Leaf-mine: The mine is underside, about 25 mm long, often from midrib to margin of leaf. The lower epidermis appears smooth. There may be several mines in a leaf (British leafminers).

Large, lower-surface tentiform mine, often occupying the entire space between two side veins, from the midrib almost to the leaf margin, Lower epidermis without clear folds.The larva is grey (all other phyllonorycters on Alder are white). Pupa in a light brown cocoon that is fastened to the roof of the mine. The cocoon is entirely free of frass: all frass is accumulated in the inner corner of the mine (Bladmineerders van Europa).

The mine is also illustrated in UKMoths.

Larva: The larva is illustrated in Bladmineerders van Europa.

Pupa: Cremaster with only one pair of spines; mesonotum without a pit at the rear margin. The cremaster is illustrated in British leafminers and Bladmineerders van Europa.

Adult: The adult is illustrated in UKMoths. The genitalia are not illustrated by the Lepidoptera Dissection Group (check for update).

Hosts in Britain:

Hosts elsewhere:

Time of year - larvae: September - October (British leafminers).

Time of year - adults: The moth is believed to have only a single generation, flying in July and August, though bred specimens will emerge in spring if kept indoors (UKMoths).

Distribution in Great Britain and Ireland: Widespread in Britain including Bedfordshire, Brecon, Buckinghamshire, Caernarvonshire, Cardiganshire, Cheshire, Denbighshire, Derbyshire, Dorset, East Norfolk, East Suffolk, East Sutherland, Easterness, Glamorgan, Herefordshire, Merionethshire, Middlesex, Monmouthshire, North Essex, North Somerset, North Wiltshire, Shropshire, South Aberdeen, South Lancaster, South-west Yorkshire, Stafford, West Lancaster, West Norfolk, West Suffolk, Westmorland and Worcestershire (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 Fleet, Hampshire (British leafminers). 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 Albania, Austria, Belgium, Bulgaria, Czech Republic, Danish mainland, Estonia, Finland, French mainland, Germany, Hungary, Italian mainland, Latvia, Lithuania, Macedonia, Norwegian mainland, Poland, Portuguese mainland, Romania, Russia - Central and Northwest, Sardinia, Slovakia, Spanish mainland, Sweden, Switzerland, The Netherlands, Ukraine and Yugoslavia (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.