Pyracantha firethorn
The only species that regularly lives on Firethorn is Phyllonorycter leucographella. The other species in the key are either polyphagous on Rosaceae (Lyonetia clerkella) or species that primarily live on Hawthorn.
Dichotomous table for leafminers
1a tentiform mine or blotch without preceding corridor => 2
1b blotch with a clear preceding corridor: Stigmella hybnerella
1c corridor from start to end => 3
1d gallen etc => Tabellen voor alle parasieten per soort
2a upper-surface, silvery, blotch: Phyllonorycter leucographella
2b lower-surface, yellow green, tentiform mine: Phyllonorycter oxyacanthae
3a corridor < 10 mm, mostly hook-like, in a vein axil: Bucculatrix bechsteinella
3b corridor longer, not hook-like, winding freely through the leaf: Lyonetia clerkella
Not included in the key: Coleophora prunifoliae