Cardaria whitetop, hoary cress
Often merged 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 => 4
1c galls, etc => Tables for all parasites per species
2a larva with prolegs; older larvae live free under the leaf; mine small, roundish: Plutella xylostella
2b no prolegs;larve mines livelong; mine not that small, a corridor => 3
3a larva without feet: Ceutorhynchus minutus
3b larva with thoracic feet: Phyllotreta nemorum
4a frass powdery, in green clouds in remote corners of the mine; mine in the end widened into an irregular blotch: Scaptomyza flava
4b frass black, in grains or strings; mine a corridor till the end => 5
5a corridor closely following the leaf venation => 6
5b corridor independent of the leaf veins => 7
6a larva: cephalic skeleton with three backwards pointing arms: Ophiomyia beckeri
6b cephalic skeleton with two backwards pointing arms: Liriomyza strigata
7a pupaption within the mine, in a, generally lower-surface, pupal chamber: Chromatomyia horticola
7b pupation external => 8
8a larva: rear spiraculum with 7-12 papillae: Liriomyza bryoniae
8b rear spiraculum with 3 papillae: Liriomyza brassicae
See also Amauromyza flavifrons (xenophagy?)