CAREX. Sedges. [Cyperaceae]

Ninety species of Carex are recorded in Britain, most of them native. They include Lesser Pond-sedge (C. acutiformis), Hairy Sedge (C. hirta), False Fox-sedge (C. otrubae), Carnation Sedge (C. panicea), Greater Tussock-sedge (C. paniculata), Pendulous Sedge (C. pendula), Cyperus Sedge (C. pseudocyperus), Bottle Sedge (C. rostrata), Wood-sedge (C. sylvatica) and Bladder-sedge (C. vesicaria).

Starved Wood-sedge (C. depauperata) is protected under Schedule 8 of the Wildlife and Countryside Act, 1981 and along with Few-flowered Sedge (C. pauciflora) is protected in Northern Ireland under Schedule 8 of the Wildlife (Northern Ireland) Order, 1985.

Ten Diptera miners, the agromyzids Cerodontha angulata, Cerodontha caricicola, Cerodontha eucaricis, Cerodontha scirpi, Cerodontha spinata, Cerodontha suturalis, Metopomyza flavonotata, Metopomyza scutellata and Metopomyza xanthaspis and the ephydrid Hydrellia griseola are recorded or tentatively recorded on Carex in Britain.

Three of the species recorded on Carex, Cerodontha angulata, Cerodontha suturalis and Hydrellia griseola, are also recorded or tentatively recorded on Scirpus in Britain. A single key is provided here to the mines of both host genera.

Elsewhere the agromyzids Cerodontha angulata, Cerodontha caricicola, Cerodontha eucaricis, ? Cerodontha geniculata, Cerodontha mellita, Cerodontha morosa, Cerodontha pseuderrans, Cerodontha scutellaris, Cerodontha spinata, Cerodontha suturalis, Metopomyza scutellata and Metopomyza xanthaspis, and the ephydrid Hydrellia griseola are recorded mining Carex.

Eleven non-Diptera miners are recorded on Carex in Britain (see below).

Elsewhere sixteen British non-Diptera miners are recorded on Carex (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Carex is provided in Bladmineerders van Europa. This includes Aphanisticus elongatus, Aphanisticus pusillus, Sedina buettneri, Monochroa arundinetella, Donacaula forficella, Elachista albidella, Elachista alpinella, Elachista biatomella, Elachista cinereopunctella, Elachista utonella, Elachista gleichenella, Elachista nobilella, Elachista bisulcella, Elachista obliquella, Elachista serricornis, Elachista humilis, Elachista atricomella, Hydrellia griseola, Metopomyza scutellata, Metopomyza xanthaspis, Metopomyza nigrohumeralis, Cerodontha angulata, Cerodontha pseuderrans, Cerodontha eucarici, Cerodontha geniculata, Cerodontha hirtae, Cerodontha spinata, Cerodontha caricicola, Cerodontha suturalis and Cerodontha morosa but not Cerodontha mellita, Cerodontha morosa, Elachista kilmunella, Elachista stabilella, Elachista adscitella, Elachista eleochariella or Elachista subalbidella.

N.B. The key to mines below includes mines recorded on Carex and Cyperus (Cyperaceae).

Key for the identification of British non-Diptera mines recorded on
Carex

Note: The larvae of mining Coleoptera, Hymenoptera and Lepidoptera may live in a corridor mine, a corridor-blotch mine, a blotch mine, a case, a rolled or folded leaf, a tentiform mine or sandwiched between two more or less circular leaf sections in later instars. Larva may pupate in a silk cocoon. The larva may have at least six legs (although they may be reduced or absent), a head capsule and chewing mouthparts with opposable mandibles (see video of a gracillarid larva feeding). Larvae of Hymenoptera and Lepidoptera usually also have abdominal legs (see examples). Frass, if present, never in two rows. Unless feeding externally from within a case the larva usually vacates the mine by chewing an exit hole. Pupa with visible head appendages, wings and legs which lie in sheaths (see examples).

1# > Leaf-miner: Details unknown.

Recorded on Carex in Britain and Carex and Eriophorum elsewhere. Britain and Northern Ireland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista kilmunella Stainton, 1849 [Lepidoptera: Elachistidae].

1a > Leaf-miner: Common reed and similar plants are the larval foodplant. The larva of this species has a peculiar habit of cutting part of a leaf to act as a raft, using this to float on the water to a new foodplant when necessary (UKMoths). Narrow, whitish, rather inflated corridor, sometimes several tens of centimeters long, running towards the leaf sheath. Frass in coarse grains, in a distinct central line. Now and then the larva makes a elongate case from leaf material and uses it to float to another hostplant. The case may stick for some time to the new host. The larva pupates in a stem, after having made an exit hole and closed it with silk (Bladmineerders van Europa).

Recorded on Phragmites australis, but not yet on Carex, in Britain and Carex, Glyceria and Phragmites elsewhere. Southern half of Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Donacaula forficella (Thunberg, 1794) [ Lepidoptera: Crambidae].

The mines of Elachista are insufficiently known to identify with any certainty and should be reared out.

1b > Leaf-miner: Gradually widening corridor, running either upwards or down. All frass is deposited in the earliest part of the mine. Often 2-3 larvae in a mine; in grasses with broad leaves sometimes more than one mine in a leaf (Bladmineerders van Europa).

Recorded on Deschampsia and Sesleria, but not yet on Carex, in Britain and Carex, Brachypodium, Calamagrostis, Deschampsia, Elymus, Festuca, Melica, Milium, Phleum, Poa and Sesleria elsewhere. Occurs in woodland habitats in England, Wales and locally in Ireland. Also recorded in the Channel Is. and the Republic of Ireland. Widespread in continental Europe.

 

Elachista adscitella Stainton, 1851 [Lepidoptera: Elachistidae].

1c > Leaf-miner: Corridor, 15 cm in the end, descending from the leaf tip. The mine is whtish and shallow at first, then becomes deeper, yellowish white, and more transparant. Pupation external; pupa, not in a cocoon, attached to the leaf (Bladmineerders van Europa).

Recorded on Carex, Eleocharis and Eriophorum in Britain and Carex, Eleocharis, Eriophorum, Scirpus, Calamagrostis, Deschampsia, Melica and Poa elsewhere. Northern Britain and Ireland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista albidella Nylander, 1848 [Lepidoptera: Elachistidae].

1d > Leaf-miner: The narrow mine begins a few cm below the tip of the leaf and runs downwards, sometimes along the leaf margin, sometimes in the center of the leaf. After hibernation the larva probably begins a new, similar mine, that becomes quite long, ending near the leaf base. Frass in a brown, regularly interrupted line. Pupation external; pupa attached to the leaf, not in a cocoon (Bladmineerders van Europa).

Recorded on Carex in Britain and elsewhere. Recorded in Britain and Northern Ireland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista alpinella Stainton, 1854 [Lepidoptera: Elachistidae].

1e > Leaf-miner: The larva begins in autumn the making of a long, narrow, corridor with a fine central line of grey frass. The corridor is straight or lightly wavy, and descends into the leaf sheath, or even into the stem or rootstock. The larva regularly leaves the mine to begin making a new one. Pupation external (Bladmineerders van Europa).

Recorded on Dactylis, but not yet on Carex, in Britain and Bromus, Carex, Dactylis, Melica and Milium elsewhere. Widespread in Britain, Ireland and continental Europe.

Elachista atricomella Stainton, 1849 [Lepidoptera: Elachistidae].

1f > Leaf-miner: Oviposition in a leaf axil. From there ascends a narrow corridor with a thin frass line. When the mine is 2-3 cm long the direction reverses. The result is an elongate, whitish, lightly inflated blotch with dispersed frass. Pupation external (Bladmineerders van Europa).

Recorded on Carex in Britain and elsewhere. East Sussex, Isle of Wight, Surrey and West Kent in Britain. Widespread in continental Europe.

 

Elachista biatomella (Stainton, 1848) [Lepidoptera: Elachistidae].

1g > Leaf-miner: Mine a descending and widening corridor, in the end an elongate blotch that may occupy the entire width of the leaf. The mine contracts somehat, narrowing the leaf. Frass in some elongate lumps in the centre of the mine (Bladmineerders van Europa).

Recorded on Deschampsia and Festuca, but not yet on Carex, in Britain and Carex, Brachypodium, Calamagrostis, Deschampsia and Festuca elsewhere. Widespread in Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista bisulcella (Duponchel, 1843) [Lepidoptera: Elachistidae].

1h > Leaf-miner: Mine generally descending from the leaf tip. The mine may occupy the space between leaf margin and midrib, but may also occupy the entire width of the leaf. Most frass accumulated in the oldest part of the mine. Pupation external; the pupa is attached to the leaf without a cocoon (Bladmineerders van Europa).

Recorded on Carex and Deschampsia plus Melica and Sesleria elsewhere. Britain and Northern Ireland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista cinereopunctella (Haworth, 1828) [Lepidoptera: Elachistidae].

1i > Leaf-miner: Mine upper-surface, starting a few cm under the tip of the leaf.A corridor first runs upwards, then doubles, widening all the while. The final part takes half the width of the leaf. The complete corridor is c. 6 cm long; except for the last centimetres it is completely filled with frass (Bland, 1996a). Buhr (1964) describes the mine on Eleocharis as follows: The larva makes in the finest, almost bristle-like culms, descending from a spikelet, an almost full depth corridor in which only here and there a few green stripes remain. Frass very loose, in extremely fine dots of threads. Pupation external; the pupa is attached to the rear of the leaf, without a cocoon. (Bladmineerders van Europa).

Recorded on Carex and Eriophorum in Britain plus Eleocharis elsewhere. Widespread in Britain and continental Europe. Also recorded in the Republic of Ireland.

 

Elachista eleochariella Stainton, 1851 [Lepidoptera: Elachistidae].

1j > Leaf-miner: The larva starts mining near a leaf tip in early autumn. This early mine approximates to being linear but is very erratic in its course. In earl winter the the larva usually moves to anew leaf. This second mine usually takes the form of a compact but irregularly brownish blotch close to or often within the area of purplish discoloration of the dying leaf tip. Occasionally the larva does not change mines but extends the one made in autumn. Pupation takes place in a concealed place amongst debris or between closely applied leaves (Bland and Knill-Jones, 1988). Egg generally at the underside of the leaf tip. From September until the following spring a narrow meandering corridor is made. Then gradually the corridor widens to nearly the full width of the leaf. Generally the larvae make a new mine in early winter, obviously without the initial corridor. The mine in this stage is brown and situated close to (or within) the red coloured dying apical part of the leaf. Frass in large elongate dark spots. Pupation external (Bladmineerders van Europa)

Mine of Elachista gleichenella on Carex flacca Image: Jean-Yves Baugnée (Bladmineerders van Europa)

Recorded on Carex and Luzula in Britain plus Deschampsia elsewhere. Widespread in Britain and continental Europe. Also recorded in the Republic of Ireland.

Elachista gleichenella (Fabricius, 1781) [Lepidoptera: Elachistidae].

1k > Leaf-miner: In spring a short corridor is made that is almost stuffed with frass. After hibernation this mine is vacated, and the larva then makes a number of elongated blotches, all descending from the leaf tip. These latter mines are whitish, with irregularly scattered frass (Bladmineerders van Europa).

Recorded on Carex, Agrostis, Anthoxanthum, Deschampsia, Festuca, Holcus and Poa in Britain plus Phalaris elsewhere. Widespread in Britain, Ireland and continental Europe.

Elachista humilis Zeller, 1850 [Lepidoptera: Elachistidae].

1l > Leaf-miner: In autumn the larva makes a long, brown corridor, and hibernates therein. In spring a new mine is made in another leaf. This one starts near the base of the blade, widens upwards, and finally forms an elongate yellowish irregular blotch of 3-5 cm in length. According to Martini (1912a) a characteristic of this species is the extreme precision with which the mine joins up with the length venation of the leaf. Pupation external; the pupa is attached to the mine without a cocoon (Bladmineerders van Europa).

Recorded on Carex in Britain and Carex, Eriophorum and Scirpus elsewhere. Britain including Banff, Chester, Easterness, Elgin, Mid Perth, North Essex and Stafford. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Elachista serricornis (Stainton, 1854) [Lepidoptera: Elachistidae].

1m > Leaf-miner: Mines downwards from leaf tip to stem. Makes a long narrow yellowish mine. May be up to four larvae in one leaf (British leafminers). Long narrow yellowish corridor, descending from the leaf tip to its base; at times 3-4 larvae in a leaf. Often several larvae in a communal mine. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Carex, Agrostis, Brachypodium, Deschampsia and Festuca in Britain and Agrostis, Avena, Brachypodium, Calamagrostis, Festuca, Milium and Poa elsewhere. Widespread in Britain and continental Europe.

 

Elachista stabilella Stainton, 1858 [Lepidoptera: Elachistidae].

1n > Leaf-miner: The larva creates a long narrow mine in the blade (UKMoths). Mine fairly translucent. It starts as a narrow corridor, running towards the leaf tip, but this almost invariably is overrun be a later, broad, descending corridor. The centre of the mine contains a vertical tube made of loose silk, in which the larva can quickly move up or down, and in which also most frass gets trapped. The sides of the mine are smooth (contrary to E. gangabella). Mines are difficult to find, because the leaves are wilting when larvae are present (Bladmineerders van Europa).

Recorded on Molinia, but not yet on Carex, in Britain and Carex, Arrhenatherum, Brachypodium, Calamagrostis, Melica, Molinia and Poa elsewhere.

 

Elachista subalbidella Schläger, 1847 [Lepidoptera: Elachistidae].

1o > Leaf-miner: The mine begins somewhere halfway the blade as an upwards running corridor. After a while the direction reverses, and an elongate blotch develops occupying half the width of the leaf. Frass, light green at first, grey later, concentrated in the lowest part of the mine. Pupation external (Bladmineerders van Europa).

Recorded on Carex in Britain and Carex, Festuca and Scirpus elsewhere. Britain including East Kent, North Hants and South Devon. Also recorded in the Republic of Ireland. Widespread in continental Europe.

 

Elachista utonella Frey, 1856 [Lepidoptera: Elachistidae].

1p > Leaf-miner: Rather narrow, long, corridor, of which the course largely is dictated by the venation; the mine may change direction (up/down). The larva may leave its mine and restart elsewhwere. Pupation within the mine; pupa in a white cocoon, just above the waterline (Bladmineerders van Europa).

Recorded on Carex in Britain and Carex and ? Phragmites elsewhere. Berkshire, East Norfolk, Oxford and South Wilts. Widespread in continental Europe.