It seems to be an awful autumn for Nepticulid mines so far. Hopefully things are just running late. One of the few species which seems to be reasonably easy to find at the moment is Stigmella plagicolella. This is also one of the easiest mines to identify as it is the classic 'tadpole' mine, with a narrow gallery leading to a blotch. It is found on Blackthorn and related species of Prunus.