Wingspan 12 to 14 mm. A small but distinctive species, resting in the characteristic erect posture typical of the genus Caloptilia. The forelegs are thickly scaled at the base, appearing 'feathered'. The body is chestnut brown with a noticeable white triangle midway along the body length.  The larva mines the leaves of Willow and Poplar, intially in a long narrow corridor usually on the undersurface of the leaf, then in a silvery blotch that developes into a tentiform mine with a brown epidermis. Finally the larva leaves the mine to live in a folded leaf margin or leaf-tip. 

Adult Leafmine

Photograph the mine and/or the leaf fold; note the host species in the Comments

Various habitats, especially places where the larval foodplants are found.

It flies in late June and July, and again from September onwards.

Fairly frequent throughout England and Wales. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as common.

Occasional in Leicestershire and Rutland. L&R Moth Group status = C (very scarce resident or rare migrant).

http://www.leafmines.co.uk/html/Lepidoptera/C.stigmatella.htm

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/ditrysia/gracillarioidea/gracillariidae/gracillariinae/caloptilia/caloptilia-stigmatella/