Wingspan 5 to 6 mm. The larva mines the leaves of Birch. The leafmine is similar in appearance to that of S. lapponica, but has a black central line of frass throughout, unlike that species. The adult moths are similar to several other species in the group, and it may not be possible to identify adult to species level even by gen det.  

Stigmella lapponica also has narrow linear frass, but only in later part of mine

Adult Leafmine

Adult: It may not be possible to identify adult to species level even by gen det.  

Leafmine: Photographs required including a backlit image to show frass pattern. Please state host plant when adding your record.

Wherever Birch is found.

The adults are on the wing during May, and the leafmines can be found from June into August.

This is a single-brooded species.

Distributed widely across much of the British Isles. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as common.

Infrequently recorded in Leicestershire and Rutland.

http://www.leafmines.co.uk/html/Lepidoptera/S.confusella.htm

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/monotrysia/nepticuloidea/nepticulidae/stigmella/stigmella-confusella/