1a fleck mine: Coleophora lixella

1b corridor or blotch => 2

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

2a larva with feet and chitinised head => 3

2b larva a maggot => 4

3a mine white, strongly inflated: Elachista albifrontella

3b mine pale green, flat: Elachista maculicerusella

4a larva: mandible with 1 tooth; at the start of the mine (often in the leaf sheath!) at the outside an egg shell: Hydrellia griseola

4b mandible with 2 or more teeth; no egg shell => 5

5a larva: cephalic skeleton of Agromyzinae-type; pupation outside the mine ** => 6

5b cephalic skeleton of Phytomyzinae-type; pupation either within or outside the mine => 7

6a larva: behind the mandibles ventrally a spot with spinulose warts; mandible with 2 teeth: Agromyza nigrella / A. mobilis

6b ‘chin’ bare; mandible with 4 teeth (occurrence on this host dubious): Agromyza nigripes

7a mine partly or entirely within the leaf sheath: Cerodontha denticornis

7b mine entirely within the blade => 8

8a puparium in the mine => 9

8b pupation outside the mine => 11

9a puparium partly or entirely orange-brown; front spiracula penetrate the epidermis => 10

9b puparium shining black; front spiracula not penetrating: Cerodontha incisa

10a puparium monochromous; front spiraculum indistinctly bifid: Chromatomyia nigra

10b puparium ventrally with a dark length band; front spiraculum fist-shaped: Chromatomyia fuscula

11a larva whitish; rear spiraculum shaped like a boat hook: Cerodontha calamagrostidis

11b larva yellow, rear spiraculum not unusually shaped => 12

12a larva: rear spiraculum with 3 papillae: Liriomyza flaveola

12b rear spiraculum with ≥ 8 papillae => 13

13a mine in the leaf blade: Cerodontha flavocingulata

13b mine in the leaf sheath: Metopomyza flavonotata