Dichotomous table for leafminers
1a mine begins (usually in the centre of the leaf) with a number of close, intestine-like, loops; frass partly in a long thread; larva solitary: Agromyza anthracina
1b mine, usually at the leaf margin, without an intestine-like start; frass not in a thread; larvae generally communal => 2
1c galls, etc => Tables for all parasites per species
2a larva: the anterior arm of the cephalic skeleton two-coloured: frontal half dark brown, proximal part red brown: Agromyza reptans
2b this arm uniformly dark brown: Agromyza pseudoreptans
In Slovenia also Agromyza flaviceps has been reported from Urtica urens.