Key for the identification of the known mines of British
Diptera recorded on Suaeda

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).

See Key to non-Diptera.

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. On ? Agrostemma, ? Arenaria, ? Cerastium, ? Dianthus, ? Gypsophila, ? Lychnis, ? Saponaria, Silene, ? Spergularia, ? Stellaria, Vaccaria, Atriplex, ? Chenopodium, Spinacia and ? Phlox, but not yet on Suaeda, in Britain. 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

2

2a > Leaf-miner: 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 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 > Leaf-miner: Blotch mines, generally occupying an entire leaf, usually containing several larvae. Much, half deliquescent, green frass. Mine indistinguishable from P. exilis or P. hyoscyami.

On Atriplex, Beta and possibly Polygonum, but not yet on 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 > Leaf-miner: 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.

Blotch, mostly occupying almos the entire leaf, containing several larvae. Much, half-deliquescent, greenish-black frass. At the start of the mine at the leaf underside a group of some 5 elliptic egg shells, parallel to each other. However, the larvae can leave their mine and restart elsewhere, so mines without egg shells can occur as well. The larvae do not penetrate into the stem of the plant, neither is the mine full depth (compare Delia species). Mine indistinguishable from P. exilis or P. hyoscyami.

Makes a large upper surface whitish blotch, which can contain several larvae. The frass has a washed out appearance and is greenish. There may be several mines on a leaf and eventually the leaf will be mined and then shrivel up. To identify this miner adults must be reared.

On Silene, Atriplex, Beta, Chenopodium and ? Solanum, but not yet on Suaeda, in Britain and additional genera of Chenopodiaceae and Solanaceae elsewhere. Continental Europe and the East Palaearctic.

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

2d > Leaf-miner: Blotch.

On Suaeda in Britain and Atriplex, Suaeda and ? Spergularia elsewhere. Widespread in Britain including 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 > Leaf-miner: The mine starts as a long, narrow, winding corridor running towards the midrib, widening to a blotch. Usually upper-surface, but in small leaves also full-depth parts may occur. The blotch has broad lobes; in their ends most frass is accumulated in the form of green patches or clouds. Sometimes several larvae share mine. 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).

On ? Amaranthus, Cerastium, Lychnis, Myosoton, Nasturtium, Silene, Stellaria, Atriplex, ? Anthyllis, ? Lupinus, ? Medicago, ? Montia and ? Antirrhinum, but not yet on Suaeda, in Britain.

On Amaranthus, Lepidium, Moricandia, ? Rorippa, Agrostemma, Arenaria, Cerastium, 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].

2f > Leaf-miner: Broad mine of variable depth. Frass spread irregularly. Pupation usually internal, seldom external.

On ? Atriplex, ? Beta, ? Salicornia, ? Spergularia and ? Sueada in Britain plus Obione elsewhere. Also recorded in the Republic of Ireland (Zatwarnicki, 2004 in Fauna Europaea). Widespread in continental Europe.

Clanoneurum cimiciforme (Haliday, 1855) [Diptera: Ephydridae].