Gnats are small, winged insects that thrive in moist environments, but they can also be difficult to kill. Measuring only 1/10 to 1/8 inch long, the gnat is a nuisance to humans and can adversely affect the roots of certain plants. Knowing how to control and exterminate these creatures is essential if you have an infestation. Fruit flies, fungus gnats and vinegar flies are all termed gnats, though each is a separate, but related, species.
Female gnats lay their eggs in moist areas and can produce thousands of eggs. The eggs hatch and develop into larvae in a matter of days. Larvae feed for about 12 to 14 days and become pupae. The pupae can reach maturity in five to six days. Gnats become adults and live for another seven to 10 days before expiring.
In order to control the gnat population, you must root out its source. Find areas where there is too much moisture. Potted plants with overly wet soil, outdoor gardens with standing water, rotting framework, crawlspaces and leaky outdoor faucets are the usual breeding grounds. If the gnats are indoors, take potted plants outdoors where they can dry out. Fumigate crawlspaces with insect foggers and replace rotting boards.
If the gnats are outdoors, use pesticides such as Vectobac or Gnatrol. Another way to combat outdoor gnats is through the use of insect parasitic nematodes. Nematodes feed upon the gnats and are effective in destroying the gnat community.
Prevention and Maintenance
The best way to combat gnats is keep them from materializing. Fruit flies love mushy, molding produce. Get rid of old fruits and vegetables that are spoiling and securely wrap them in plastic before discarding. Throw out your trash on a regular basis and be sure to cover receptacles tightly.
Keep the plumbing in proper working condition by repairing leaks immediately. Also, don't water indoor plants too much. Allow the soil to dry out before you water again.