1a blotch mine, may be preceded by a corridor => 2

1b corridor mine => 6

1c fleck mine => 12

1d smalll, full depth mines of indefinite shape => 14

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

2a secondary feeding lines conspicuous => 3

2b no secondary feeding lines visible => 5

3a yellow-green or brown blotch that occupies the entire distal part of a leaf segment: Stemonocera cornuta

3b narrow brown blotch (or corridor), positioned over the midrib => 4

4a mine with a dark centre: Trypeta artemisiae

4b no dark centre: Trypeta zoe

5a mine under or upper-surface, opaque; larva a head- and footless maggot; common species : Calycomyza artemisiae

5b mine full deep, transparant; larva with distinct head and feet; rare species: Digitivalva pulicariae

6a corridor pinnately branched, main branch positioned over the midrib => 7

6b corridor not pinnately branched, not associated with the midrib => 8

7a mine brown, with secondary feeding lines; side branches are short lobes; mine without a narrow lower-surface corridor: Trypeta zoe

7b mine greenish white, without secondary feeding lines; side branches longer and more slender; mine begins with a long and narrow lower-surface corridor: Liriomyza strigata

8a puparium in the mine => 9

8b larva leaves the mine prior to pupation; vacated mines have a semicircular exit slit in the epidermis => 10

9a mine a long corridor, upper or lower side, not strongly wound; frass in discrete grains: Chromatomyia cf. syngenesiae

9b mine shorter and more strongly wound, usually in the tip of a leaf segment; frass in pearl chains: Liriomyza eupatoriana

10a first part of the corridor in a dense spiral; the leaf tissue there dies and turns brown (if the mine starts close to thje leaf margin the spiral may be incompplete or missing); the spiral continues in a long upper-surface corridor: Liriomyza eupatorii

10b no initial spiral; corridor upper- or lower-surface => 11

11a larva rear spiraculum with ≥ 20 papillen; European species: Phytomyza eupatorii

11b rear spiraculum with 3 papillae; introduced tropical species, in northern Europe mainly in greehouses: Liriomyza trifolii

12a larva in a spatulate leaf case: Coleophora conyzae

12b larva in a tubular silken case => 13

13a case 9-10 mm: Coleophora follicularis

13b case c. 15 mm: Coleophora inulae

14a larvae without thoracic feet; they mine all their life: Phytosciara macrotricha

14b larvae with thoracic feet; older larvae live free among spun leaves => 15

15alarva: pinacula colourless (the bases of the setae themselves are black): Cnephasia incertana

15b pinacula black: Cnephasia asseclana