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ANTHOXANTHUM. Sweet Vernal-grass. [Poaceae] |
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Three species of Anthoxanthum are recorded in Britain. These include the native Sweet Vernal-grass (A. odoratum). Only one Diptera miner, the agromyzid Chromatomyia nigra, is recorded on Anthoxanthum in Britain. Miners on grasses should be reared, whenever possible, to confirm their identity. Elsewhere the grass-feeding agromyzids Cerodontha incisa and Chromatomyia nigra are recorded mining Anthoxanthum. Two non-Diptera mines, Cosmopterix orichalcea and Elachista humilis are recorded on Anthoxanthum in Britain (see below). The coleophorid Coleophora lixella is recorded as a seed-feeder on Anthoxanthum in Britain. A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Anthoxanthum is provided in Bladmineerders van Europa. This includes Coleophora lixella, Cosmopterix orichalcea, Elachista dimicatella, Elachista humilis, Liriomyza flaveola, and Cerodontha incisa but not Chromatomyia fuscula. |
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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: Long, narrow, whitish mine. Pupation internal. Puparium yellowish brown, anterior spiracles projecting through the epidermis.
Chromatomyia nigra (Meigen, 1830) [Diptera: Agromyzidae]. |
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Key for the identification of British
non-Diptera leaf-miners on
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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).
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1a > Leaf-miner: Makes long narrow galleries. The frass is distributed through the mine and also some is ejected. The larvae may mine more than one leaf (British leafminers). Elongate, rather irregular blotch. Most frass is ejected, what remains is concentrated in a few heaps. The larva makes several mines. Pupaton outside the mine (Bladmineerders van Europa).
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Cosmopterix orichalcea Stainton, 1861 [Lepidoptera: Cosmopterigidae].
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1b > 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).
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Elachista humilis Zeller, 1850 [Lepidoptera: Elachistidae].
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| Last updated 03-Feb-2012 Brian Pitkin |  |
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