Root Aphids vs. Fungus Gnats: Most Common Differences

Root aphids and fungus gnats could be easily mistaken for one another unless they are looked at closely. Both pests are a nuisance to gardeners and they should be treated quickly to prevent the infestation from growing. Learn how to distinguish these two pests before you try to get rid of them as they may require different methods of elimination.

Appearance of Gnats and Aphids
The easiest way to distinguish these insects is by body color. Root aphids, in general, have a bright body color (yellow or white), while fungus gnats are generally dark brown or black.

The fungus gnat larvae do have a white body color but they should be easily distinguishable from aphids due to their long, slender body.

Behaviors of Gnats and Aphids

There is also a big difference in the behaviors between root aphids and fungus gnats. The latter can fly when they become adults while aphids stay rooted to the ground or the plant surface. Winged aphids do exist but they are more often referred to as greenfly or blackfly.

Control and Prevention
It’s important to get rid of fungus gnats and root aphids as soon as they are identified. Root aphids, in particular, can stunt a plant’s growth by sucking out the sap from the plant roots. Common symptoms of aphid-infested plants include the discoloration of leaves and the stunted growth of the plant stem.

Fungus gnats, don’t really harm plants but they are often an indication of improper plant care (e.g. over-watering of soil, lack of sunlight).