a genus of insects of the family Anthomyiidae. The Phorbia are small flies (body length to 6 mm) with black wings. They are pests of cereal crops, mainly spring wheat. The eggs are laid in the leaf sheaths. The larvae develop in the stalks, in which they make spiral passages and eat away the succulent tissues. The damaged stalks usually stop growing, and the leaves on them turn yellow. The flies hibernate in false cocoons in the soil.
Control measures include deep fall plowing and early spring sowing of less susceptible hard varieties of wheat.