Getting Rid of Fungus Gnats: A Green Alternative for Interiorscapes and Potted Plants

November 28, 2016 | Common Garden Pests

Fungus Gnats: The Indoor Plant’s Enemy

Fungus gnats, small dark colored flies sometimes mistaken for mosquitoes, can be a real headache for anyone with potted indoor plants or interiorscapes. Though harmless to humans, fungus gnats feed on plant roots and can be vectors for several plant diseases. Additionally, they reproduce quickly and a small fungus gnat problem can soon escalate to a significant (and highly irritating) infestation.

The Fungus Gnat Life Cycle

A fungus gnat’s life cycle typically takes between 2-4 weeks to complete depending upon temperature. A female fungus gnat can lay up to 200 eggs in her short 7-10 day life. The eggs are laid on the soil surface, where they hatch a few days later. The fungus gnat larvae then feed on plant roots and other organic matter for about 2 weeks until they pupate. After just a few more days the adult fungus gnats will emerge.


Getting Rid of Fungus Gnats: A Natural Alternative

Beneficial nematodes, such as those in BioLogic’s nematode products, are microscopic roundworms that live in the soil and are natural enemies of fungus gnats. The nematodes hunt down and kill fungus gnat larvae in the soil, but are completely safe for people, pets and plants. We recommend our Scanmask product for killing fungus gnats in potted plants and interiorscapes. Since existing adults will die off in about a week and the nematodes will kill the next generation of fungus gnats, Scanmask is an all natural and effective way of quickly combating these pesky insects. Scanmask is available in two formulations: either as a product you spray or in a solid formulation which you apply as a topdressing. Scanmask is available in many quantities, so it is easy to purchase the amount you need depending on how many indoor plants you need to treat. Depending on the level of fungus gnat infestation, we recommend between 20,000-35,000 nematodes/square foot. It is often a good idea to treat any new plants you bring in as they can already be infested upon purchase. If you have any application questions please feel free to contact us using the Ask an Expert form on our website. Our beneficial nematode products are exempt from EPA required pesticide registration, so they are a great control option for commercial interiorscapes since no license or registration is required for application.

If you are looking for a green method for killing fungus gnats, consider using the beneficial nematodes in Scanmask!