Caloptilia falconipennella

Wingspan about 13mm.  The larva mines alder, starting with a short inconsipuous gallery, then a small lower surface tentiform blotch that over-runs the gallery and causes the leaf to contract slightly and the epidermis to turn brown.  The larva then leaves the mine and feeds within a folded and rolled leaf edge that is anchored with silk.  The larva is whitish with a pale brown head and lacks clear distinguishing features.

other moth species also fold or roll the edge of a leaf; check larva

Adult leafmine  

Photograph the mine and note host species

Areas where alder is present.

The adult moths emerge in September and overwinter in this stage, reappearing in the spring.

The larvae feed on alder, at first mining the leaf and creating a small, tent-like edge mine and then making a small number of folds on the leaf-edge which are 'anchored down' with silken strands.  The larva feeds within.

This is a rather rare and local species that is not often observed. Records suggest it has a fairly broad distribution, but is probably overlooked and may be more widespread than is currently known. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as Nationally Scarce B.

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/C.falconipennella.htm

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