1a corridor, widening into a large blotch => 2

1b a corridor from begin to end => 3

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

2a frass powdery, in black-green clouds along the margins of the blotch or in the end of short side branches: Scaptomyza flava

2b frass in large, widely separated black lumps: Agromyza lathyri

3a puparium in the mine, in a, usually under-surface, pupal chamber: Chromatomyia horticola

3b before pupation the mine is left through a semicircular exit slit => 4

4a frass in a broad, central green band; larva: rear spiraculum with 3 papillae: Liriomyza congesta

4b frass in black thread fragments, never in a green band; rear spiraculum with > 3 papillae => 5

5a corridor pinnately branched, main branch overlying the midrib: Liriomyza strigata

5b corridor not pinnate => 6

6a corridor usually beginning upper-surface, but further on turning lower-surface; most mines in the basal half of the leaf; corridor often follows the midrib for some stretch: Liriomyza huidobrensis

6b corridor beginning lower-surface, often remaining so till the end; mines in the entire leaf, without a tendency to follow the midrib: Liriomyza pisivora