Dichotomous table for leafminers
1a mine usually starts in the leaf sheath; from there broad corridors enter the blade; at start of the mine an egg shell is visible; pupaption usually in a small separate mine; larva: mandible with 1 tooth: Hydrellia griseola
1b mine begins on the blade; no egg shell visible at the start; mandible with 2 teeth => 2
1c galls, etc => Tables for all parasites per species
2a several metallic black puparia in the mine, each anchored in the mine with with a strand of silk: Cerodontha incisa
2b puparia brown, generally formed outside the mine: Agromyza mobilis *
* See also the key to grass-inhabiting Agromyza larvae.