Wingspan 10 to 12 mm. The adults resemble several other Coleophora species, dissection required to confirm ID. The larva feeds on Juncus rush species including Soft-rush, Hard Rush and Compact Rush.

Adult Case Larva

Occurring wherever Juncus rush species grow and seed, up to 660 metres above sea level in some years.

Flight period June and July, possibly late April and May, at sunrise, dusk and night.

The larval case is indistinguishable from C. glaucicolella. There are subtle larval differences, but rearing & dissection is recommended.

It is the most widespread and common British Coleophora species. 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 (rare or rarely recorded).

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

https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/lepidoptera/ditrysia/gelechioidea/coleophoridae/coleophora/coleophora-alticolella/