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

1b mine upper- or lower-surface; larva a maggot => 5

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

2a mine large; larva, pale and without feet, mines all its life: Orthochaetes setiger

2b mine small; larva, dark and with thoracic legs, mines only briefly, lives later free among spun leaves => 3

3a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

3b pinacula black => 4

4a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

4b anal comb absent: Cnephasia stephensiana

5a upper-surface blotch or wide corridor, with conspicuous secondary feeding lines => 6

5b no secondary feeding lines apparent => 7

6a mine not associated with the midrib, brown: Liriomyza endiviae

6b mine positioned over the midrib, greenish: Trypeta immaculata

7a mine associated with the midrib => 8

7b mine independent of the midrib => 13

8a larva in the midrib, which is galled and swollen (actually a gall rather than a mine) => 9

8b midrib not galled and swollen => 10

9a on Crepis biennis: Phytomyza robustella

9b on Crepis paludosa: Phytomyza araciocecis

10a mine pinnately branched; main corridor overlying the midrbib; frass apparent, in strings; pupation after the mine has been vacated; larva: cephalic skeleton of the Phytomyzinae-type: Liriomyza strigata

10b larva lives within the hollow midrib, makes from there excursions into the lamina; these branches are almost free of frass; frass is concentrated in the base of the hollow midrib; there also the pupation; larva: cephalic skeleton of the Agromyzinae-type => 11

11a larva: rear spiraculum with 8-9 papillae: Ophiomyia cunctata

11b arva: rear spiraculum with > 10 papillae => 12

12a larva: front spiraculum spinelike, pointing upward: Ophiomyia pulicaria

12b larva: front spiraculum broad, curved: Ophiomyia beckeri

13a puparium in the mine in a, usually lower-surface, pupal chamber; corridor not unusually long: Chromatomyia cf. syngenesiae

13b pupation after the mine has been vacated; mine starts with an unusually long lower-surface corridor: Phytomyza marginella