Leaf-mine: A narrow linear mine commencing on lower surface (Spencer, 1972: 57; Spencer, 1976: 264).

Narrow brownish corridor, either upper- or lower-surface. Frass in strings or pearl chains. Pupation outside the mine. In small leaves the mine can be full-depth and occupy the entire leaf. At least in Achillea millefolium mines are generally found in the top half of the leaf (Bladmineerders van Europa).

Larva: Posterior spiracles each with 3 bulbs (Spencer, 1972: 57; Spencer, 1976: 264). The larva is illustrated in Bladmineerders van Europa.

Puparium: Yellow (Spencer, 1976: 264). The puparium is illustrated in Bladmineerders van Europa.

Hosts in Britain:

Hosts elsewhere:

Time of year - mines: August (Hering, 1957).

Time of year - adults: Unknown.

Distribution in Great Britain and Ireland: Probably widespread, at least in south. Records include London (Hampstead), Middlesex (Scratch Wood) (Spencer, 1972: 57) and Warwickshire (Coventry) (Robbins, 1991: 115); Cambridgeshire and Monmouthshire (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).

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 Sicily, Denmark, Finland, Norway, Sweden (Spencer, 1976: 263), The Netherlands, Belgium, Luxembourg (Bladmineerders van Europa), Germany (Spencer, 1976: 558), Belarus, Czech Republic, Estonia, French mainland, Germany, Hungary, Latvia, Lithuania, Norwegian mainland, Poland and Slovakia (Martinez in Fauna Europaea).

Also recorded in Canada (Alberta) (Spencer, 1976: 263).

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

Parasitoids in Britain and elsewhere: Unknown.