1a the mine radiates from a galled portion of the midrib of petiole: Ceutorhynchus chalibaeus

1b no association with a gall => 2

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

2a larva a maggot; mine (partly) lower-surface of upper-surface => 3

2b larva with chitinised head; mine full depth => 6

3a gallery from start to end => 4

3b mine finally a blotch => 5

4a corridor pinnately branched; pupation external: Liriomyza strigata

4b corridor not pinnate; pupation within the mine, in a, generally lower-surface, pupal chamber: Chromatomyia horticola

5a frass in black strings: Liriomyza xanthocera

5b frass grains powdery, in green clouds, often visible only after opening the mine: Scaptomyza flava

6a mine small, roundish, often several in a leaf; larvae with prolegs; they mine only briefly, then live free under the leaf: Plutella xylostella

6b mine more or less a corridor; larvae without prolegs; they mine till just before pupation => 7

7a larvae with thoracic legs: Phyllotreta nemorum

7b larvae without legs => 8

8a mine radiates from the leaf base, sometimes the midrib: Orthochaetes insignis

8b mine not associated with leaf base or midrib, often near the leaf margin: Ceutorhynchus minutus