Wingspan 9 to 10 mm. The adults are difficult to separate from some Parornix species, especially Parornix finitimella, and genitalia examination is usually necessary to identify them.

The two mines are identical, but the larvae are quite different; Parornix torquillella is green with green legs, P. finitimella grey with blackish legs.

Adult leaf mine/fold

Only tenanted leaf-mines can be recorded.  Photographs must show the mine on the leaf, and the larva clearly showing the colour of front (thoracic) legs

Areas where Blackthorn is present.

The moths fly from May to July, and are sometimes attracted to light.

The main foodplant of this species is Blackthorn in common with its close relative, Parornix finitimella. 

Widespread and fairly frequent in Britain. 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 Possibly rarely recorded due to problems of identification.

http://www.leafmines.co.uk/html/Lepidoptera/D.torquillella.htm

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