This insect feeds on several cereal species, the most frequently affected being wheat , barley , rye and, in places, oats . After reaching their full size in June or May, larvae penetrate the soil to a depth of 6-10 cm and enter a state of diapause . Following wet springs, this insect is particulary numerous.
Internodes remain short and damaged parts can be broken easily.
Affected ears mostly remain in the sheaths and produce atrophied grains. Severe damage caused to plants at the edge of fields is typical of this insect. The sheath has burst and the stem is distorted. . On the right, a part of the sheath has been removed to show the larvae.