“Gnat” is a catch-all term for the small, persistent flying insects that multiply rapidly in your home.
When people complain about gnats, they are usually referring to fungus gnats, drain flies, fruit flies, and phorid flies.
Undoubtedly, the most harmful gnats found in the home are fungus gnats – but the good news is that, although they are annoying, they are not harmful to humans.
However, when fungus gnats are breeding in your houseplants, they can be tough to eradicate, and, if left unchecked, their larvae can destroy your prized plant’s roots.
Read on to find out how to tell which kind of gnat you’re dealing with and how to get rid of gnats in your home for good.
How to Identify Fungus Gnats
If you see a hoard of black gnats buzzing around your potted plants, chances are you are dealing with a fungus gnat infestation. In a greenhouse situation, they can be a nightmare to control.
Adult fungus gnats are around 2.5 mm long, and they look like tiny mosquitoes. You can tell if a flying insect is a fungus gnat or a shore fly (another common greenhouse pest) by looking at the insect’s antennae and watching its behavior.
A fungus gnat’s antennae are longer than its head, and they are not strong fliers. Usually, you’ll spot them flying close to a plant’s soil or running on the surface.
The Damage Fungus Gnats Cause
Although severe damage to plants usually happens in a greenhouse situation, they can damage all of your houseplants. It’s not the adults – however annoying – that cause damage, though; it’s the larvae.
The lifecycle of a fungus gnats progresses through four stages: egg, larvae, pupa, and adult. Adult fungus gnats lay their eggs in moist soil, which then hatch and feast on a plant’s roots.
The damage fungus gnat larvae cause to roots will stunt a plant’s growth, and it can kill even the toughest indoor plant.
How to Get Rid of Fungus Gnats
Fungus gnats lay their eggs in soil with a high ratio of organic matter – like compost, peat moss, and worm castings – but they are exclusively attracted to the soil’s moisture content.
The best way to prevent fungus gnats from infesting your houseplants is to avoid overwatering the soil.
Once an infestation takes hold, fungus gnats can quickly spread to your other houseplants – so always quarantine any plants you bring home by keeping them away from your other plants until you’re sure they aren’t carrying any pests.
To get rid of adult fungus gnats, you can purchase yellow sticky glue traps designed to attract them; however, getting rid of the larvae is more complicated.
The most effective way to eliminate fungus gnat larvae is to correct your plant watering habits. You can do this by ensuring that the soil of your plants has dried to around an inch below the surface before watering again.
If the fungus gnat infestation is severe, consider calling in a professional exterminator to apply a pesticide designed to kill them once and for all.
