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Fungus Gnats


Fungus Gnats are insects measuring about 1/16 inch in length. They are grayish-yellow to dark brown in color. Fungus Gnats thrive in moist conditions. While they feed on fungi and decaying matter, they have seldom been known to cause damage to African Violets. Generally speaking, they are more of a nuisance than a danger.

Distinguishing Symptoms

Fungus Gnats are tiny insects, grayish-yellow to dark brown in color. They swarm around your Violet when the leaves are disturbed. Their appearance and behavior is similar to that of Blackflies, Mushroom Flies and Sciarid Flies. If you have narrowed down your diagnosis to any of these insects, do not concern yourself with making a definitive identification. The treatment is the same for all four insects. (See below.)


To treat for Fungus Gnats, use a household insect spray containing Acephate. Start by gently tapping the leaves of your Violet. As the gnats swarm up, you can direct the spray away from your Violet. Next, gently spray a light mist over your Violets and into the soil in order to get any gnats that remain. This will also get the young larvae. Apply as directed on the label and be careful not to spray too much. Too much Acephate may cause damage to the leaves. (Note: Many household insect sprays, which contain Acephate, also contain a specific additive that may damage the foliage of African Violets. Therefore, if available, use a soluble powder, and mix your own spray.)

As an alternative to traditional chemical treatments, you want want to try trapping the insects. This can be done by taking a narrow strip of wood, painting it with a bright color and coating it with something sticky. Your wood should be about 12 to 18 inches long and 1 to 3 inches wide. Paint it orange or deep yellow, then apply a generous coating of honey or molasses. According to those who use this method, the bright color attracts the insects. Once they land on the strip, the honey or molasses holds them there. To be effective, the strip must be placed among your Violets so that it is in close proximity to wherever the insects are flying.


As Fungus Gnats thrive on fungi and decaying matter, the best prevention is to simply keep your Violet clean of dead and dying tissue, including leaf and flower debris which may have dropped onto the soil.

Important Note on the Use of Pesticides

Please note that almost all pesticides are formulated for specific uses and conditions. When applied incorrectly, pesticides can cause ill health or damage to plants. Therefore, when using any kind of pesticide or chemical treatment, always apply as indicated on the product label.

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