Recently hatched larvae are pale grey to greenish in colour, older larvae change colour to become dark green to black on the back and grey on the ventral surface. The head capsule is shiny black. Egg laying commences a few days later. After feeding, the females laterally incise the leaves in a sawtooth pattern and deposit their eggs one by one in the small chambers, constructed for preference on yellow leaves. Fecundity of the females is approximately 300 eggs.
Unfertilized eggs produce male larvae.
After moulting, the exuviae remain on the leaf. Pupation occurs after 10 to 13 days in the upper layers of the ground at a depth of 1 to 5 cm, inside a cocoon. The final larval stage hibernates underground in a cocoon. In July-August, the second sawfly generation appears and lays its eggs on plants grown as green manure and fodder crops. Under favourable weather conditions, a third generation occurs, causing damage to winter rape .