This species has recently been separated from a very similar moth, Caloptilia robustella, and accurate identification of the adult moth is problematic.
Caloptilia alchimiella lays its eggs on Oak leaves, and the larvae 'mine' the leaves before subsquently forming 'cones' by folding the tips of the leaves and then continuing to feed on them from inside the structure they have created.
Their habitat is open woodlands and other areas with with Oak trees.
The wingspan of the Caloptilia alchimiella ranges between 10 and 13mm.
In Britain and Ireland this moth is widespread and common in areas where Oak trees are present.
The lavae over-winter as pupae inside oak leaf cones. Some adults also over-winter and fly again in early spring.
The larval foodplant of Caloptilia alchimiella is Oak leaves