Note: Diptera larvae may live in a corridor mine, a corridor-blotch mine, or a blotch mine, but never in a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Pupation never in a cocoon. All mining Diptera larvae 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 larvae lie on their sides within the mine and use their pick-like mouthparts to feed on plant tissue. In some corridor miners frass may lie in two rows on alternate sides of the mine. In order to vacate the mine the fully grown larva cuts an exit slit, which is usually semi-circular (see Liriomyza huidobrensis video). The pupa is 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).

1a > A long narrow leaf mine which winds round the filiform leaves and can penetrate deeper into the parenchyma, becoming invisible. Pupation internal. Puparium reddish

On Triglochin maritimum and Triglochin palustre in Britain and elsewhere. Only recorded from Kent, Dorset, Suffolk in Britain. Widespread in continental Europe.

Liriomyza angulicornis (Malloch, 1918) [Diptera: Agromyzidae].

1b > Narrow corridor, spiralling around the leaves; often a part of the mine runs in the deeper parts. Frass in strings, but not in the typical pattern. Pupation as a rule within the mine.

On Triglochin in Britain. On Triglochin maritimum and Triglochin palustre elsewhere. Only known from Suffolk in Britain. Widespread in continental Europe.

Liriomyza latipalpis Hendel, 1920 [Diptera: Agromyzidae].