Ulmus minor Germany: Badenweiler
Mine small, very compactly wound, close to the midrib, with much frass and a comparatively long larval chamber.
Mines in September-October.
Mines like the ones shown above have been found in the Netherlands and southern Germany. They differ so strongly from those of B. albedinella and B. ulmifoliae that is seems improbable that they can be attributed to either species.