Caloptilia cuculipennella

Wingspan c.12 mm. The posterior tibiae are smooth above. Forewings are whitish, with numerous ochreous or brown strigulae finely irrorated with black ; an oblique fascia near base hardly reaching costa, a second before middle hardly reaching dorsum, a third beyond middle interrupted in disc, and a costal spot at 3/4 ochreous or brownish, finely spotted with black. Hindwings are dark grey. 

The larva mines the leaves of Ash and Privet.  On Ash, the larva makes a thin silvery gallery mine on the upper leaf surface which causes a slight upward fold of the leaf-edge.  It then leaves the mine and feeds inside a cone caused by a double leaf-fold at the tip, eventually pupating inside.

Adult leaf mine/folds

Adults should be clearly photographed.

Larval stage: photograph leafmine and fold, or leaf cone 

Adult July-September. 

The larvae initially create a mine on either Privet or Ash, and then form two successive cones by rolling a leaf.

Although having a fairly wide distribution over much of the British Isles, this is a scarce species, and not often encountered. In the Butterfly Conservation's Microlepidoptera Report 2011 this species was classified as Nationally Scarce A.

Rare in Leicestershire and Rutland, but a number of VC55 records in 2021 suggest that the species may be increasing in our area..

http://www.leafmines.co.uk/html/Lepidoptera/C.cuculipennella.htm

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