1a mine centered over the midrib => 2

1b a corridor, not associated with the midrib => 4

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

2a pinnately branched corridor, main branch overlying the midrib: Liriomyza strigata

2b blotch, may have short lateral extensions => 3

3a blotch irregular in shape, with some full depth patches; larva slender, rear spiraculum ending in an acute point: Scaptomyza graminum

3b elongated blotch, entirely upper-surface; larva more squat, rear spiraculum with 3 papillae: Liriomyza xanthocera

4a long corridor; larva a maggot => 5

4b mine different; larva with chitinised head => 6

5 a puparium in the mine in a, usually lower-surface, pupal chamber; frass in well-spaced grains: Chromatomyia horticola

5b pupation outside the mine; frass in thread fragments: Liriomyza bryoniae

6a mine contracts, because silk is deposited within: Cnephasia lineata

6b mine flat, without silk: Antigastra catalaunalis