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

1b mine (mostly) entirely upper- or lower-surface; larva a maggot => 4

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

2a mine < 1 cm; larva later lives free, causing window feeding: Plutella xylostella

2b mine larger; larva remains in the mine till shortly before pupation => 3

3a larva without feet; corridor sides rather smooth: Ceutorhynchus minutus

3b larva with thoracic feet; corridor sides irregularly indented: Phyllotreta nemorum

4a blotch with lobelike extensions; frass powdery, in green clouds: Scaptomyza flava

4b corridor; frass black, grains or strings => 5

5a corridor unbranched; puparium in the mine, in a, usually lower-surface, pupal chamber; frass in widely dispersed grains: Chromatomyia horticola

5b corridor pinnately branched, main branch overlying the midrib; pupation outside the mine; frass in strings or pearl chains => 6

6a main branch slender, definitely a corridor: Liriomyza strigata

6b main branch wider, rather an elongated blotch: Liriomyza xanthocera