1a mine upper- and/or lower-surface; larva a maggot: Scaptomyza flava

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

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

2a more or less a corridor, starting at the midrib, withour frass: Ceutorhynchus pallidactylus

2b the mine does not start at the midrib => 3

3a mine small, with little or no frass; older larvae live free => 4

3b mine > 1 cm, containing clear amouns of frass; larvae mine life long => 6

4a larvae light in colour: Plutella xylostella

4b larvae dark grey or dark green => 5

5a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

5b pinacula black: Cnephasia asseclana

6a frass in thread fragments; mine an untidy corridor; larva without thoracic feet: Ceutorhynchus minutus

6b frass in lumps; mine an irregular blotch; larva with thoracic feet: Phyllotreta nemorum