| Leaf- 
 and stem-mine: 
 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,  
 1976: 160). The 
 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,  
 1976: 160). Hosts in Great Britain and Ireland: Hosts 
 elsewhere: Time 
 of year - mines: September. Time 
 of year - adults: June. Distribution 
 in Great Britain and Ireland: Recorded in Cambridgeshire (Cambridge) 
 and Derbyshire (Worthington) (Spencer,  1972b: 45). Distribution 
   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 (Fauna Europaea). NBN Atlas links to known host species: British and Irish Parasitoids in Britain and elsewhere: Currently unknown. |