1a mine, when held against the light, with lighter and darker patches; larva a maggot: Scaptomyza flava

1b mine regularly full depth; larva with sclerotised head => 2

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

2a mine a more or less branching corridor; larva without feet: Ceutorhynchus minutus

2b mine blotchy in the end; larva with thoracic feet: Phyllotreta nemorum