Pegomya hessei (Séguy, 1923)
Large, very transparant blotch, with primary and secundary feeding lines. The black frass is concentrated in the oldest part of the mine, near the leaf margin. Mines can coalesce, and then contain several larvae. At the start of the mine, at the leaf underside, a white egg shell. Howvever, the larva can leave its mine and restart elsewehere, therefore mines without an egg shell may occur as well.
Larvae in October.
distribution within Europe
Carduophila fodiens Hendel, 1925.
Hartig (1939a), Hering (1957a).