1a mine small, of indefinite shape, full depth; larva with thoracic feet and a recognisable head; older larvae live free among spun leaves => 2

1b mine not unusually small, upper- or lower-surface, a clear corridor; larva, a maggot, mines all its life => 4

1c gallen etc => Tabellen voor alle parasieten per soort

2a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

2b pinacula black => 3

3a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

3b anal comb absent: Cnephasia stephensiana

4a pupation within the mine, in a, generally lower-surface, pupal chamber: Chromatomyia syngenesiae

4b pupation external => 5

5a corridor pinnately branched, entirely or largely upper-surface: Liriomyza strigata

5b corridor not pinnate; a large section of the corridor is lower-surface, only the last part upper-surface: Phytomyza marginella