Leaf-miner and case-bearer: Larva mines leaves in autumn. Spring feeding is by grazing, usually on the underside of larger leaves, or feeding on the edges of small leaves. The full-grown case is black, pistol-shaped, 7 mm long (British leafminers), rather like the closely related C. ibipennella, which feeds on oak. Indeed, at one time they were believed to be conspecific (UKMoths).

Prior to hibernation the young larva makes full depth mines; in spring window feeding takes place. In its final stage the larva lives in a matt pistol case about 7 mm in length, that with a mouth angle of 30°-45° is standing obliquely on the leaf (Bladmineerders van Europa).

The case is also illustrated in the Encyclopedia of Life.

Larva: Described by Suire (1961a) (Bladmineerders van Europa).

Pupa: Details unknown.

Adult: The adult is illustrated in UKMoths. The male and female genitalia are illustrated by the Lepidoptera Dissection Group.

Hosts in Britain:

Hosts elsewhere:

Time of year - larvae: Late August to October, feeding again from April to May or early June (British leafminers).

Time of year - adults: June and July (UKMoths).

Distribution in Great Britain and Ireland: Distributed thinly in England and Wales as far north as Cumbria, and occupies heathy habitats where the foodplant grows (UKMoths) including Bedfordshire, Cambridgeshire, East Suffolk, Huntingdonshire, North Essex, South Wiltshire and West Kent (NBN Gateway - N.B. includes Watsonian Vice Counties having publicly available records that fall within or overlap the vice county border at 10km resolution or better i.e. a record for a vice county may relate to an adjacent vice county - for included datasets see NBN Grid map below).

Also recorded in the Republic of Ireland (Karsholt and van Nieukerken in Fauna Europaea).

NBN Grid map: Note that not all datasets on the NBN Gateway may be available on the map below. If you are an NBN Gateway registered user you can request access for missing datasets via the link 'Open interactive map in new window' below.

Distribution elsewhere: Widespread in continental Europe including Austria, Belgium, Czech Republic, Danish mainland, Estonia, Finland, French mainland, Germany, Hungary, Italian mainland, Latvia, Lithuania, Norwegian mainland, Poland, Romania, Russia - Central and South, Slovakia, Slovenia, Spanish mainland, Sweden, and The Netherlands (Karsholt and van Nieukerken in Fauna Europaea).

NBN interactive distribution map(s) of known host species in Great Britain and Ireland and elsewhere:

Parasitoids in Britain and elsewhere: Unknown.