Wingspan c. 7mm.
Distributed rather locally in parts of England and Wales, the adults of this species are rather similar in appearance to T. ekebladella, but are slightly smaller and plainer-looking.
The larvae form a reddish-brown blotch on the upper surface of the leaves of oak (Quercus), or sweet chestnut (Castanea sativa).
The mines have a dark circular blotch surrounded by a series of dark concentric rings or semicircles. Mines are visible from September onwards, and the larva overwinters in the mine. Adults emerge in June.
See also: Leafmine (British Leaf Mining Fauna)