1a mine full depth; larva with chitinised head => 2

1b mine upper- or lower-surface; larva a maggot => 3

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

2a mine tiny; larva with thoracic feet; older larvae live free among spun leaves: Cnephasia stephensiana

2b mine large; larva without feet, mines all its life: Orthochaetes setiger

3a min in and/or on top of the midrib, with short branches, without frass: Ophiomyia pulicaria

3b mine winds freely through the leaf, independent of the midrib; frass obvious, in isolated grains: Chromatomyia cf. syngenesiae