Gall-former: The larva mines the leaves and stems. Tip of frond rolled upwards
into a loose, conspicuous mop-head involving many pinnae; inside
a white larva mines along rachis causing it to coil (Redfern et
al. (2002: 288, fig.
in the leaf tip, that is strongly contorted. An elongated white
egg shell is visible at the centre of the mass (Bladmineerders van Europa).
betuleti is the only Chirosia species to form galls (Griffiths).
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 de Meijere (1911), who gives an account
of the biology, and Ellis (Bladmineerders van Europa).
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).
Ackland in Chandler (1978)
did not indicate whether his host record was British or Foreign
and is therefore included under 'Hosts in Britain' and 'Hosts elsewhere'.
Hosts in Great Britain & Ireland:
of year - mines:
End May - early July (Bladmineerders van Europa).
of year - adults: Currently unknown.
in Great Britain & Ireland: Widespread in the south of Britain;
Cornwall, Wiltshire, Worcester, Hants, Norfolk, Merioneth (Mike Ackland,
pers. comm.), Warwickshire (Oversley Wood) (Robbins,
1991: 21). Berkshire (VC22), Cardiganshire (VC46), Cheshire (VC58), Denbighshire (VC50),
East Norfolk (VC27), East Suffolk (VC25), Easterness (VC96), Elgin, Flintshire (VC51), Herefordshire (VC36),
Merionethshire (VC48), Mid Perthshire (VC88), Mid-west Yorkshire (VC64), Montgomeryshire (VC47), North Lincolnshire (VC54), North Somerset (VC6), Oxfordshire (VC23), Shropshire (VC40), South Devon (VC3),
South Hampshire (VC11), South-west Yorkshire (VC63), Staffordshire (VC39), Surrey (VC17), West Gloucestershire (VC34),
West Kent (VC16), West Suffolk (VC26) and Worcestershire (VC37) (NBN
recorded in the Republic of Ireland (Michelsen in Fauna Europaea).
NBN Grid Map:
elsewhere: The Netherlands (Bladmineerders van Europa), Czech Republic, Denmark, Finland, ? French mainland,
Germany, Italian mainland, Norwegian mainland, Poland, Russia -
North and Northwest, Slovakia, Spanish mainland and Sweden (Michelsen in Fauna Europaea).
NBN Interactive Grid Maps of known host species:
British and Irish Parasitoids in Britain and elsewhere: Currently unknown.