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How to Control Fungus Gnats

If you enjoy having plants indoors to liven up the place, one drawback that can be rather annoying is how houseplants usually gather attention from fungus gnats. You may have had fungus gnats flying around your potted plants indoors or even gathered outside your window aching to get in. These nuisances not only can be irritating to try swatting out of your home, they can also damage plants if measures are not taken to control them.

Fungus gnats are generally small, often tiny, flies with long legs and long thin wings, similar to that of a mosquito. These gnats have vein patterns in the wings and are an 1/8th of an inch long. Gnat eggs are so small they can hardly be seen by the naked eye but are smooth and range between clear to white in appearance. During the larvae stage, gnats are legless and thread-like with shiny black heads and can be up to a 1/4th of an inch long.

Plants can be damaged by fungus gnats by them preferring to lay their eggs on the plant and eating at the decaying organic matter and fungus growing in the soil (hence their name) but they will also eat plant roots. Fungus gnats thrive in indoor environments and grow their populations to large amount mainly due to the moisture levels being ideal indoors.

If you are dealing with pesky fungus gnats in or around your home, Solutions Pest and Lawn can help you with the best products and helpful DIY advice around.

View our fungus gnat killing products below. If you have any questions or concerns, feel free to contact us and we will be happy to assist you with your order or give you helpful pest control advice.

How To Get Rid of Fungus Gnats: 4 Step Solution

The majority of the fungus gnat’s lifespan consists of mainly of the larvae and pupa stage and that is when they do the most damage to the plant and the soil that they reside in. The adult stage is short lived so the best method of control is targeting the gnats when they are in their younger stage. However, whether they are larvae or those annoying flying adult gnats we have a way to get rid of them and will share you the steps how you can rid them yourself.



Step 1: Start by inspecting indoors and see where the breeding source is. This is usually either a house plant or any area of moisture, perhaps a leak of some sort that has yet to be discovered. Fungus gnats like areas with high moisture. Make sure your containers have good drainage, and avoid overwatering your plants. Let the top 1-3 inches of soil dry before adding more water. You can even place a raw potato on the soil of your potted plant so it will soak up the moisture. Keeping the top of the soil dry will help stop fungus gnats from laying their eggs in the soil. If you have a water leak, repair it immediately. Repotting the plant in fresh soil may also help.


Step 2: Trapping is an effective method of taking care of the adult fungus gnats. Set up a trap such as the Musca-Stik to capture remaining fungus gnats in the home after moisture sources have been removed.Gnats may also be removed naturally by replacing the soil of potted plants with dry soil or removing the plant or moisture source from the home completely.


Step 3. For plants you wish to keep around that are infested with gnats, you can treat them with an insecticide such as Reclaim IT. Spray the insecticide all over the plant to kill off eggs and larvae residing on the plant. Take the plant outdoors to perform the treatment and allow to fully dry before bringing back in the home.


Step 4. If gnats are still flying around your home, use an aerosol spray like CB PCO Fogger or Pyrid Aerosol Insecticide for a fast knockdown and quick kill.


Learn More About Fungus GnatsImage result for fungus gnats

Fungus gnats are small pesky flies which look similar to mosquitoes are two to three millimeters long. However, they don’t bite or sting. Instead, they like to crawl and creep around plants and places where fungus is developing, hence their name.


Fungus gnats fly around in a seemingly erratic fashion, getting in your face, buzzing from place to place slowly and seemingly without purpose, which can be very irritating. Some homeowners and gardeners confuse them with winged root aphids, which are better fliers and have a rounder and broader body and are more attracted to lights.


There are a number of different varieties of fungus gnat but most likely when you encounter them, those uninvited guests are either from the Mycetophiliadae or Sciaridae family.



Fungus Gnats Damagepotted plants fungus gnat

Adult fungus gnats aren’t really the big issue when it comes to causing damage as they simply fly over plants, consuming only liquids and are harmless to plants. Fungus gnats can become an irritating issue though indoors when adults emerge from potted plants that have damp soil and are rich in fungus.


The fungus gnat larvae however, hatched from tiny eggs laid by the female adults in most growing media, are the most damaging phase of the metamorphosis cycle as they are the ones that cause all the issues, especially to young plants. The fungus gnat larvae primarily feeds on organic material, algae, and soil fungus but in increasing numbers, that necessitates a broader diet including roots and plant stem tissue. Yes, they nibble on your plants roots!


This is especially troublesome because the damage inflicted upon plant roots by the fungus ants because in turn, it creates wounds which opens up the gateway to secondary infections from the likes of pythium, phytophthora and fusarium. Seedling and younger plants can die from these issues while older plants could stop growing as a result. Leaves will discolor and wilt, and nutrient as well as water uptake will slow.


For these reasons alone, addressing a fungus gnat issue should be a top priority for gardeners concerned by their presence.


Fungus Life Cycle

As with all pests, you must first understand their lifecycle and disrupt it, preferably at multiple stages at once. Ignored fungus gnats can breed uncontrollably and a few weeks after spotting a handful of gnats, you’ll have a major infestation on your hands.


The life cycle of a fungus gnat takes approximately 28 days to go from egg all the way to an adult. During this cycle they go through the following stages: egg, larvae, pupae and adult. Fungus gnats can develop many generations in just the span of a year. This is because adult females can lay 30 to 200 eggs in a singly sitting or in clusters placed on the surface of growing media and in moist organic debris such as leaf litter.


Fungus gnats prefer to lay eggs right where the fungus that is attracting them is growing. Once the egg hatches, the fungus gnat larvae feeds for about two weeks then goes into a pupate stage near the soil surface. After about a week in the pupa stage, the fungus gnat emerges into an adult and lives for about 8 or 9 days.


Fungus Gnat Behaviorfungus gnat

Fungus gnats can hit a ride into your home on your clothing, through gaps between doors and walls as well as soil, compost and soilless potting mixes. Once introduced, they seek out moisture and humidity. Top feeding your plants too often created ideal breeding conditions vis moist surface growing media.


In rare instances, fungus gnats may create an infestation inside the walls of buildings where there is enough sufficient moisture to allow fungus to grow. This usually occurs in new building construction where the wood still carries a high degree of moisture. As the wood dries, the fungus gnats may leave on their own.


Indoors they may seemingly come out of nowhere and begin buzzing around rooms and flying into your face. This is usually due to having houseplants in the home which is developing fungus which lures the fungus gnat inside.

Checkout Our Other Flying Insect Solutions

Fungus Gnat Management

When it comes to eliminating a fungus gnat issues, the first step to get rid of fungus gnats indoors is to reduce the soil moisture of your house plants. You may be overwatering or do not have good drainage that is causing the fungus gnat infestation.


Allow the soil surface to dry between watering, but do not allow plants to get to the point of wilting. You may be able to observe when your plant needs more water by picking up the plant pot and feeling its heaviness. If it is feeling lighter than usual, it may require some watering. This may take a little practice before you get a good idea of the weight of the plant and being able to determine based off of that when the plant it needs water.  Another thing that may help is observing the color of the leaves. When most plants are ready to be watered, the foliage will be a bit dull and have a less healthy green color.


One of the most effective products for treating fungus gnat larvae found in the soil is an insecticide, such as EcoVia 3-in-1 Natural Insecticide. This insecticide is safe to spray on the foliage of your plants without damaging it and can sufficiently kill the fungus gnat larvae.


To address adult fungus gnats, a good control option to implement is the use of sticky traps like Musca-Stik. You can place these sticky taps in the pots themselves to help you find out which plants are the most attractive to the fungus gnats. While this can help to address the adult fungus gnat problem, it doesn’t deal with the fungus gnat larvae issue which is why we recommend using both products in tandem and not solely using one product to totally control the fungus gnats.

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