1a larva mines from a case, makes fleck mines => 2

1b larva does not mine from a case => 3

1c galls, etc. => Tables for all parasites per species

2a mouth angle 90°, case perpendicular on the leaf: Coleophora saturatella

2b mouth angle 45°, case obliquely on the leaf: Coleophora trifariella

3a tentiform mine: Phyllonorycter juncei

3b flat, crook-shaped gallery => 4

4a final part of the gallery widened, on top of the midrib: Agromyza johannae and A. pulla

4b gallery hardly widened, never on top (but possibly next to) the midrib: Agromyza luteifrons