1a at the start of the mine (often inside a leaf sheath) at the outside an egg shell; larva: mandible with 1 tooth: Hydrellia griseola

1b no egg shell visible; mandible with at least 2 teeth => 2

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

2a puparium in the mine; cephalic skeleton of Phytomyzinae-type => 3

2b pupation outside the mine; cephalic skeleton of Agromyzinae-type => 5 *

3a puparium orange brown; front spiracula penetrate the epidermis: Chromatomyia nigra

3b puparium metallic black, not connected to the outside world=> 4

4a larva: the black warts at the outside of the rear spiracula small, without a ‘root’: Cerodontha incisa

4b these warts large, with a deep, black ‘root’: Cerodontha pygmaea

5a larva: rear spiracula touch each other: Agromyza albipennis

5b rear spiracula separated by at least their own diameter => 6

6a larva: ventrally, behind the mandibles, a field with fine low spines; mandible with 2 teeth: Agromyza nigrella

6b no such field; mandible with 4 teeth (occurrence on this host plant uncertain): Agromyza nigripes