1a fleck mine; larva in a lobe case: Coleophora chamaedriella

1b very short mine, containing a puparium: Hydrellia griseola

1c full depth corridor or blotch; larva with chitinised head => 2

1d mine upper- or lower-surface; larva a maggot => 4

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

2a mine irregularly inflated; frass in a central spot: Dibolia depressiuscula (occurrence on this plant is doubtful)

2b mine, at least initially, corridor-like with frass in a central line => 3

3a mine originates from the leaf base or the midrib; larva without feet: Orthochaetes insignis

3b mine not connected to leaf base or midrib; larva with thoracic feet: Apteropeda globosa, orbiculata, splendida

4a pinnately branched corridor, main branch overlying the midrib: Liriomyza strigata

4b mine not pinnately branched, independent of the midrib; usually partly a secondary blotch => 5

5a initial corridor part closely follows the leaf margin: Phytomyza crassiseta

5b initial corridor part free from the leaf margin: Phytomyza veronicicola

5c see also: Phytomyza aphyllae