"Gnat" is a term that is used interchangeably to describe any number of small flying insects. In this article we will be discussing the "fungus gnat" that commonly invades homes. Fungus gnats in the home are often introduced when infested house plants are brought in or when a water leak goes unnoticed. This type of gnat does not bite and is a nuisance only by its presence. Fungus gnats believe it or not can actually provide a service. By the presence of these small flying pests you can be alerted to a potential moisture issue that you may not have been aware of.
It is important to properly identify exactly what type of insect you are dealing with so that an appropriate pest control program may be chosen. To identify an insect, several adults should be captured and dropped in alcohol. Next your local Cooperative Extension Office should be contacted for information on insect identification in your area.
Identification: What do Fungus Gnats Look Like?
Adult fungus gnats are about 1/8 to 1/10 inch long, fragile grayish to black flies with long, slender legs and thread-like antennae. These gnats have one pair of wings that are clear or smoky-colored with no pattern and few distinct veins. Their eggs are almost invisible to the naked eye, oval, smooth, shiny white and semi-transparent. Fungus gnat larvae are clear to creamy-white with black head capsules and can grow to about 1/4 inch long.
The life cycle of a fungus gnat is about four weeks, with continuous reproduction in homes where warm temperatures are maintained. Generations overlap, with all life stages present during the breeding season. Females lay up to 100 to 300 eggs in batches of 2 to 30 each in decaying organic matter. Eggs hatch in 4 to 6 days. Larvae of the fungus gnat not only feed on decaying matter but also on stems and roots under the soil, causing stunted growth in some plants.
Inspection: Looking for the Source
The first and most important step in getting rid of this pesky pest is finding the source of the gnats. Inspect all your houseplants for a fungus gnat infestation by placing pest monitoring cards above the plant to monitor for adult activity.
For the most part fungus gnats do not cause damage in the home environment. Some greenhouses and plant nurseries may experience damage issues when fungus gnats go unchecked and a large infestation occurs. Larvae of the fungus gnat feed on plant roots and in large numbers can cause significant damage. Since fungus gnats do not bite humans or pets they seem to bother folks by buzzing around their heads and generally just by being there.
Treatment: How to Get Rid of Fungus Gnats
If you have fungus gnats present in your home there are several steps you may take to get rid of them.
- If you find activity in your houseplants, let the soil dry out and this may effectively kill all the larvae, or remove the plant from your home.
- Plants may be treated with Bifen IT to get rid of larvae and adults. Plants should be moved outside prior to treatment and allowed to fully dry before bringing back indoors.
- To get rid of adult fungus gnats flying around your home, use an aerosol product like CB-80 Aerosol or PT Microcare CS Aerosol. Both of these products offer a fast knock down and kill of flying insects.
- Use fly light traps, such as the Flyweb Fly Light, to eliminate adult fungus gnats in your home.
If plants do not seem to be the source of infestation, search for water leaks or damage from water leaks. These areas must be repaired and properly cleaned to stop the breeding cycle and eliminate the population that is infesting your home.
Prevention: Fungus Gnat Control and Management
Preventing fungus gnats from entering your home is quite simple once you know how. Follow these steps to reduce your chance of introducing fungus gnats to your home.
- Inspect all new house plants before bringing into your home.
- Always use sterile potting material. Do not over water plants.
- Inspect any plant that was taken outside and brought back in.
- Discard heavily infested plants.
- Identify and repair any water leaks as soon as possible.