Wingspan 7 to 9 mm. Similar to other members of the family. The wings are brown with white markings edged in black. The larva mines the leaves of Birch, causing a small (<15mm) tentiform mine. The larva is pale yellow or whitish with a pale brown head.  Pupation is in the mine in a papery cocoon

other Phyllonorycter on Birch; Parornix betulae.  P cavella has larger mines.  P anderidae has not been recorded in VC55, although it has been found in neighbouring counties; the larva has a darker brown head and the pupa is not in a cocoon.

Adult Leafmine

Photograph mine; check length of mine, and for presence of cocoon inside

This species can be found almost anywhere where the foodplant, Birch is present.

There are two generations with adults flying in May and again in August.

The larvae are present in July, and more commonly in September and October.

Widespread and fairly common throughout the British Isles. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as common.

It appears to be uncommon in Leicestershire and Rutland, where there are few records. L&R Moth Group status = D (rare or rarely recorded).

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

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