LUZULA. Wood-rushes. [Juncaceae]

Ten species of Luzula are recorded in Britain. These include the native Curved Wood-rush (L. arcuata), Field Wood-rush (L. campestris), Southern Wood-rush (L. forsteri), Heath Wood-rush (L. multiflora), Fen Wood-rush (L. pallidula), Hairy Wood-rush (L. pilosa), Spiked Wood-rush (L. spicata) and Great Wood-rush (L. sylvatica) and the introduced White Wood-rush (L. luzuloides) and Snow-white Wood-rush (L. nivea).

Four Diptera miners, the agromyzids Cerodontha bimaculata, Cerodontha luzulae, Cerodontha silvatica and Chromatomyia luzulae, are recorded on Luzula in Britain.

Elsewhere the agromyzids Cerodontha luzulae and Cerodontha silvatica are recorded mining Luzula.

Four non-Diptera miners are recorded on Luzula in Britain (see below).

Elsewhere two additional British non-Diptera miners are recorded on Luzula (see below).

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

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 Luzula, 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', but not yet on Luzula, 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].

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].

1d > Leaf-miner: The mine formed is long, inflated and puckers the leaf surface. The larva often swaps leaves (British leafminers). Oviposition generally at the underside of the top half of the leaf. Between September and the end of February a very narrow mine is made, not longer than 3 cm, parallel to the midrib. The mine then suddenly widens to almost the full width of the leaf. The frass is concentrated in the transition area of the two mine types. In the broad part folds develop. Larvae can make a new mine, obviously without the initial part. Here the frass in concentrated around the entrance hole. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Luzula in Britain and elsewhere. Occurs in South West England, from Monmouth in Wales and the East of Scotland. Romania, Germany and The Netherlands.

 

Elachista regificella Sircom, 1849 [Lepidoptera: Elachistidae].

1e > Leaf-miner: A strongly contracted upper-surface tentiform mine, generally in the lower third of the leaf, beginning at the leaf base. Often a second or third mine is made, starting from the leaf tip. These secondary mines begin as a narrow, almost completely frass-filled corridor, that continues down to the leaf base.al the while widening into a tentiform mine. Pupation outside the mine (Steuer, 1980a) (Bladmineerders van Europa).

Recorded on Luzula in Britain and elsewhere. Widespread in Britain and continental Europe.

 

Elachista tengstromi Kalia, Bengstsson, Sulcs and Junnilainen, 2001 [Lepidoptera: Elachistidae].

1f > Leaf-miner: The mine in Luzula pilosa is rarely at the leaf-tip, being usually about halfway down the leaf blade and well clear of the winter/pring dieback. The autumn mine typically consists of a long stright slended gallery folloowing one of the veims. The mine is no wider than the larva and the frass is scattered towards or away from the leaf-tip. In spring the mine is contined as a broad elongated gallery with frass irregularly placed. Pupation occurs on the upper surface of a leaf and is anchored by a silk girdle (Bland and Knill-Jones, 1988). From autumn until early spring the larva makes a quite narrow corridor with a total length of 12-16 cm, essentually running parallel to the leaf venation; the corridor may change direction 2-3 times. Generally the corridor lies about halfway the length of the leaf. In March-April this gallery abruptly gives way to an elongate blotch, that generally obliterates the original gallery. The larva may leave its mine and restart elsewhere by making a lower-surface opening in a new leaf, not far from the leaf-tip. Pupation external (Bladmineerders van Europa).

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