1a mine < 1 cm, full depth, often in numbers together in a leaf axil; larvae, with distinct feet and chitinised head, later live free and cause extensive window feeding => 2

1b ine > 1 cm, not full depth; larva a maggot => 3

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

2a high mountain species: Epermenia aequidentellus

2b lowland species: Epermenia chaerophyllella

3a inter-parenchymatous blotch, yellow-green, later brown, perforate, resembling fungus damage (occurence on this host needs confirmation) : Phytomyza heracleana

3b mine not inter-parenchymatous or perforate, upper- or lower-surface => 4

4a blotch with conspicuous primary and secondary feeding lines; larva: rear spiracula with 3 papillae: Euleia heraclei

4b mine rather a corridor, without feeding lines; rear spiracula with 6 or more papillae => 5

5a puparium in the mine in a, usually lower-surface, pupal chamber: Chromatomyia horticola

5b larva leaves the mine prior to pupation => 6

6a corridor very shallow, greenish; frass in initial part of the mine in pearl chains; larva: mandible with 1 tooth: Phytomyza seseleos

6b corridor deeper, whitish; frass in initial part in grains; mandible with 2 teeth => 7

7a mine with some small elongate full depth patches: Phytomyza mylini

7b mine nowhere full depth: Phytomyza libanotidis