Koeleria hair-grass
Koeleria cristata => Rostraria!
Dichotomous table for leafminers
2a case, immediately behind the mouth narrowed and somewhat bent: Coleophora lixella
2b case gradually widening begind the mouth, not bent: Coleophora ornatipennella
3a the mines of the following species are insufficiently diagnostic, and the larvae of many are not well known; a key cannot be made: Elachista albifrontella, argentella, baltica, herrichi, ozeini, triseriatella