1aa broad corridor widening into a blotch; mine full depth, transparant; larva with chitinised head: Bagous alismatis

1b corridor from begin to end (but may form a secondary blotch), initially lower-surface, later turning upper-surface; larva a maggot: Liriomyza bryoniae

1c one or more short galleries that enter the leaf from the petiole: Hydrellia albiceps, concolor, flavicornis, mutata, viridescens

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