Leaf-mine: The initial mine is a blotch type. It then leaves this and makes folds on the leaf edge. The mine looks similar to Parornix finitimella and the larvae should be examined for identification of the mine. D. torquilella has legs concolorous with the body, whereas P. finitimella has black ringed legs (British leafminers, as Deltaornix torquillella).

The mine begins as a lower-surface epidermal gallery that widens into a blotch. Finally it becomes a small, only weakly inflated tentiform mine, quadrangular of triangular when it lies in a vein axil. The lower epidermis is whitish, unfolded, and rather transparent. The leaf tissue is eaten up to the upper epidermis. Frass packed in a corner of the mine. The older larva leaves the mine, then lives free under a leaf tip or margin that has been folded downwards, or in a leaf that is rolled into a pod (Bladmineerders van Europa).

Larva: Yellowish white/green; head light brown. Contrary to P. finitimella, living on the same hostplant, the rear margin of the head does not bear four patches, but two (sometimes indistinct), and the legs are not black, but yellowish green (Emmet, 1982a; Emmet, Watkinson and Wilson, 1985a) (Bladmineerders van Europa).

Pupa: Pupation in a cocoon under the folded edge of leaf (British leafminers, as Deltaornix torquillella).

Adult: The adult is illustrated in UKMoths (as Deltaornix torquillella). The male and female genitalia are illustrated by the Lepidoptera Dissection Group.

Hosts in Britain:

Hosts elsewhere:

Time of year - larvae: July to September (British leafminers, as Deltaornix torquillella).

Time of year - adults: The moths fly from May to July, and sometimes are attracted to light (UKMoths, as Deltaornix torquillella).

Distribution in Great Britain and Ireland: Britain and Northern Ireland (Karsholt and van Nieukerken in Fauna Europaea) including Anglesey, Bedfordshire, Caernarvonshire, Cambridgeshire, Cheshire, Derbyshire, East Cornwall, East Gloucestershire, East Kent, East Norfolk, East Suffolk, East Sutherland, Flintshire, Glamorgan, Hertfordshire, Huntingdonshire, Kincardine, Merionethshire, Middlesex, North Aberdeen, North Essex, North Hampshire, North Somerset, North Wiltshire, Northamptonshire, Shropshire, South Aberdeen, South Lancaster, South Wiltshire, Stafford, Surrey, Warwickshire, West Cornwall, West Gloucestershire, West Suffolk 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). See also British leafminers distribution map (as Deltaornix torquillella).

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, Belarus, Belgium, Corsica, Czech Republic, Danish mainland, French mainland, Germany, Greek mainland, Hungary, Italian mainland, Macedonia, Republic of Moldova, Norwegian mainland, Poland, Portuguese mainland, Romania, Russia - Central and South, Sicily, Slovakia, Sweden, Switzerland, The Netherlands and Ukraine (Karsholt and van Nieukerken in Fauna Europaea).

Also recorded in the Near East (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: