long irregular mine in late summer and autumn, overwintering low
in the stem, burrowing into a young leaf and continuing feeding
the following spring (Spencer,
least part of the mine consists of a very long, narrow, full depth
corridor that is almost free of frass. The larva moves from one
leaf to the other by way of the leaf sheath; most frass to be found
in the leaf sheaths (Bladmineerders van Europa).
Larva: The larvae of flies are leg-less maggots without a head capsule (see examples). They never have thoracic or abdominal legs. They do not have chewing mouthparts, although they do have a characteristic cephalo-pharyngeal skeleton (see examples), usually visible internally through the body wall.
The larva is described by Nowakowski (1973)
and Dempewolf (2001: 122).
Puparium: The puparia of flies are formed within the hardened last larval skin or puparium and as a result sheaths enclosing head appendages, wings and legs are not visible externally (see examples).
The puparium is unusually slender. Posterior spiracles club-shaped, with about 18 bulbs (Bladmineerders van Europa).
Hosts in Great Britain & Ireland:
of year - mines:
Probably from late autumn to May; hibernation in a leaf sheath (Bladmineerders van Europa).
of year - adults: Currently unknown.
in Great Britain & Ireland: Widespread in England. Huntingdonshire
(Woodwalton Fen), Suffolk (Barton Mills), Oxfordshire (Hall Copse)
and Cambridgeshire (Chippenham Fen) (Spencer, 1972b: 107); Cambridgeshire (VC29), East Sussex (VC14), Huntingdonshire (VC31), Northamptonshire (VC32), Oxfordshire (VC23) and South Hampshire (NBN
Distribution elsewhere: Widespread in continental Europe, including Austria, [former]
Czechoslovakia, Germany, Hungary, Denmark, Finland, Sweden (Spencer,
1976: 177) and France (Bladmineerders van Europa), Czech Republic, Estonia, Italian mainland,
Lituania, Poland, Slovakia and Spanish mainland (Martinez in Fauna Europaea).
NBN Interactive Grid Maps of known host species:
British and Irish Parasitoids in Britain and elsewhere: