1a mine full depth; larva with chitinised head => 2

1b mine upper- or lower-surface; larva a maggot => 5

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

2a larva without feet; untidy, locally widened corridor: Orthochaetes setiger

2b larva with thoracic feet => 3

3a larva with prolegs; mijn small, irregular; older larvae live free => 4

3b larva without prolegs; mine larger, a clear corridor; larvae mine all their life (three chhrysomelids, no characters known to distinguish mines or larvae): Apteropeda globosa, orbiculata, splendida

4a larva: segment 10 with an anal comb: Cnephasia asseclana

4b no anal comb: Cnephasia stephensiana

5a narrow, hardly widening corridor followed (and often overrun) by a large blotch => 6

5b corridor from start to end => 9

6a larva: rear spiraculum with a large number of papillae: Phytomyza abdita (rare species, occurrence on this hostplant not certain)

6b rear spiraculum with 3 papillae => 7

7a frass in the corridor part in a broad green central band, very fine black granules at either side: Amauromyza labiatarum

7b no green central band; frass in black grains or strings => 8

8a frass in the corridor in strings, regularly alternating along the sides: Amauromyza lamii

8b frass here in untidily arranged thread fragments, towards the end more on grains: Amauromyza morionella

9a pinnately branched corridor, the main branch overlying the midrib; frass in strings; pupation outside the mine: Liriomyza strigata

9b corridor not pinnate, not associated with the midrib => 10

10a frass in isolated grains; puparium in the mine in a, usually lower-surface, pupal chamber; mine nevers forms a secondary blotch: Chromatomyia horticola

10b frass in strings; puparium formed outside the mine; often a secondary blotch: Liriomyza bryoniae