Eliminate Fungus Gnats Once and For All

Eliminate Fungus Gnats Once and For All

Eliminate fungus gnats that are attacking your plants. Here’s how to get rid of these pesky little buggers once and for all.

Whether you’re a hobbyist or a long-time plant collector, when fungus gnats start attacking your plants, it’s annoying. Since they are tiny and fly around quickly, you might not notice them at first. Over time, however, you’ll notice the little flying insects hovering around your plants.

But don’t worry! Fungus gnats cannot bite and don’t spread diseases, they are completely harmless to humans. However, the same cannot be said when it comes to the damage fungus gnats can inflict on houseplants.

As with any insect infestation, the best way to effectively control and eliminate fungus gnats is by knowing about them.

What You Need to Know to Eliminate Fungus Gnats

Eliminate Fungus Gnats

Fungus Gnats Appearance

Fungus gnats are tiny, with the adults ranging from 1/16 to 1/8 of an inch in length. They are greyish-black and have see-through wings. And, due to their long antennae and legs, you might mistake them for mosquitos as they fly past you. On the other hand, Larvae are around 1/8” in length, and have a thin white body with a small black head.

Fungus Gnats Lifecycle

Adults have a lifespan of around a week and can lay up to 300 eggs per adult female! The females lay their eggs in the soil beneath your indoor plants. Within around 5 days, these eggs will hatch, and larvae will emerge. And then, for two weeks, the larvae will ravenously feed on your plant’s roots, then they will transform into pupae. The pupal stage will last 4-7 days, after which adults will emerge and begin the cycle again.

Eliminating Fungus Gnats

Fungus Gnats Root Damage

Damage from Fungus Gnats

In small numbers, fungus gnats are merely annoying. However, due to the high number of eggs laid per female, you can quickly have a fungus gnat infestation! As the larvae grow, they will eat the roots of your plant. This will then cause wilting, yellowing, loss of vigor, and poor growth.

The damage fungus gnat larvae can cause your plant because of their feeding habits is significant. But both the larvae and adult can also cause the transmission of several plant fungal diseases. These include Fusarium wilt and Pythium root rot. And that’s why making an effort to eliminate fungus gnats is important. Plants with a severe infestation of fungus gnat larvae can experience dampening off, and younger plants can die.

How do My Plants get Fungus Gnats?

There are two ways by which your indoor plants can get infested by fungus gnats.

One way is adult fungus gnats flying into your home and laying eggs in the soil of your plants. If you don’t have window screens, fungus gnats fly through open doors and windows and infest your plants.

The second way is by introduction. If you buy plants from nurseries and other plant sellers, you could bring in fungus gnat larvae in the soil. Once the larvae grow to adults, these adults will fly to other plants in your home and lay eggs. Also, adding outdoor garden soil to your indoor plants can introduce fungus gnat eggs or larvae to your indoor plants.

Simple Ways to Eliminate Fungus Gnats

If you have these pests in your plants, you’ll need to eliminate fungus gnats to ensure they don’t spread! Fortunately, there are simple and safe ways that you can do to control fungus gnat infestations in your home.

1. Reduce the current population

First, carefully inspect all plants that come into your home moving forward. This will help reduce the population by not introducing new insects.

Then, alongside inspecting all new plants, you can place fine mesh screens on windows near any outdoor plants you have. This will prevent adults from flying into your home and laying eggs in the soil of your indoor plants.

2. Use yellow sticky traps

Just like many other flying insects, adult fungus gnats are attracted to the color yellow. Once you know you have fungus gnats, sticky traps will capture these adults and prevent them from laying more eggs.

3. Homemade Mixes to Eliminate Fungus Gnats

There are several items around your home that you can use to create homemade anti-fungus gnat solutions.

  • Essential oil sprays. Essential oils, like citronella or peppermint, mixed with a bit of alcohol and water, make a homemade bug spray. This spray will ward off the adults and kill the larvae to ultimately eliminate fungus gnats.
  • Hydrogen peroxide. Drench the soil with a solution of one-part hydrogen peroxide to four-parts water. This solution will kill larvae on contact.
  • Capsaicin spray. Chop up a few pieces of bird’s eye chilis (or other extremely hot chili). Then, place the chopped-up chili in around 100 ml of water, making sure to include the seeds. After around 24 hours, strain out the seeds and put the solution in spray bottle. Spray the leaves and the base of your plants with the capsaicin extract.

4. Soap and cider vinegar trap

Get a shallow container and add equal parts apple cider vinegar and water. Add a few drops of liquid dish soap and stir gently. Then, put the trap near the base of infected plants, or on top of the soil, to eliminate fungus gnats.

5. Commercial pesticides

For severe infestations, you can use commercial insecticides such as AzaMax. The active ingredient is neem oil, which is a known natural insecticide. Make sure to read the instructions thoroughly and follow them carefully so the insecticide will be safe and effective.

6. Clean the soil

If you have a severe larvae infestation, there is a good chance the soil also contains fungal pathogens. So, to be safe, throw out the contaminated soil and replace it with sterile, organic garden soil.

The Bottom Line on Eliminating Fungus Gnats

Like many insect pests, fungus gnats are annoyances at best, and determinantal to your plants, at worst. However, with a little bit of effort and know-how, you can easily control infestations and eliminate these insects. If you follow our advice, you might just save your precious plants!


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