Turnip sawfly (Athalia colibri)

The Turnip Sawfly (Athalia colibri) lays its eggs on the cotyledons and first true leaves after rapeseed emergence. After hatching, the young larvae gnaw the lower epidermis in the form of small pits. As they grow, they chew holes in the leaves, which gradually enlarge, or make peripheral gnawings. In case of a mass infestation, they cause complete defoliation by gnawing the central vein, leaf petioles, and the growing tip.