Wingspan about10 mm. A relatively unremarkable looking member of the Momphidae, M. langiella is however quite distinctive, with its fuscous ground colour and irregular-shaped white marking at around two-thirds.  The larva mines the leaves of Enchanter's-nightshade and Great Hairy Willowherb, initially in a gallery and then a blotch.  The blotch mines are transparent and white initially, with irregular clumps of frass. The larva is pale with dark head and pronotal mark

Mompha terminella also mines Enchanter's Nighshade, in spiral and looped galleries.  Several species of Mompha feed on willowherbs, and the mines (and host species) are hard to identify.

Adult leaf mine on Circaea on Epilobium

Backlit photographs of mine; note host.  The mine is best recorded on Enchanter's Nightshade (Circaea lutetiana); on Epilobium care is needed to identify host species and examine mine and larva; breeding out may be required

Woodland and occasionally gardens, especially where the larval food plants are present.

August through to April.

The larva mines the leaves of Enchanter's Nightshade and willowherbs in June and July, forming a whitish blotch with scattered frass.

Distributed locally in southern and western England and Wales, there are also scattered records from further north and in Ireland. In the Butterfly Conservation’s Microlepidoptera Report 2011 this species was classified as local.

The Leicester record of 27th March 2012 is the first for VC55 (Leicestershire and Rutland).

http://www.leafmines.co.uk/html/Lepidoptera/M.langiella.htm

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/ditrysia/gelechioidea/momphidae/mompha/mompha-langiella/