Arrhenatherum [Poaceae]

ARRHENATHERUM. False Oat-grass. [Poaceae]

Two species of Arrhenatherum are recorded in Britain, including False Oat-grass (Arrhenatherum elatius), a native species.

Eleven Diptera miners, the grass-feeing agromyzids Agromyza albipennis, Agromyza nigrociliata, Agromyza rondensis, Cerodontha flavocingulata, Cerodontha pygmaea, Chromatomyia fuscula, Chromatomyia nigra, ? Liriomyza graminivora, Liriomyza phryne and Liriomyza pusio and the polyphagous ephydrid Hydrellia griseola, are recorded on Arrhenatherum in Britain. Miners on grasses should be reared, whenever possible, to confirm their identity.

Elsewhere the agromyzids Agromyza albipennis, Agromyza nigrociliata, Agromyza nigrella / Agromyza mobilis, Agromyza rondensis, Cerodontha flavocingulata, Cerodontha pygmaea, Chromatomyia fuscula , Chromatomyia nigra, Liriomyza flaveola, Liriomyza phryne and Liriomyza pusio; and the ephydrid Hydrellia griseola are recorded mining Arrhenatherum.

One non-Diptera miner, Elachista rufocinerea, is recorded on Arrhenatherum in Britain (see below).

Elsewhere six additional British non-Diptera miners are recorded on Arrhenatherum (see below).

The gelchiid Helcystogramma rufescens spins grass blades and feeds inside the spiral spinning, causing whitening of the grass blade tip.

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Arrhenatherum is provided in Bladmineerders van Europa. This includes Elachista spp. (see below), Hydrellia griseola, Agromyza albipennis, Agromyza nigrociliata, Agromyza rondensis, Agromyza nigrella, Agromyza mobilis, Cerodontha pygmaea, Chromatomyia nigra, Chromatomyia fuscula, Liriomyza flaveola, Liriomyza pusio, Liriomyza phryne and Liriomyza graminivora but not Cerodontha flavocingulata .

N.B. The key to mines below includes mines recorded on Arrhenatherum, Brachypodium and Molinia (Poaceae).

Key for the identification of the mines of British Diptera recorded on
Arrhenatherum, Avenula, Brachypodium and Molinia

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).

1# > Leaf-miner: Details of mine unknown. Pupation external.

On Arrhenatherum, Dactylis and Holcus, but not yet on Avenula or Brachypodium, in Britain and additional grasses elsewhere. Widespread in England and Europe.

Liriomyza phryne Hendel, 1931 [Diptera: Agromyzidae].

1a > Leaf-miner: Pupation internal.

1b > Leaf-miner: Pupation external.

2a > Leaf-miner: Long, narrow, whitish mine. Pupation internal. Puparium yellowish brown, anterior spiracles projecting through the epidermis.

On numerous genera of grasses, including Arrhenatherum, Avenula and Brachypodium, but not yet on Molinia, in Britain and additional grasses elsewhere. Widespread and common throughout British Isles and much of Europe. Also recorded in Canada, western U.S.A. and Japan.

Chromatomyia nigra (Meigen, 1830) [Diptera: Agromyzidae].

2b > Leaf-miner: Narrow whitish mine, with frass in distinct black lumps. Pupation internal

On Arrhenatherum, Holcus, Milium and Phleum, but not yet on Brachypodium, in Britain and additional grasses elsewhere. Recorded in Scotland and Widespread in continental Europe. Also recorded in Canada.

Chromatomyia fuscula (Zetterstedt, 1838) [Diptera: Agromyzidae].

2c > Leaf-miner: Irregular mine, locally shallow, elsewhere much deeper, giving it a mottled appearance. In broadleaved plants the mine often begins as a blotch with stellate extensions, but sometimes as a very fine, shallow corridor. In grasses the mine often begins in the leaf sheath. The frass is very fine-grained, initially scattered, later in aggregates.

Mine of Hydrellia griseola on Glyceria fluitans. Image: Willem Ellis (Source: Bladmineerders van Europa)

Mine of Hydrellia griseola on Glyceria fluitans
Image: Willem Ellis (Bladmineerders van Europa)

On ? Alisma, ? Damasonium, ? Sagittaria, ? Bellis, ? Rorippa, Tropaeolum , ? Lychnis, ? Stellaria, ? Carex, ? Cyperus, ? Scirpus, ? Hydrocharis, ? Stratiotes, ? Lamium, ? Lemna, ? Allium, Arrhenatherum, ? Polygonum, ? Potamogeton, ? Veronica, ? Typha, but not yet on Avena, Avenula or Brachypodium, in Britain and ? Alisma, ? Damasonium, ? Sagittaria, ? Bellis, ? Rorippa, Tropaeolum, Lychnis, ? Stellaria, Carex, ? Scirpus, Trifolium, ? Hydrocharis, Lamium, ? Lemna, Allium, Papaver, Agrostis, Alopecurus, Apera, Arrhenatherum, Avena, Avenula, Brachypodium, Briza, Bromus, Calamagrostis, Dactylis, Desmazeria, Digitaria, Echinochloa, Eleusine, Elymus, Festuca, Gaudinia, Glyceria, Holcus, Hordeum, Lagurus, Lolium, Panicum, Phalaris, Phleum, Phragmites, Poa, Secale, Setaria, Triticum, ? Polygonum, ? Potamogeton, Veronica, ? Typha and Verbena elsewhere. Widespread in England. Also recorded in the Republic of Ireland. Widespread in the Palaearctic region. Also recorded from Nearctic and Australasian Regions.

Hydrellia griseola (Fallén, 1813) [Diptera: Ephydridae].

2d > Leaf-miner: Larvae feed singly, forming an upper surface linear-blotch mine. Pupation either internal or external. Puparium reddish, brown or black, loosely glued to the leaf.

Mine of Agromyza albipennis on Phalaris arundinacea. Image: Willem Ellis (Source: Bladmineerders van Europa)

Mine of Agromyza albipennis on Phalaris arundinacea
Image: Willem Ellis (Bladmineerders van Europa)

On Arrhenatherum, Brachypodium, Bromus, Dactylis, Glyceria, Holcus, Hordeum, Milium, Phalaris and Poa, but not yet on Avena or Molinia in Britain and additional grasses elsewhere. Widespread and common in Britain. Also recorded in the Republic of Ireland. Very common in western Europe and recorded in Canada.

Agromyza albipennis Meigen, 1830 [Diptera: Agromyzidae].

3a > Leaf-miner: A single larva in mine.

3b > Leaf-miner: More than one larva in mine.

4a > Leaf-miner: A lower surface mine. Normally pupation in the ground. Puparium yellowish brown.

On Agrostis, Arrhenatherum, Dactylis, Elymus, Festuca, Holcus and Poa, but not yet on Avena, Brachypodium or Molinia, in Britain. Widespread in Britain and continental Europe. Also Canada.

Cerodontha flavocingulata (Strobl, 1909) [Diptera: Agromyzidae].

4b > Leaf-miner: Upper surface corridor mine. The mine starts at the leaf apex. Frass in clumps or closely packed grains.

On ? Arrhenatherum in Britain and additional grasses elsewhere. British record needs confirmation. Also recorded in continental Europe.

? Liriomyza graminivora Hering, 1949 [Diptera: Agromyzidae].

4c > Leaf-miner: Larvae feed singly, forming an upper surface linear-blotch mine. Pupation either internal or external. Puparium reddish, brown or black, frequently adhering to leaf near end of mine.

Mine of Agromyza albipennis on Phalaris arundinacea
Image: Willem Ellis (Bladmineerders van Europa)

On Arrhenatherum, Brachypodium, Bromus, Dactylis, Glyceria, Holcus, Hordeum, Milium, Phalaris and Poa, but not yet on Avena or Molinia, in Britain and additional grasses elsewhere. Widespread and common in Britain. Also recorded in the Republic of Ireland. Very common in western Europe and recorded in Canada.

Agromyza albipennis Meigen, 1830 [Diptera: Agromyzidae].

4d > Leaf-miner: Larvae feed singly, forming greenish mine, initially running towards apex of leaf before turning back down and developing into a broad blotch. Puparium reddish brown.

On Arrhenatherum, Bromus, Calamagrostis, Poa, Secale and Triticum, but not yet on Avena, Brachpodium or Molinia, in Britain and additional grasses elsewhere. Widespread in Britain and continental Europe.

Agromyza rondensis Strobl, 1900 [Diptera: Agromyzidae].

5a > Leaf-miner: Normally several larvae feed together. Pupation in the mine. Puparium shining black

On Arrhenatherum, Brachypodium, Bromus, Bromopsis, Calamagrostis, Dactylis, Deschampsia, Elymus, Festuca, Holcus, Lolium, Molinia and Phalaris, but not yet on Avena, in Britain and additional grasses elsewhere. Widespread and common in Britain. Also recorded in the Republic of Ireland. Widespread and frequently common in much of Europe. Also recorded in Alaska and Canada.

Cerodontha (Poemyza) pygmaea (Meigen, 1830) [Diptera: Agromyzidae].

5b > Leaf-miner: Several larvae can occur together in a single leaf. The young larva first feeds towards the apex of the leaf, later turning and feeding downwards. Pupation external. Puparium reddish brown

Mine of Agromyza nigrociliata on Arrhenatherum elatius. Image: Willem Ellis (Source: Bladmineerders van Europa)

Mine of Agromyza nigrociliata on Arrhenatherum elatius
Image: Willem Ellis (Bladmineerders van Europa)

Agromyza nigrociliata Hendel, 1931 [Diptera: Agromyzidae].

5c > Leaf-miner: Upper-surface, unusually short corridor (ca. 4 cm). Puparium brown

On Arrhenatherum and Tragopogon and possibly Agrostis, but not yet on Avena, Brachypodium or Molinia, in Britain. Widespread but not common in southern England. Also recorded on in the Republic of Ireland and Europe.

Liriomyza pusio (Meigen, 1830) [Diptera: Agromyzidae].

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

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).

1a > Leaf-miner: The larvae feed, causing whitish mines on the blades (UKMoths). Flat, translucent mine that can either run or down; the width may vary too, can be as wide as the blade. Frass few, grey, dispersed. The larva makes several mines (Bladmineerders van Europa).

Recorded on Dactylis, Deschampsia and Holcus, but not yet on Arrhenatherum, in Britain plus Luzula, Agrostis, Alopecurus, Arrhenatherum, Avena, Avenula, Brachypodium, Bromus, Calamagrostis, Elymus, Festuca Koeleria, Phalaris, Phleum, Poa, Trisetum and Triticum elsewhere. Widespread in Britain, Ireland and continental Europe.

Elachista albifrontella (Hübner, 1817) [Lepidoptera: Elachistidae].

1b > Leaf-miner: Corridor widening while descending from the tip of the leaf. The mine is unusual because the sides are very irregularly scalloped out. Moreover, the mine is not evenly transparent, but rather yellowish green and motly, because the larva leaves patches of parenchyma uneaten, and does not feed full depth. Frass in a few irregular, interrupted length lines. Often 2-3 larvae in a mine. The larvae hibernate in the centre of the mine; after winter they leave their mine and pupate ( Bladmineerders van Europa).

Recorded on 'various grasses' in Britain plus Luzula, Agrostis, Arrhenatherum, Brahcypodium, Calamagorstis, Dactylis, Deschampsia, Elymus, Festuca, Glyceria, Holcus, Melica, Milium and Poa elsewhere. Widespread in Britain, Ireland and continental Europe.

Elachista apicipunctella Stainton, 1849 [Lepidoptera: Elachistidae].

1c > Leaf-miner: Blotch in the leaf tip; the upper side is practically flat, the lower side can turn somewhat to purple. The larva may mine 2-3 leaves (Bladmineerders van Europa).

Recorded on Avenula, but not yet on Arrhenatherum, in Britain and Arrhenatherum, Avena, Festuca, Avenula, Phleum and Poa elsewhere. Distribution in Britain unknown. Widespread in continental Europe.

Elachista bedellella (Sircom, 1848) [Lepidoptera: Elachistidae].

1d > Leaf-miner: Flat, whitish. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Holcus mollis, but not yet on Arrhenatherum, in Britain plus Agrostis, Arrhenatherum, Avenula, Deschampsia, Festuca and Poa elsewhere. Widespread in Britain and continental Europe.

Elachista canapennella (Hübner, 1813) [Lepidoptera: Elachistidae].

1e > Leaf-miner: Larva makes a large whitish blotch and mines the leaf downwards. The frass tends to be deposited in the upper part of the mine (British leafminers). Oviposition usually not far from the leaf tip. From there descends an irregular blotch mine. Hering (1957a) describes the mine as flat and quite shallow, giving it a greenish, rather than whitish appearance. Frass initially in the oldest, upper part of the mine, later in strings. The larva can leave its mine and restart elsewhere. Normally only one larva per mine, but sometimes two or even three mines in a leaf. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Dactylis, Phalaris, Phragmites and Poa, but not yet on Arrhenatherum, in Britain plus Agrostis, Alopecurus, Arrhenatherum, Brachypodium, Calamagrostis, Elymus, Festuca, Holcus, Trisetum and Triticum elsewhere. Widely distributed in Britain, Ireland and continental Europe.

Elachista maculicerusella (Bruand, 1859) [Lepidoptera: Elachistidae].

1f > Leaf-miner: The larvae feed, causing whitish mines on the blades (UKMoths). Flat, translucent mine that can either run or down; the width may vary too, can be as wide as the blade. Frass few, grey, dispersed. The larva makes several mines (Bladmineerders van Europa).

Recorded on Arrhenatherum, Festuca, Holcus and Phleum in Britain and Arrhenatherum, Festuca and Holcus elsewhere. Widespread in Britain and continental Europe. Also recorded from the Republic of Ireland.

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

1g > 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 Arrhenatherum, in Britain and Carex, Arrhenatherum, Brachypodium, Calamagrostis, Melica, Molinia and Poa elsewhere.

Elachista subalbidella Schläger, 1847 [Lepidoptera: Elachistidae].


	Last updated 03-Feb-2012 Brian Pitkin