1a larva with distinct, chitinised head capsule => 2

1b larva a maggot => 6

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

2a larva without thoracic feet: Pseudophytobius acalloides

2b thoracic feet present => 3

3a darkly coloured, greyish green: Cnephasia incertana

3b (largely) light coloured => 4

4a head black: Caryocolum vicinella

4b head light brown => 5

5a with a red length line: Scrobipalpa salinella

5b no red length line: Scrobipalpa spergulariella

6a frass powdery, in green clouds (often visible only after opening the mine); larva: rear spiraculum (apparently) ending in only one papilla: Scaptomyza graminum

6b frass different; posterior spiraculum with three or more papillae => 7

7a anterior spiraculum with two papillae: Clanoneurum cimiciforme

7b anterior spiraculum with three or more papillae => 8

8a larva: mandibles with two teeth => 9

8b mandibles with three or more teeth => 10

9a larva: posterior spiraculum with 10-16 papillae: Liriomyza strigata

9b posterior spiraculum with 5-9 papillae: Liriomyza bryoniae

10a the larve mines the upper leaves, migrating from one leaf to the other by way of the stem; this causes wilting of the tip of the shoot: Delia echinata

10b the larva primarily is a stem borer, only occasionally making an excursion into a leaf; the shoot tip does not wilt: Delia florilega