1a blotch, no trace of a preceding corridor => 2

1b corridor, may widen into a blotch => 6

1c fleck mine; larva in a lobe case => 15

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

3a mine tiny; larva yolk-yellow: Spialia sertorius

3b mine larger; larva not yellow => 4

4a on the oviposition spot, usually near the leaf margin, a shining black drop of dried secretion: Trachys fragariae

4b no such drop => 5

5a larva: no claw at the end of the feet; common species: Fenella nigrita

5b the feet end in a distinct claw; only known from Hungary on P. cinerea: Fenella arenariae

6a mine begins at a globular, shining egg shell => 7

6b no egg shell visible => 13

7a mine begins with a strongly contorted corridor: Ectoedemia arcuatella

7b initial corridor not contorted => 8

8a mine remains a gallery till the end => 9

8b gallery widens into an irregular, often large, blotch => 11

9a egg at the underside of the leaf: Stigmella thuringiaca

9b egg at the upperside (rarely underside, but the gallery then very slender) => 10

10a frass in the first section of the gallery diffuse, greyish green: Stigmella anomalella

10b frass black and granular, also in the first section: Stigmella splendidissimella

11a egg at the upperside: Stigmella poterii

11b egg at the underside => 12

12a lowland species: Stigmella aeneofasciella

12b always, or almost always, high in the mountains: Stigmella stelviana (always) & Stigmella tormentillella (almost always)

13a initial corridor short, quickly widening; mine full depth; larva with chitinised head => 5

13b initial corridor longer and/or widening more slowly; mine upper- or lower-surface; larva a maggot => 14

14a frass in the corridor part in two rows of grains; larva: rear spiraculum with 3 papillae: Agromyza idaeiana

14b initial corridor almost full of frass; rear spiraculum with 6 papillae: Agromyza sulfuriceps

15a case helicoidal; opening of the mine not neatly circular: Apterona helicoidella

15b case more or less straight; opening a perfect circle => 16

16a spatulate leaf case: Coleophora albicostella

16b lobe case => 17

17a case brown; lobes of the case cut out of the upper epidermis; mouth angle 0°-10°: Coleophora violacea

17b case whitish; lobes cut out of the lower epidermis; mouth angle 20°-30°: Coleophora potentillae