Fungus gnats (Bradysia spp.) are small flies that look like miniature mosquitoes darting around near the surface of the soil or potting medium. The larvae feed on fungi and decaying plant material in the potting medium; they are worm-like, about 1/4 inch long with a distinctive shiny black head. Heavy populations of fungus gnat larvae can also feed on plant roots and be quite devastating on rooted cuttings. The result is stunted plants that do not grow as fast as pest-free plants. Tender young plants, especially slow growing seedlings, are destroyed by larval feeding. It is known that fungus gnats actively transmit fungal spores from diseased plants to healthy plants.

Cultural control options include maintaining a dry, level, weed-free, well-drained area around your crop to help eliminate breeding areas. Since fungus gnats require moist soil or substrate for development, overwatering plants should be avoided. Potting media should be stored dry, and pots and production areas must be well drained. Fungus gnats can exist on soil fungi, algae under benches and on damp mossy benches. Fungus gnat populations can be detected and monitored with the use of yellow sticky cards. In addition to good cultural practices, treatment measures may be required for control of fungus gnats with products such as Citation^® insect growth regulator and Flagship^® 25WG insecticide.

Citation^© insect growth regulator (IGR) effectively controls fungus gnats, shore flies and Dipterous leafminers in production ornamentals. For control of fungus gnats and shore flies larvae, apply 2.66 oz. of Citation in 100 gallons of water as a drench to all surfaces where insect pests may breed. Generations of fungus gnats overlap so control with an IGR may be slow under heavy pressure.

Flagship^© 25WG insecticide provides foliar and systemic control of insect pests on ornamental plants grown in greenhouses. Flagship 25WG is a broad-spectrum insecticide that is active against many sucking and chewing insect pests by contact and ingestion. When applied as a drench, Flagship delivers very effective control of fungus gnat larvae.

©2014 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your local extension service to ensure registration status. Citation^® and Flagship^® are trademarks of a Syngenta Group Company.