Sparganium bur-reed
Dichotomous table for leafminers
1a corridor long and narrow, sometimes ending below the water line; older larva lives free in a case: Nymphula nitidulata
1b corridor broader, irregular, never ending submerged; older larva lives as a stem borer => 2
1c galls, etc => Tables for all parasites per species
2a larva: anal shield with a thickened rim, ending in two diverging teeth: Orthotelia sparganella
2b anal shield flat, untoothed: Globia sparganii