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 > Leaf and stem miner. Apart from mining leaves the stems are excavated. Oviposition takes place on the tips of shoots. The larva at first mines strip-like full depth corridors in the apical leaves, going then into the stem, which it hollows out, so that it becomes translucent. It then searches out leaves further down in which initially it mines depositing frass in strips, but then in blotches. The corridors often lie in one half of the leaf and can be branched. In the blotches the frass is irregularly scattered. Pupation is in the hollow stem or in the ground.

Host records ambiguous. Recorded on ? Agrostemma, ? Arenaria, ? Cerastium, ? Dianthus, ? Gypsophila, ? Lychnis, ? Saponaria, Silene, ? Spergularia, ? Stellaria, Vaccaria, Atriplex, ? Chenopodium, Spinacia and ? Phlox, but not yet on Salicornia or Suaeda, in Britain. Recorded on Amaranthus, Agrostemma, Arenaria, Cerastium, Dianthus, Gypsophila, Lychnis, Saponaria, Silene, Spergularia, Stellaria, Vaccaria, Atriplex, Chenopodium, Spinacia, Phlox and Primula elsewhere. Recorded from Warwick and West Ross in Britain. Widespread in continental Europe.

Delia echinata (Seguy, 1923) [Diptera: Anthomyiidae].

1b > Leaf miner.

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2a > A white linear-blotch mine, the linear section sometimes not detectable as it becomes enveloped in later blotch (Spencer, 1976: 162). Puparium reddish brown

On numerous genera of Caryophyllaceae and Chenopodiaceae, including Atriplex, but not yet on Salicornia or Suaeda, in Britain. Widespread but local in Britain. Widespread and not uncommon in much of Europe. Also recorded in Canada.

Amauromyza flavifrons (Meigen, 1830) [Diptera: Agromyzidae].

2b > Blotch mine, generally occupying an entire leaf, usually containing several larvae. Much, half deliquescent, green frass

On Atriplex, Beta and possibly Polygonum, but not yet on Salicornia or Suaeda, in Britain and additionally Silene and Spinacia [Caryophyllaceae], Chenopodium, Atropa, Hyoscyamus and Solanum [Solanaceae] in continental Europe. Only recorded from Warwick in Britain. Also recorded in the Republic of Ireland, Europe, the East Palaearctic and Nearctic Regions.

Pegomya betae (Curtis, 1847) [Diptera: Anthomyiidae].

2c > Large blotch mine, often with several larvae, beginning with a short deeper corridor at a single egg shell on the surface of the leaf. The broad deep corridor later ends in a blotch but can be recognised (beneath the blotch) by its greater depth. Mine predominantly dorsal or ventral, greenish in transmitted light. Frass grains irregularly scattered except in the initial corridor.

On Silene, Atriplex, Beta, Chenopodium and possibly Solanum, but not yet on Salicorniaor Suaeda, in Britain and additional genera of Chenopodiaceae and Solanaceae elsewhere. Known only from Inner Hebrides, Ayr and Warwick in Britain. Also recorded in continental Europe and the East Palaearctic.

Pegomya hyoscyami (Panzer, 1809) [Diptera: Anthomyiidae].

2d > Blotch mine.

On Suaeda, but not yet on Atriplex or Salicornia, in Britain and Atriplex, Suaeda and ? Spergularia elsewhere. Widespread in Britain incluidng Anglesey, Dorset, East Kent, East Sutherland, Easterness, North Devon, Pembrokeshire, South Devon, West Norfolk, North Uist. Widespread in continental N.W, Europe

Botanophila depressa (Stein, 1907) [Diptera: Anthomyiidae] ,

2e > A long, narrow, winding corridor running towards the midrib, widening to a blotch. Pupation usually in the soil, less often in the leaf (and then generally not in the mine itself but in a small separated mine, that may even be made in the petiole)

Mine of Scaptomyza graminum on Cerastium glomeratum Image: Jean-Yves Baugnée (Bladmineerders van Europa)

On ? Amaranthus, ? Rorippa, Cerastium, Lychnis, Myosoton, Silene, Stellaria, Atriplex, ? Anthyllis, ? Lupinus, ? Medicago, ? Montia and ? Antirrhinum, but not yet on Salicornia or Suaeda, in Britain and Amaranthus, Lepidium, Moricandia, ? Rorippa, Agrostemma, Arenaria, Cerastium, Coronaria, Corrigiola, Cucubalus, Dianthus, Gypsophila, Lychnis, Moehringia, Myosoton, Polycarpon, Saponaria, Silene, Spergularia, Stellaria, Vaccaria, Viscaria, Atriplex, Beta, Chenopodium, Obione, Salicornia, Spinacia, Anthyllis, Lupinus, Medicago, Allium, Montia, Portulaca and Antirrhinum elsewhere. Widespread in Britain and continental Europe.

Scaptomyza graminum (Fallén, 1823) [Diptera: Drosophilidae].