A slender twig gall up to 25 x 8 mm with a single chamber (see Redfern
et al., 2002: 320, fig. 260).
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.
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).
Greyish black (see Redfern
et al., 2002: 320, fig. 261).
adults, including the halteres, are uniformly black, as in other
British species of Hexomyza.
Hosts in Great Britain & Ireland:
of year - galls: May-June.
of year - adults: June.
in Great Britain & Ireland: Berkshire (Silwood Park) (Spencer,
NBN Grid Map:
elsewhere: Western Europe including Austria, Sicily (Spencer,
1990: 139), Czech Republic, Germany, Spanish mainland and The
Netherlands (Martinez in Fauna Europaea).
NBN Interactive Grid Maps of known host species:
British and Irish Parasitoids in Britain and elsewhere: Currently unknown.