Wingspan 7 to 9 mm. At first glance the adult can appear devoid of markings, but on closer scrutiny, the pale greyish strigulae can be seen, as can the diagnostic basal streak, which usually extends more than half the forewing length.

The leaf mines on oak can be searched for from late autumn through winter, and it is relatively easy to rear the adult.  The species is difficult to identify from the mine alone, but the pupa has a distinctive arrangements of hooks at the very end, known as the 'cremaster'.  There is a key and description of these on Bladmineerders.nl (see 'Further Information' link below) and photos at https://mothdissection.co.uk/species.php?Tx=Phyllonorycter_quercifoliella

Other Oak Phyllonorycter

Adult Leafmine/pupa

Photograph adult, or frass covered cocoon when recording leafmine, or mine and pupal cremaster.

Areas where Oak is plentiful.

The moths are on the wing in April and May, and again in August and September.

The larval mine is a small blotch on the underside of a leaf of Oak.

Probably the commonest of the oak-feeding Phyllonorycters, this species is frequent throughout most of the British Isles. 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/P.quercifoliella.htm

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