Avenula [Poaceae]

AVENULA. [Poaceae]

Seven species of Avenula are recorded in Britain.

One Diptera miner, Chromatomyia nigra, is recorded on Avenula in Britain.

Elsewhere the agromyzids Agromyza mobilis , Agromyza nigrella , Agromyza nigrociliata, Cerodontha pygmaea , Chromatomyia nigra and Liriomyza flaveola and the ephydrid Hydrellia griseola are recorded mining Avenula.

Two non-Diptera mines, Elachista bedellella and Elachista subnigrella, are recorded on Avenula in Britain (see below).

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

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Avenula is provided in Bladmineerders van Europa. This includes Agromyza mobilis, Agromyza nigrella, Chromatomyia nigra, Cerodontha pygmaea, Hydrellia griseola, Liriomyza flaveola, Hispa atra, Elachista albifrontella, Elachista argentella, Elachista bedellella, Elachista canapennella, Elachista pullicomella, Elachista subnigrella and Elachista unifasciella.

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 Avenula or 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
Avenula

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 larva mines from the grass tip downwards and the mine occupies half or the whole of the leaf blade width. A whitish blotch is formed with characteristic narrow streaks of frass (British leafminers). Full depth blotch, slightly inflated, descending from the leaf tip, occupying half or the entire width of the blade. The larva may move and make a new mine elsewhere. In the latter case the mines are fairly short; otherwise an entire blade may be mined out. Frass in a some narrow greyish brown streaks. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Dactylis, Deschampsia and Holcus, but not yet on Avenula, 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: In autumn the larva makes a narrow corridor a few cm in length, in which it hibernates. In March it moves to a new leaf. Here a transparent, full depth mine is made that descends from the leaf tip, and occupies the entire width of the blade. Most frass is concentrated in the oldest, highest, part of the mine. The larva may leave its mine and restart elsewhere. Pupation outside the mine

Mine of Elachista argentella on Dactylis glomerata
Image: Ben Smart (British leafminers)

Recorded on Dactylis glomerata, but not yet on Avenula, in Britain. Recorded on numerous grasses including Avenula elsewhere. Widespread in Britain and continental Europe. Also recorded in the Republic of Ireland.

Elachista argentella (Clerck, 1759) [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 pratense in Britain and Arrhenatherum, Avena, Festuca, Avenula, Phleum and Poa elsewhere. Distibution in Britain uknown. 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, but not yet on Avenula, in Britain and Agrostis, Arrhenatherum, Deschampsia, Festuca, Avenula, Holcus and Poa elsewhere. Britain and Northern Ireland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

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

1e > Leaf-miner: Narrow, flat, corridor descending from the leaf tip. Frass in an almost continuous line. The larva usually makes several mines. Mines pale yellow green at first, turning purple later. Pupation external (Bladmineerders van Europa).

Recorded on Bromopsis erecta and Avenula pubescens in Britain and Avena, Bromopsis, Calamagrostis, Dactylis, Festuca, Avenula and Holcus elsewhere. Southern England. Widespread in continental Europe.

Elachista subnigrella Douglas, 1853 [Lepidoptera: Elachistidae].

1f > Leaf-miner: In autumn the larva makes a long, somewhat blistered, slightly transparent corridor. In spring it mines the basal leaves that lie on the ground. These mines are swollen, clouded green, opaque, and the mined tips of the leaves are puckered and shrunken, filled with frass (Bladmineerders van Europa).

Recorded on Brachypodium and Dactylis, but not yet on Avenula, in Britain and Brachypodium, Dactylis, Avenula, Holcus and Milium elsewhere. Recorded from North Essex, North Hants and South Essex in Britain. Widespread in continental Europe.

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


	Last updated 04-Feb-2012 Brian Pitkin