Origin:
These may be native insects in North America and they are found in southern Canada, nearly all of the U.S., and south into Mexico. They also may be found in Europe.
Biology:
This tiny fly can be a serious pest problem on grasses, including bent grass greens on golf courses, managed turf, and most seriously on crops such as wheat, rye, barley, and corn. The tiny eggs are laid onto various places on the host plant and the larvae burrow into the stems to feed throughout their life. They pupate within the stem or they may emerge to drop to the soil to pupate, and the winter is passed by the larva in the stem at the base of the plant. Several generations occur each year. Infested plants may wilt and die and the presence of the flies may be noted by large numbers of the tiny, black adult flies on the grass in the morning.
Identification:
The adult flies are tiny, only 1/20th inch long, and are shiny black with yellow halteres and often yellow areas on their legs.
Characteristicts Important to Control:
Control is aimed at the adult flies when they are noticed, as the larvae within the stems are protected from most insecticides. An application of a labeled insecticide in very early morning can kill the adult flies that become active on the turf.
