1ablotch mine, preceded or not by an initial corridor => 2

1b corridor mine from start to end => 7

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

2amine very clear in transparency; frass in a black lump; larva with chitinised head and feet (rare on spinach): Chrysoesthis sexguttella

2b mine greenish in transparency; frass greenish or blackish; larva a maggot => 3

3afrass as many very fine green grains along the outer margin of the mine or in lobular offshoots: Scaptomyza graminum

3bfrass very little, fine black grains scattered in the mine: Amauromyza flavifrons

3cfrass in irregular, big, often washed-out, black-green lumps => 4

4a mine starts from one egg at leaf upper-surface; mandible of full-grown larva with one tooth: Delia echinata

4bmine starts from a group of eggs at leaf lower-surface; mandible of full-grown larva with several teeth => 5

5alarva: lowest of the mandibular teeth exceptionally strong: Pegomya cunicularia

5blowest tooth not that oversized (nb: larva of Pegomya exilis is undescribed) => 6

6aangle between terminal and subterminal mandibular teeth almost right: Pegomya betae

6bthis angle very sharp: Pegomya hyoscyami

7acorridors originate from leaf base and/or midrib => 8

7bmine not associated with leaf base or midrib => 9

8alarva single: Botanophila fugax

8bseveral larvae together: Delia platura

9acorridor usually starts upper-surface, usually turns underside further on; most of the mines in basal half of leaf; corridor often runs along midrib for some length: Liriomyza huidobrensis

9bcorridor usually starts lower-surface, turning upper-surface further on; no association with lower half of the leaf or midrib: Liriomyza bryoniae