Oviposition can take place in the leaf, where a short mine is formed.
The young larva feeds towards the mid-rib and down into the stem.
Alternatively a true mine can be formed in the stem before the larva
burrows deeper into the pith. Pupation external (Spencer,
larva bores in the pith of the stem, and eats this out while descending
as low as the root collar. But before that it makes a linear mine
in the green rind of the stem. Occasionally oviposition takes place
on a leaf, leading to a fine corridor (without frass) running towards
the midrib, and from there to the stem. The place where the larva
finally exits the stem for pupation is indicated by a red-ringed
hole (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.
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).
Yellowish. Posterior spiracles each with 3 elongate bulbs (Spencer,
Hosts in Great Britain & Ireland:
of year - mines: September.
of year - adults: June.
in Great Britain & Ireland: Recorded in Cambridge (Cambridge)
and Derby (Worthington) (Spencer, 1972b: 45). (NBN
elsewhere: Widespread in continental Europe including Denmark,
Finland, Sweden (Spencer, 1976:
160), The Netherlands (Bladmineerders van Europa), Germany (Spencer,
1976: 550), Belgium, Czech Republic, Lithuania, Poland, Slovakia
and Sweden (Martinez in Fauna Europaea).
NBN Atlas links to known host species:
British and Irish Parasitoids in Britain and elsewhere: Currently unknown.