1a a corridor, of roughly equal width throughout its length => 2

1b mine (partly) an elongated blotch => 4

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

2a frass in loose, widely dispsersed grains; puparium in the mine, in a, usually lower-surface, pupal chamber: Chromatomya horticola

2b frass in strings or thread fragments; pupation outside the mine => 3

3a corridor unbranched, not associated with the midrib: Liriomyza bryoniae

3b corridor usually with some side branches; main branch overlying the midrib: Liriomyza strigata

4a blotchy part of the mine overlying the midrib: Liriomyza xanthocera

4b blotchy part of the mine not associated with the midrib: Liriomyza aterrima