1a lower-surface tentiform mine: Phyllonorycter cephalariae

1b (usually, largely) upper-surface corridor => 2

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

2a corridor pinnately branched, main axis on top of the midrib; pupation external: Liriomyza strigata

2b corridor irregularly branched, without association with the midrib; pupation within the mine, in a, generally lower-surface, pupal chamber: Chromatomyia horticola