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 very small; larva with thoracic feet; older larvae live free among spun leaves => 3

2b mine normal in size; larva without feet, mines all its life: Orthochaetes setiger

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 lower-surface epidermal mine, < 1 cm, wart-like above: Cystiphora leontodontis

5b mine different => 6

6a upper-surface blotch or broad corridor, with conspicuous feeding lines: Trypeta immaculata

6b no secondary feeding lines => 7

7a upper-surface blotch: Liriomyza taraxaci

7b corridor => 8

8a mine independent from the midrib => 9

8b mine associated with the midrib => 10

9a puparium in the mine, in a, usually lower-surface, pupal chamber; mine not unusually long: Chromatomyia cf. syngenesiae & Ch. farfarella

9b pupation after the larva hes left the mine through a semicircular exit slit; mine starts with an unusually long lower-surface corridor: Phytomyza marginella

10a mine pinnately branched, the main branch overlying the midrib; pupation outside the mine; frass in strings in the corridor; larva: cephalic skeleton with two rearwards directed arms: Liriomyza strigata

10b larva lives in the midrib, makes from there excursions into the leaf; these almost without frass, which is heaped in the base of the hollow midrib; there also the puparium; larva: cephalic skeleton with three rearwards directed arms => 11

11a mandible in the full-grown larva with 1 tooth (check carefully, the mandibles alternate): Ophiomyia pinguis

11b mandible with 2 teeth (of unequal size) => 12

12a larva: front spiraculum spine-like, erect: Ophiomyia pulicaria

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