How to ID Fruit Flies, Drain Flies and Fungus Gnats

How to ID Fruit Flies, Drain Flies and Fungus Gnats

Drains can build up sludge that attracts fruit flies and drain flies. TERRO® has solutions for dealing with both of these pests.

When your home is under siege by tiny little flying insects, it can be easy to assume that you’re battling fruit flies, but that may not always be the case. Your problem may indeed be fruit flies, but two other insect species, the drain fly and the fungus gnat, should also be on your hit list.

Dealing with each of these species requires different tactics, so your first goal should be to identify the invader.

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How to ID Fruit Flies

Without a doubt, fruit flies are the most common flying insects that will pester you in the kitchen. They are attracted to fresh and decomposing fruit as well as sugary juices and alcohol.

  • Colors: The two most common fruit flies, the Red Eyed Fruit Fly and the Dark-Eyed Fruit Fly, have striped abdomens. Their eye colors are, as the name suggests, red or black, respectively.
  • Size: Red Eyed Fruit Flies are about ⅛-inch long. Dark Eyed Fruit Flies are a bit bigger, at about 316-inch long.
  • Body type: Similar to a house fly, but much smaller.
  • Where: Fruit flies may be buzzing around your fruit bowl, inside a trash receptacle, in a recycling bin or in your drain or garbage disposal.

How to ID Fungus Gnats

If you spot a swarm of bugs flitting above a houseplant, you probably have fungus gnats instead of fruit flies. Fungus gnat larva and pupa prefer moist soil to protect them as they develop. Before they progress to adult form, they can severely damage the root system of your potted plants.

  • Colors: Adults - brown or black with light colored legs.
  • Size: Adults are less than ⅛-inch long. Their larva and pupa forms are about the same size.
  • Body type: Although they are technically flies, they have a mosquito-like appearance.
  • Where: Fungus gnats will be spotted flying close to your potted plants and will show little interest in going anywhere else as long as there is moist soil available.

How to ID Drain Flies

These hairy bugs are another kitchen pest. They thrive in dark, damp conditions and often find an ideal home inside a drain, which can include a floor or a sink drain, sink overflow or another area open to plumbing. Although they don’t bite, their presence can aggravate asthma in some people.

  • Colors: Light gray or tan with a dark border around wings.
  • Size: About ⅛-inch long.
  • Body type: Moth-like with fuzzy bodies and antennae.
  • Where: Drain flies breed inside of drains, often laying eggs in the sludge that accumulates inside. Adults will clumsily fly out of the drain and land nearby on walls and ceilings.

Fruit Fly Prevention & Eradication Tips

The best way to get rid of fruit flies is to keep your kitchen and garbage receptacles clean of any accumulated debris that may attract them. This includes thoroughly rinsing out beverage containers, using fruit quickly or placing it in the refrigerator, sealing garbage cans and removing refuse regularly from the area.

As you continue to work on preventing fruit flies, place TERRO® Fruit Fly Traps around the area to attract and trap any lingering adult fruit flies. Even better, these attractive traps have a decorative look which allows them to sit on countertops, windowsills and kitchen islands without attracting the attention of your human guests.

If your fruit fly problem persists, the issue may lie in your drain. Sludge and other organic material that attracts these pests can build up and provide an egg-laying area for these bugs, even if you repeatedly try to flush out the system. To clean this problem area, run a drain cleaner through your plumbing.

Fungus Gnat Prevention & Eradication Tips

Preventing fungus gnats should begin when you first purchase a houseplant. Before bringing it into the home, pull it out of the pot and look for signs of these pests, including glossy, clear larvae. Obviously, any plant that already has gnats flying around it should be left at the store.

The other simple prevention method is to ensure that your plants aren’t overwatered. Fungus gnats prefer moist material to deposit their eggs. Further, avoid adding water-retaining material when potting a plant such as peat moss.

If you have fungus gnats, add Safer® Brand Houseplant Sticky Stakes to your pots. These stakes contain simple yellow-colored glue traps that attract adult fungus gnats. By attracting and killing off the adults, you will eventually eliminate most of the remaining gnats as they reach the adult stage. Additional control efforts should include allowing your plant soil to dry out and applying “beneficial nematodes.” These are tiny worms that seek out and eat the larvae of fungus gnats without damaging your plant or becoming pests themselves.

Drain Fly Prevention & Eradication Tips

Eliminating drain flies requires a few steps. Once you recognize that you have drain flies, put some tape over the drains where you suspect they are emerging and leave it overnight. The next day, check to see if any flies have been collected.  Once you know their source, you can begin eradication:

  • Clean the drain. Pour 2 to 4 quarts of warm water down the drain to moisten any material stuck inside. Then use a metal pipe brush or plumbing snake to break up and pull out any grime or sludge.
  • Add drain cleaner. Pour a gel down the drain and follow its instructions for use.
  • Flush the system. A few hours after applying the drain cleaner, flush more warm water down the pipe to eliminate any remaining sludge.
  • Kill any remaining adults outside the drain. Smack them with a fly swatter or spray them with an insecticidal spray and then clean the area thoroughly.

To keep drain flies from returning, keep drains clean and eliminate stagnant water (including water in potted plant saucers) in the home.

Your Solutions

Do you have your own solutions for dealing with fruit flies, drain flies or fungus gnats? Let us know in the comments below or visit us on Facebook with your DIY insect eradication tips.

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