Larva forms an external stem mine which quickly turns black. Pupation
internal, puparium projecting out of mine (Spencer, 1972b: 52; Spencer, 1976:
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 Dempewolf (2001:
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).
Dark, posterior spiracles conspicuous enlarged, laterally extended
processes, each with up to 40 minute bulbs (Spencer, 1972b: 52; Spencer, 1976:
The larvae occur most commonly on plants actually growing in water
(Spencer, 1976: 276).
Hosts in Great Britain & Ireland:
of year - mines: Currently unknown.
of year - adults: June.
in Great Britain & Ireland: Widespread in northern Britain
including Stafford (Newcastle-under-Lyme) (Spencer, 1972b: 52); Glamorgan (NBN
Distribution elsewhere: Widespread in continental Europe including Denmark,
Finland and Sweden (Spencer,
1976: 276), Germany (Dempwolf,
2001: 153), Czech Republic, Estonia, French mainland, Lithuania,
Poland and The Netherlands (Martinez in Fauna Europaea).
recorded in Alaska (Spencer,
NBN Atlas links to known host species:
British and Irish Parasitoids in Britain and elsewhere: