Leaf-mine: The mine starts at or near the leaf edge and widens to a blotch with frass in long threads (British leafminers).

Large, white, full depth blotch along the leaf margin. Frass in long threads. Old mines wither and disintegrate, and cannot be found any more later in the summer (Bladmineerders van Europa).

Larva: The final instar larva has a dark brown head (British leafminers, as Eriocrania unimaculella), the base of which shows as two dark spots (UKMoths, as Eriocrania unimaculella).

Pronotum with a pair of large black papillae. Head light brown. Abdomen segment 2 laterally with a pair of tubercles (Bladmineerders van Europa).

Pupa: Details unknown.

Adult: The adult is illustrated in UKMoths (as Eriocrania unimaculella). The male genitalia, but not the female genitalia (check for update), are illustrated by the Lepidoptera Dissection Group (as Eriocrania unimaculella)

Hosts in Britain:

Hosts elsewhere:

Time of year - larvae: April - May (British leafminers).

Time of year - adults: The adults fly in sunshine during March and April (UKMoths).

Distribution in Great Britain and Ireland: Well distributed and relatively common over much of Britain (UKMoths) including Banff, Bedfordshire, Buckinghamshire, East Suffolk, East Sussex, East Sutherland, Glamorgan, North Aberdeen, North Essex, North Somerset, Shropshire, South Aberdeen, South Hampshire, South Lancaster, South Wiltshire, Stafford, Surrey, West Cornwall, West Kent and Worcestershire (NBN Gateway, as Eriocrania unimaculella - 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). See also British leafminers distribution map.

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, Latvia, Lithuania, Norwegian mainland, Poland, Romania, Russia - South, Slovakia, Sweden, Switzerland 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.