1a fleck mine => 2

1b corridor or blotch => 3

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

2a larva in a helicoidal case; hole, in the mine angular: Apterona helicoidella

2b larva free; hole in the mine untidily torn out: Aricia agestis

3a blotch; at the ovipostion site (usually on the midrib, upper-surface) a brownish-black drop of dried secretion: Habroloma geranii

3b no such drop => 4

4a mine upper- and/or lower-surface; larva a maggot => 5

4b mine full depth; larva with chitinised head => 6

5a pinnately branched gallery, branches on top of the larger leaf veins; feeding lines hardly or not al all apparent: Liriomyza strigata

5b mine an irregular gallery, not associated with the venation of the leaf; primary and secondary feeding lines conspicuous: Agromyza nigrescens

5c mine not as one of these: unknown agromyzid

6a gallery, starting from a semiglobular, shining egg shell: Stigmella aurella

6b no egg shell visible at start of the gallery => 7

7a larva without feet: Orthochaetes insignis

7blarva with thoracic feet => 8

8a larva bone coloured, with a black spot ventrally on the thorax segments (the larva lies belly-up in the mine); the larve mines all its life => 9

8b larva grey; older larvae live free among spun leaves => 10

9a imago: antenna with 12-14 segments; species of the plains, living on various Geranium-species: Fenella minuta

9b imago: antenna with 14-16 segments; boreo-alpine species, with certaintly known only from G. sylvaticum: Fenella monilicornis

10a mine small => 11

10b mine not unusually small => 12

11a larva: pinacula colourless (the bases of the setae themselves are black): Cnephasia incertana

11b pinacula black: Cnephasia stephensiana

12a mine almost flat; species of Central and South Europe: Cnephasia ecullyana

12b mine strongly inflated because much silk was deposited inside; species of southeastern Europe: Cnephasia lineata