1a small upper-surface reddish wart (< 1 cm), an epidermal blotch below: Cystiphora sanguinea

1b fleck mine => 2

1c mine full depth; larva with chitinised head => 5

1d mine upper- or lower-surface; larva a maggot => 8

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

2a larva mines from a silken tube attached to the plant => 3

2b larva mines from a portable case => 4

3a pupation within the mine: Vulcaniella pomposella

3b pupation external: Scythris siccella

4a mouth angle 45-60°; case slender: Coleophora trochilella

4b mouth angle 20°; case somewhat paunchy: Coleophora ramosella

5a larva yellowish brown, without feet, mines all its life: Orthochaetes setiger

5b larva (dark) grey, with thoracic feet and prolegs; older larvae live free among spun leaves => 6

6a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

6b pinacula black => 7

7a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

7b anal comb absent: Cnephasia stephensiana

8a secondary feeding lines conspicuous; mine centered above the midrib: Trypeta immaculata

8b no secondary feeding lines => 9

9a mine independent of the midrib => 10

9b mine on or (partly) in the midrib, or seemingly ending upon the midrib => 14

10a (elongated) primary blotch: Liriomyza hieracii & L. hieracivora

10b corridor => 11

11a frass in discrete grains => 12

11b frass in pearl chains or strings => 13

12a puparium in the mine in a, usually lower-surface, pupal chamber; mine not exceptionally long: Chromatomyia cf. syngenesiae

12b pupation outside the mine; mine starts with an unusually long lower-surface corridor: Phytomyza marginella

13a puparium in the mine (in midrib or petiole): Phytomyza rufescens

13b larva leaves the mine before pupation through a semicircular exit slit: Phytomyza erigerophila

14a corridors with frass in strings; larva: cephalic skeleton with two rearwards pointing arms => 15

14b corridors almost without frass; cephalic skeleton with three rearwards pointing arms => 16

15a side branches of the mine slender, parallel sided, relatively long; pupation outside the mine; larva: rear spiraculum with 10-17 papillae: Liriomyza strigata

15b side branches irregular, rather short; pupation in midrib or petiole; rear spiraculum with > 20 papillae: Phytomyza rufescens

16a corridor ends upon the midrib; from there the larva descends along the stem as a cortex miner; puparium in the stem, close to the root collar: Ophiomyia curvipalpis

16b larva lives within the hollow midrib, makes from there excursions into the lamina; frass is concentrated in the base of the hollow midrib; there also the pupation: Ophiomyia pulicaria