Melampyrum cow-wheat
Dichotomous table for leafminers
1a short corridor, that seems to vanish into a thick vein; the larva finally lives as a stem borer: Phytomyza rostrata
1b irregular small mine, not associated with a vein; older larvae live free among spun leaves: Cnephasia asseclana
1c galls, etc. => Tables for all parasites per species