Lepidium cress, pepperweed
incl. Coronopus, Senebiera. See also Cardaria, that often is united with Lepidium.
Dichotomous table for leafminers
1a larva with well recognisable head; mine full depth, transparant => 2
1b larva a maggot; mine upper- or lower-surface, greenish when lighted from behind => 6
1c galls, etc => Tables for all parasites per species
2a larva with prolegs; older larvae live free; mine mostly quite small => 3
2b no prolegs; larve mines livelong; mine not that small, a corridor => 5
3a body of larva dark: Cnephasia incertana
3b body of larva ± bone coloured => 4
4a older larva live free under a leaf: Plutella xylostella
4b older larvae live in some leaves, held together with silk: Hellula undalis
5a larva without feet: Ceutorhynchus minutus
5b larva with thoracic feet: Phyllotreta nemorum
6a mine a corridor, in the end widening into an irregular blotch => 7
6b a corridor from start to end => 8
7a frass powdery, in green clouds in remote corners of the mine: Scaptomyza flava
7b frass black, in grains or strings: Liriomyza xanthocera
8a corridor pinnately branched, its main and side branches on top of the midrib and lateral veins: Liriomyza strigata
8b several short corridors, starting from the midrib: Ophiomyia beckeri
8c corridor independent of the leaf veins => 9
9a pupation within the mine, in a, generally lower-surface, pupal chamber: Chromatomyia horticola
9b pupation external => 10
10a larva: rear spiraculum with 7-12 papillae: Liriomyza bryoniae
10b rear spiraculum with 3 papillae: Liriomyza brassicae