like the other insect species, mosquitoes and their larvae are excellent sources of fats, protein, and nutrients (NCBI), and many animals are happy to eat them if given a chance.

Mosquitoes could potentially cause some issues in your pond.

In particular, mosquitoes may carry bacteria that could infiltrate your pond, which could cause problems with your goldfish or koi.

Fish already weak because of injuries or illness are especially susceptible to viral and bacterial diseases, and mosquitoes may further inject the water with foreign bacteria.

Additionally, mosquitoes can cause waste accumulation and may cause problems with water quality when eggs hatch and break down within the pond. At the same time, this is not a massive issue for larger ponds.  This would mainly be an issue with smaller ponds that have poor levels of filtration and aeration- which may be affected by the increase in biological waste.

Reason for Mosquitoes in Ponds

Surprisingly, mosquitoes are particular about the location of the eggs they lay. As fish ponds aren’t necessarily the ideal place for mosquitoes to breed. 

Some of the most frequent reasons for having mosquitoes in a backyard pond are:

Poor Water Quality

Poor water quality is typically an indication of stagnant water or excess nutrients, which helps create an ideal environment for larvae to flourish.  It is essential to pay close attention to water quality.

Even water that appears healthy may be suffering from an issue. Testing water two times every year is a good idea so that you can address any problems before they develop into more significant situations. 

Inadequate Pond Aeration

Mosquitoes prefer stagnant bodies of water with little movement at the surface because they are the perfect place to lay eggs and the larvae to live. If you own a natural wildlife pond with no pump, fountain, or skimmer, you have a higher chance of mosquitoes selecting your water feature as their home for the summer. Also, larger ponds may face problems with aeration because some water regions are slow-moving as they are further from the sources of water flow.

No Natural Predators of Mosquitoes

Lack of natural mosquito predators that keep the mosquito population under control could also be an issue. Bats or frogs, birds, and birds are all great mosquito killers, but certain factors might change in the surroundings that have led them to leave the area. For example, woodlands being cleared or ponds being renovated, or dramatic changes in conditions could result in mosquitoes predators moving on to find food somewhere else.

Poorly Maintained Pond Equipment 

In connection with aeration and poor water quality, pond equipment like filters and pumps that are not maintained properly is a significant factor in the increase in mosquitos. Because a blocked pond filter dramatically reduces the quality of water and creates the perfect habitat where mosquitoes can lay eggs. Filters that aren’t flowing well will have all the nutrients, and food mosquitoes require to develop into adults. 

Chemical Insecticides/Larvicides

Similar to other chemical treatments, insecticides or larvicides are to be used as a last resort and should never be employed in ponds containing fish. Chemicals can be highly effective in killing mosquito larvae but cannot distinguish between “good” and “bad” bugs and can just as quickly kill other insects like dragonflies, water striders, water bugs, and damselflies. They also can be harmful to pond fish.

The chemicals quickly penetrate tissues and can rapidly accumulate to poison fish. Frogs, newts, and amphibians are similarly vulnerable and likely die in ponds where insecticides have been used.

We strongly recommend against using chemical treatments to control mosquitoes in ponds. Mosquitoes can also become resistant to insecticides, which isn’t observed in natural remedies. We recommend that pond owners only utilize natural methods to eliminate mosquitoes from their water and avoid chemical insecticides. It will be more effective, safer, and long-lasting.

Non-Toxic Mosquitoe Control for Ponds 

Mosquito Dunks & Bits

This is one of the most effective mosquito controls that kills larvae. The mosquito dunks (also known as “donuts”) and bits are used to kill hatched larvae in the water and stop them from returning.

The products are made using a particular bacteria strain known as Bacillus Thuringiensis, subspecies israelensis (EPA) known as “BTI.” The bacteria kill the different kinds of insect larvae by producing toxins.

BTI is mainly effective against mosquitoes, blackflies, and fungus-gnats and has little influence on other living species or animals. It isn’t harmful to plants, fish, or animals and can be used in ponds in gardens with no harm to the ecosystem. All other ingredients are organic and will decompose as time passes after the active ingredients have been released.

The product is available in two forms: mosquito dunks and mosquito bits. The same strain of bacteria is used in both; however, the release method is different. Mosquito dunks were designed to kill mosquito larvae steadily and are excellent maintenance doses following water treatment with mosquito bits. Bits are quick-acting and can kill mosquito larvae in the pond within 24 hours of dosing and are therefore best employed as a kick-start for treatment and then followed by mosquito dunks every one or two months.

Mosquito dunks and bits are highly recommended for ponds with massive infestations or as a method of control to prevent larvae from becoming adults.

Increase Aeration & Water Flow

While pond aeration and water flow are not a method to directly kill mosquitoes or larvae, it’s a great way to prevent them in the first place. Mosquitoes are always looking for stagnant waters instead of moving water, so a pond with good water flow can help prevent mosquitoes. A pond pump will usually create enough water flow for smaller ponds, but for large pond mosquito control, you might need to install additional aerators.

Waterfalls and fountains are among the most effective natural aerators and make a great addition to any garden pond. A fountain pump can also get the most height of water and air circulation.

Suppose you have a smaller water feature and are concerned with energy efficiency.  A solar-powered aerator is a great option. The water movement minimizes the possibility of mosquitoes hatching eggs within the water since it is not ideal.

Air pumps can also add more oxygenation and water movement. While not as impressive as fountains, a powerful air pump could be a good option for a pond that doesn’t receive enough natural air circulation. Another benefit is that it adds oxygen to the water, essential if you have fish.

Mosquito Eating Pond Fish

For a long-lasting solution to controlling mosquitoes add fish that like to eat mosquito larvae in the water.

Fish such as guppies, rosy reds, fathead minnows, or other minnows are excellent mosquito larvae eaters and should be capable of surviving in all kinds of ponds. They reproduce and multiply according to the quantity of food they consume and eat most mosquito larvae in a couple of days. Then, continue to destroy any larvae created from eggs. This means that they won’t develop problems with the pond ecosystem.

You can put these fish species in a pond stocked with goldfish and koi without any concern. They’re not in danger of being attacked by either. Making them the ideal koi pond mosquito control method.

The mosquitoes eating fish bio-load is low, meaning there will not be any significant changes in water quality or issues with filtration.

This is likely to be one of the best mosquito larvae killer for ponds since the fish themselves are self-sustaining, and the number of mosquitoes determines the amount they consume. 

Bats… Yes… Bats

Bats are another natural mosquito predator, but they target adults. If you have a healthy population of bats living in your garden, it is unlikely that you will encounter numerous flying insects as bats make a quick job of them each evening as they begin hunting. Bats have a reputation for being “creepy,” but they’re among the most effective nature-based predators that can eat insects and helps keep the number of flies down—making our gardens more enjoyable.

Unfortunately, bats are becoming more scarce across most states due to the destruction of their natural habitats. But, there have been recent efforts to get bat populations growing. The most effective way to accomplish this is to use a certified and fully-equipped bat house to provide what they need.

You can even build a bat house yourself (pdf).

If you install the right bat house and use natural attractants, you’ll hopefully find some bats in your backyard, ready for mosquito control!

Conclusion on Pond Mosquito Control

Even if you think you don’t need any mosquito control in your pond, you will benefit from these steps.  High levels of water flow and aeration lead to a healthy pond.  And sometimes, no matter what you do, you might have some slower-moving areas, leading to mosquitoes.  This is where the dunks, bits, mosquito fish, and bats come in.  With a well-rounded natural approach, you will be able to enjoy your pond more and not have any safety concerns from mosquito bites. 

 

Last Updated on March 22, 2022 by Davin

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