Fungus Gnats

Fungus Gnat Control & Identification

Latin Name

Fungus gnats belong to the families Sciaridae and Fungivoridae


What Do They Look Like?

fungus gnat image
  • Larvae: The larvae of fungus gnats are legless and have transparent bodies with black head capsules.
  • Pupae: Pupae are difficult to see without the use of a magnifying glass. They are stout and dark in color.


How Did I Get Fungus Gnats?

Damp houseplant soil is a fungus gnat larvae’s ideal habitat, though bright lights and warmth also attract them. Infestations are common in potted plants kept outside during warmer months. When homeowners bring them indoors in the fall, the insects are more obvious within the enclosed space. The insects may also show up in water-damaged areas between walls or floorboards.

How Serious Are Fungus Gnats?

A fungus gnat breeds rapidly, and large swarms cause distractions around the home or office. The pest’s full lifespan is only about 17 days, but one female can lay over 200 eggs in that time. Because fungus gnats are extremely small, their presence can go undetected until previously healthy plants show signs of wilting and disease.

Plant Damage
While fungus gnats do not bite people, their larvae feed on mold and fungi found in soil, plus plant roots, leading to wilting. When infested with fungus gnat larvae, plants show signs of stunted development. Gnat larvae also carry plant pathogens and make plants highly susceptible to various plant diseases.

How Do I Get Rid of Fungus Gnats?

What Orkin Does
Your local Orkin technician is trained to help manage fungus gnats and similar pests. Since every building or home is different, your Orkin technician will design a unique program for your situation.

Orkin can provide the right solution to keep fungus gnats in their place…out of your home, or business.

What You Can Do
The use of natural parasites may be effective in commercial growing environments. Fungus gnats infest home, office, commercial and apartment plants, as well. Insecticide use is not effective. Rather, it is important to constantly monitor your houseplants for winged adults. Do not overwater plants.

Biology, Diet & Habits

Where Do They Live?
These pests are typically found in and around areas with high humidity. Unlike some other flying insects, fully mature fungus gnats often remain low to the ground, close to plants and soil. Adults are seen on leaf litter and foliage, while larvae remain in the soil until they pupate.

While they can live outdoors, fungus gnats are a much greater nuisance when inside. Because soil stays damp longer in controlled, indoor settings, potted houseplants provide the moisture and decaying plant matter that these pests crave. These pests can develop in

  • Fungus that grows in mulch
  • Leaf piles
  • Compost
  • Decomposing plant debris

What Do They Eat?
Fungus gnat larvae feed on damp, organic material in the soil they live in. Some species feed on fungus in overwatered soil, but there are other species that consume plant roots as a source of nutrients.

Larvae begin feeding on fungus or on the root hairs of plants but eventually feed upon the roots of the plant, as well as edible organic material present within the soil. 

Dark-winged fungus gnat larvae feed on roots of:

  • Alfalfa
  • Carnation
  • Clover
  • Corn
  • Cucumbers
  • Easter lilies
  • Geraniums
  • Lettuce
  • Nasturtium
  • Peppers
  • Poinsettias
  • Potatoes
  • Soybeans
  • Wheat

Life Cycle

Eggs hatch within a few days, and fungus gnat larvae emerge. Larvae undergo a pupal stage that spans approximately three days, after which adult gnats emerge. These adult fungus gnats continue the life cycle, increasing the population of their species.

More Information

Fungus Gnat Larvae

Fungus Gnat Life Cycle