The leaf and stem mines of British flies and other insects
 

(Coleoptera, Diptera, Hymenoptera and Lepidoptera)

by Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds

N.B. Links to the latest version of 'Leafminers and plant galls of Europe' are being edited

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SPINACIA. Spinach. [Chenopodiaceae]


Spinach (Spinacia oleracea) was introduced and is cultivated in Britain.

Nine British miners are recorded on Spinacia.

The polyphagous agromyzid Liriomyza trifolii has been recorded in quarantine in Britain (Pitkin & Plant in British leafminers). See also Liriomyza species in Glasshouses and/or Quarantine Interceptions.

Although previously recorded as a miner on Spinacia in Britain and elsewhere, Botanophila fugax is a common saprophagous species, the larvae normally feeding in the soil (Griffiths, pers. comm.).



Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Spinacia


1a > Leaf-miner: Leaf and stem miner: Eggs are scattered individually over the leaf upper surface; they are only loosely attached to the plant. The egg shell has a honeycomb structure. The larva begins with first mining one of the top leaves completely out. Next the larva moves down to another leaf, by way of a tunnel made in the stem. In this way several leaves are mined out, completely and full depth. In the attacked part of the plant the stem has become translucent; the damage causes the plant tip to wilt. In the first mines almost no frass is to be found, further down it is deposited in coarse grains. Pupation generally outside the mine (Miles, 1953) (Bladmineerders van Europa).

On Agrostemma, Arenaria, Cerastium, Dianthus, Gypsophila, Lychnis, Saponaria, Silene, Spergularia, Stellaria and Vaccaria [Caryophyllaceae], Atriplex, Chenopodium, Spinacia [Chenopodiaceae], Phlox [Polemoniaceae] in Britain and/or elsewhere (records ambiguous). Also recorded on other hosts elsewhere. Known only from Warwick and West Ross in Britain, Europe, Japan, Canada and Alaska.

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

1b > Leaf-miner: The larva makes several full depth blotch mines (Bladmineerders van Europa).

Hosts in Britain unknown. On Atriplex, Beta, Chenopodium and Spinacia elsewhere.

Pegomya cunicularia (Rondani, 1866) [Diptera: Anthomyiidae].

1c > 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) (Bladmineerders van Europa). Mine indistinguishable from P. exilis or P. hyoscyami (Bladmineerders van Europa).

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 (British leafminers).

On Silene [Caryophyllaceae], Atriplex, Beta, Chenopodium and Spinacia [Chenopodiaceae] and possibly Solanum [Solanaceae] 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].

1d > Leaf-miner: Blotch mines, generally occupying an entire leaf, usually containing several larvae. Much, half deliquescent, green frass (Bladmineerders van Europa). Mine indistinguishable from P. exilis or P. hyoscyami (Bladmineerders van Europa).

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

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

1e > Leaf-mine: Mine indistinguishable from P. betae or P. hyoscyami (Bladmineerders van Europa).

Hosts in Britain unknown. On Chenopodium and Spinacia elsewhere. Pegomya exilis and Pegomya cunicularia were distinguished from Pegomya betae and Pegomya hyoscyami by Michelsen (1980). Material of both [the former species] had previously been assigned to those [two latter] species (Chandler, pers. comm.). It is not known whether any of this previously mis-identified material is British.

Pegomya exilis (Meigen, 1826) [Diptera: Anthomyiidae]

1f > Leaf-miner: A white linear-blotch mine, the linear section sometimes not detectable as it becomes enveloped in later blotch (Spencer, 1976: 162-3, figs 296-7).

Upper-surface, less often lower-surface, corridor, followed, and often overrun, by a large blotch. Even when the corridor is overun, it usually remains recognisable in the frass pattern. The mine looks whitish in the field. The blotch does not contain much frass, in the form of small black grains, dispersed and stuck to the floor of the mine. Feeding punctures upper-surface (always?). Pupation outside the mine (Bladmineerders van Europa).

A common miner, forming a white linear blotch mine (the blotch may obscure the linear portion of the mine) in both native and garden plants (British leafminers).The mine is also illustrated in the Encyclopedia of Life.

Puparium reddish brown

On Agrostemma, Dianthus, Lychnis, Saponaria, Silene, Stellaria [Caryophyllaceae] and Atriplex, Beta and Spinacia [Chenopodiaceae] in Britain. Widespread in Britain and continental Europe. Also Canada.

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

1g > Leaf-miner: A short, irregular, linear upper surface mine on any part of the leaf. Also recorded from young pods (Bland, 1997a).

Long corridor mine. As a rule the first part of the mine is lower-surface, the later part upper-surface. Often the loops are so dense that a secondary blotch is the result. Because upper- and lower-surface corridor segments often cross, the mine obtains a strange array of transparant patches. There is no association with the midrib. Frass in strings and thread fragments. Pupation outside the mine; exit slit in upper epidermis (Bladmineerders van Europa).

Mine not associated with the veins or midrib of the leaf (It is this character which enables distinction from another Agromyzid pest species - Liriomyza huidobriensis). The larvae may leave one leaf (if not large enough) and enter another leaf, via the petiole). It exits the leaf to pupate through a semi-circular slit in the upper surface of the leaf (British leafminers).

Polyphagous. On 119 plant genera in 31 plant families of which only 4 plant genera in 2 plant families, but not yet on Spinacia, in Britain. On Alisma elsewhere. Local, probably introduced to Britain. Widespread in continental Europe particularly in Botanical Gardens and glasshouses. Also recorded in Egypt.

Liriomyza bryoniae (Kaltenbach, 1858) [Diptera: Agromyzidae].

1h > 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) (Bladmineerders van Europa).

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

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

1i > Leaf-miner: Whitish blotches in the leaves (UKMoths). The mine begins as a short zigzagging corridor, that very soon becomes overrun by a large, perfectly transparent blotch. Frass in a big black central lump. In fresh mines something like primary feeding lines are recognisable, normally seen only in Diptera mines. Pupation external, exit a rather untidy hole (Bladmineerders van Europa). A large, whitish blotch sometimes occupying most or all of the leaf. The frass is mostly ejected from the mine. (British leafminers).

On Atriplex and Chenopodium, but not yet Spinacia, in Britain plus Amaranthus, Bassia and Spinacia elsewhere. Widespread in Britain and continental Europe

Chrysoesthia sexguttella (Thunberg, 1794) [Lepidoptera: Gelechiidae].



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