1a mine upper- or lower-surface; larva a maggot => 2

1b mine full depth; larva with chitinised head => 5

1c fleck mine: Apterona helicoidella

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

2a large, pale, upper-surface blotch: Amauromyza verbasci

2b corridor mine => 3

3a corridor pinnately branched, main branch overlying the midrib: Liriomyza strigata

3b corridor not pinnate, independent of the midrib => 4

4a puparium in the mine; frass in isolated grains: Chromatomyia horticola

4b pupation outside the mine; frass in thread fragments: Liriomyza bryoniae

5a larva without feet; mine begins in the leaf base or in the midrib => 6

5blarva with thoracic feet, mine begins at a random position: Apteropeda orbiculata

6a pseudomine (larva living between the felt layer on top and lower epidermis); the larva pupates in a globular cocoon glued to the plant: Cionus olens.

6b normal mine; the larva pupates in the ground: Orthochaetes insignis