Fungus Gnat

What it looks like

Fungus gnats are very small, dark, winged insects often found in greenhouses and around potted plants. Adults are about ⅛ inch long, with thin legs and long antennae.

The fungus gnat life cycle has four stages (egg, larva, pupa, and adult) and usually takes 2 to 3 weeks, depending on temperature. A female can lay about 200 eggs in her short 10-day life. The eggs hatch within a week into small, see-through larvae with black heads that feed in the top 3 inches of soil.

Fungus gnats like moist conditions, so not overwatering your plants can help prevent an infestation.

Damage

Adult fungus gnats spread plant diseases, and the larvae feed on plant roots. The adults also often swarm indoors, which is annoying and embarrassing.

How nematodes help

The beneficial nematodes in BioLogic's products hunt down and kill fungus gnat larvae in the soil, so they can't grow up and reproduce.

How to apply

Treat potted plants with Scanmask by watering a Scanmask solution into the soil. Apply it directly to the soil surface, then water it in.

In a greenhouse, treat the entire greenhouse or plant inventory, and treat new plants before you bring them in. Expect to see fewer adults in about 2 weeks.

See How to apply for step-by-step directions, or use the calculator on the Scanmask Spray page to see how much you need.