Fungus gnats and fruit flies are two of the most common, and annoying, insects found in homes. Both are in the insect order Diptera and adults are about ⅛ inch long. Even though they’re small, there are several physical characteristics you can use to identify them. They also cause different types of damage and tend to hang out in different places.
Whether you notice them on your houseplants or buzzing around your kitchen, you’ll need to know which pest you’re dealing with to get rid of them. Keep reading to learn everything you need to know to eliminate these pests fast.
Fungus Gnats Vs Fruit Flies
How To Identify Fungus Gnats Vs Fruit Flies
While both fungus gnats and fruit flies are similar in size, there are many physical and behavioral characteristics you can use to identify them. The table below will help you quickly determine which pest is in your home.
| Characteristic | Fungus gnats | Fruit flies |
| Overall Appearance | Light brown to black; body form stout; legs and antennae short | Black to gray; body slender, tapering towards backend; legs and antennae longer |
| Eyes | Small, black eyes | Large, red eyes |
| Food | Decaying organic matter in soil, fine roots | Fermenting foods, especially fruits and vegetables |
| Habitat | Near moist soil in house plants. Adults may also be attracted to light near bright televisions or windows. | On fruits and vegetables, near kitchen sinks or trash cans where decaying food can be found |
Damage Caused By Fruit Flies Vs Fungus Gnats
In large numbers, the feeding damage fungus gnat larvae cause to plant roots can cause their leaves to droop and turn yellow [1]. They can also transmit several fungal pathogens to plants.
On the other hand, fruit flies are mainly a nuisance since they will only feed on overripe or decaying foods.
How To Get Rid Of Fungus Gnats Vs Fruit Flies
The best way to get rid of fungus gnats is to keep the top two inches of soil in potted plants dry. This stops the larval stage from being completed, ending the reproduction cycle. You can reduce topsoil moisture by bottom watering your plants. Place a saucer underneath the pot, fill it with water, and the soil will pull the water up into the root zone.
Alternatively, you can add 1 inch of sand over the soil in your potted plants. The sand will dry out quickly, preventing fungus gnat larvae from completing their development. You can also trap adults by placing yellow sticky traps near houseplants.
The best way to get rid of fruit flies is to eliminate their food source. Put fruits and vegetables in the fridge and add a lid to trash cans. Also, make sure to keep sink food traps and garbage disposals clean. If all food sources are gone, fruit flies will stop reproducing.
To trap adults, you can fill a container with apple cider vinegar and a few drops of soap. The fruit flies will be attracted to the vinegar and drown when they try to land.
References
[1] Cloyd, R. A. (2008). Management of fungus gnats (Bradysia spp.) in greenhouses and nurseries. Floriculture and Ornamental Biotechnology, 2(2), 84-89.