|
CYNOGLOSSUM. Hound's-toungues. [Boraginaceae] |
|
|
Five species of Cynoglossum are recorded in Britain. These include the native Green Hound's-tongue (C. germanicum) and Hound's-tongue (C. officinale). Green Hound's-tongue (C. germanicum) is protected under Schedule 8 of the Wildlife and Countryside Act, 1981. Only one Diptera miner, the agromyzid Agromyza abiens, is recorded on Cynoglossum in Britain and this is also recorded on Borago, Echium, Myosotis, Pentaglottis, Pulmonaria, and Symphytum in Britain. Elsewhere the agromyzids Agromyza abiens, Agromyza myosotidis and Chromatomyia horticola are recorded mining Cynoglossum.
|
|
|
No non-Diptera miners are recorded on Cynoglossum in Britain. Elsewhere one British non-Diptera miner, Coleophora pennella, is recorded on Cynoglossum (see below). A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Cynoglossum is provided in Bladmineerders van Europa. This includes Agromyza abiens, Agromyza myosotidis, Chromatomyia horticola, Apterona helicoidella, Cnephasia asseclana, Coleophora pennella, Dialectica scalariella. |
|
|
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: A narrow linear leaf mine, which developes into a large blotch. Several larvae frequently feed together and the resulting mine can entirely fill the leaf. Puparium reddish brown
Agromyza abiens Zetterstedt, 1848 [Diptera: Agromyzidae]. |
|
Key for the identification of British non-Diptera mines recorded on
|
|
|
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 and case-bearer: The larva feeds in a distinctive case made from hairy leaf fragments of the foodplant (UKMoths). The young larva feeds on the developing seeds and hibernates in its first case which is made of the tip of a petal. After hibernation it makes a hoary, laterally flattened composite leaf case (resembling a willow catkin). Full depth mines are made at the margin of the leaves, that thereby look peculiarly damaged. Mouth angle 70° (Bladmineerders van Europa). Initially forms a blotch mine, in the centre of a leaf, which it excises for its initial case. In the spring it repeatedly extends its case and it resembles a jagged catkin of willow. The larva may wander from its foodplant and attach to other plants or fences etc (British leafminers).
Coleophora pennella (Denis and Schiffermüller, 1775) [Lepidoptera: Coleophoridae] |
| Last updated 31-Jan-2012 Brian Pitkin |  |
|