1a blotch mine with conspicuous primary and secondary feeding lines: Euleia heraclei

1b no feeding lines visible => 2

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

2a short, shallow corridor, ending upon a thick vein: Napomyza carotae

2b mine different => 3

3a rather broad corridor, mostly following the leaf margin, indistinctly upper-surface; frass in two rows of grains; larva a maggot: Phytomyza chaerophylli

3b small full depth very transparant mine, not associated with leaf margin; larvae with chitinised head and feet => 4

3a mine more or less corrridor-like; often several mines togther in a vein axil; mine contains little frass; larva pale (white-light green) or yellowish=> 5

3b mine more blotch-like, containing more frass; larva green, head black: Agonopterix purpurea

5a larva: head light brown: Epermenia chaerophyllella

5b head black: Epermenia aequidentellus