Chlorops pumilionis is a species of pest fly from the family Chloropidae. It is also known as the chloropid gout fly or barley gout fly. It is an oligophagous pest of cereal crops.
The thorax is straw yellow, with three longitudinal nodal stripes. The head has black ocular triangle. The third antennal segment and two last segments of tarsus are black.
The fly is widespread in South, North, Central Europe, North America, Africa, and Japan.
The gout fly damages 18 species of cultivated and wild cereal plants, wheat, barley, rye, oats, timothy grass and couch grass.