is laid beneath the epidermis on the upper leaf surface. Larva mines
in basal leaves. Pupation internal (Spencer,
branched corridors, radiating from the leaf base, often deep in
the plant tissue. The larva can migrate from one leaf to the other
through the petioles. Frass concentrated in the lowest, basal part
of the mine; there also the pupation takes place (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 de Meijere (1925),
Süss (1971) and Dempewolf
(2001: 77). Posterior spiracles
on distinct stalks, each with an ellipse of 9-11 bulbs (Spencer,
1976: 74 (fig. 94)).
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).
Pale whitish-yellow; posterior spiracles on distinct stalks, each
with an ellipse of 9-11 bulbs (Spencer,
1976: 74 (fig. 94)).
A serious pest of cultivated chicory in Belgium and The Netherlands
frquently introduced into Britain. The mining activity is detectable
from the reddish discolouration of the white leaves (Spencer, 1972b: 25).
Hosts in Great Britain & Ireland:
of year - mines: Larval feeding in the first generation can
last from 18-25 days but this is reduced later in the summer.
of year - adults: Currently unknown.
in Great Britain & Ireland: Uncommon, but widespread. Devon
(Lyme Regis), Dunbarton (Cardross), London, Cambridge (Cambridge,
on chicory introduced from Belgium or the Netherlands) (Spencer, 1972b: 25) and Warwickshire (Robbins,
NBN Grid Map:
Distribution elsewhere: Widespread in continental Europe including Denmark, Finland,
Sweden, Spain, Italy, [fomer] Yugoslavia (Spencer,
1976: 73-4), The Netherlands (Bladmineerders van Europa), Belgium (de
Bruyn and von Tschirnhaus, 1991), Germany (Spencer,
1976: 452; Dempewolf, 2001:
77), Austria, Czech Republic, European Turkey, French mainland,
Hungary, Lithuania, Poland, Slovakia and Yugoslavia (Martinez in Fauna Europaea).
extending eastwards to Tadzhik S.S.R and Uzbek S.S.R. (Spencer,
NBN Interactive Grid Maps of known host species:
British and Irish Parasitoids in Britain and elsewhere: