Wingspan 10 to13 mm. Caloptilia alchimiella was recently separated from Caloptilia robustella and the two species are very similar (see recording advice).

The mines of the two species are very similar.  Initially this is a short gallery leading to a blotch, and then both species form leaf cones by folding down the leaf-tip. 

Adult Leafmine/fold for aggregate

To be certain of identification to species level, dissection of genitalia is necessary.  Where dissection has not taken place, records should be submitted as Caloptilia robustella - alchimiella agg.

Often associated with Oak.

The flight period (combined for the two species) is from May to October, and the moths can sometimes be attracted to light.

Fairly frequent and widespread as an aggregate in Britain.

Fairly frequent as an aggregate in Leicestershire and Rutland.