Wingspan about 8 mm.  It mines sallow leaves, creating tentiform mines. 

Phyllonorycter hilarella and P salicicolella.  The mines and larva cannot be distinguished.

Adult  Leafmine

Adult: Dissection is required to confirm records to full species.

Leafmine: Please rear through potential mines – the resulting adult should be retained for gen det.

Where the larval host plant occurs.

There are two generations of the moth, with leafmines being visible in July and again in September and October, and adults on the wing in May and June, and again in August. 

The species mines the leaves of Goat Willow, causing the upper surface of the leaf to fold quite dramatically.

Generally speaking a species of southern and central England. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as Nationally Scarce B.

Rare in Leicestershire and Rutland.  The Burbage Common record of 5 Nov 2021 was the first for VC55

http://www.leafmines.co.uk/html/Lepidoptera/P.dubitella.htm

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/ditrysia/gracillarioidea/gracillariidae/lithocolletinae/phyllonorycter/phyllonorycter-dubitella/