Jeff Hahn, University of Minnesota
Photo 1: Look for red eyes when identifying fruit flies, although the color dulls after they die.
Most fruit flies have red eyes which help to identify them. They also have a brownish body and a dark colored abdomen. There are other small-sized flies, such as fungus gnats, moth flies, and humpbacked flies, that can be confused with fruit flies. The control varies with the type of fly that is found so it is very important to correctly the insect you are seeing.
The best control of fruit flies is to find the source of the infestation and remove it. This often takes detective work to locate the problem as many times it is not obvious. It is tempting to just spray or kill the adults that are seen. However, as long as a food sources remains, it is very difficult, if not impossible, to get ahead of the problem and eliminate all of the flies.
For more information, see Fruit Flies.