CARLINA. Carline Thistles [Asteraceae]

Two species of Carlina are recorded in Britain, including the native Carline Thistle (C. vulgaris).

The British anthomyiid Pegomya steini is recorded on Carlina by Ackland in Chandler (1978), but it is not clear whether the host association is British or Foreign.

Elsewhere the agromyzid Chromatomyia 'atricornis' and the anthomyiid Pegomya steini are recorded mining Carlina.

No non-Diptera miners are recorded on Carlina in Britain.

Elsewhere two British non-Diptera miners are recorded on Carlina, although one of these is probably incidental (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Carlina is provided in Bladmineerders van Europa. This includes Coleophora peribenanderi, Agonopterix nanatella, Agonopterix arenella, Agonopterix nanatella, Chromatomyia 'atricornis' and Orthochaetes insignis but not Coleophora paripennella; Scrobipalpa acuminatella, Tebenna micalis or Pegomya steini.

Carline Thistle
Carlina vulgaris

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).

1a > Leaf-miner: Long narrow interparenchymal mine, greenish. Pupation in leaf at end of mine. Puparium white

Mines of Phytomyza spinaciae on Cirsium arvense Image: Willem Ellis (Bladmineerders van Europa)

On Carduus, Centaurea, Cirsium and Onopordum in Britain and in addition Cnicus and Serratula elsewhere. Only recorded from Warwick and Stafford in Britain. Also recorded in the Repupublic of Ireland. Widespread in continental Europe, range extending to the Kirghiz Republic of the [former] U.S.S.R.

Phytomyza spinaciae Hendel, 1928 [Diptera: Agromyzidae].

1b > Leaf-miner: Larva feeds along the mid-rib, predominantly on the lower surface and there is little evidence of gall-like swelling. Pupation takes place at the base of the midrib.

On Carduus and Centaurea in Britain. On Arctium, Carduus, Cichorium and Cirsium elsewhere. Widespread in Britain and continental Europe.

Phytomyza continua Hendel, 1920 [Diptera: Agromyzidae].

1c > Leaf-miner: Large, very transparent blotch, with primary and secundary feeding lines. In the centre a concentration of black frass. Mines can coalesce, and then contain several larvae. At the start of the mine, at the leaf underside, a white egg shell. However, the larva can leave its mine and restart elsewehere, therefore mines without an egg shell may occur as well

Mine of Pegomya steini on Cirsium vulgare Image: Willem Ellis (Bladmineerders van Europa)

On Carduus, Carlina, Cirsium and Cynara in Britain and elsewhere, although British records on Carduus and Carlina are ambiguous. Distibution in Britain unknown. Widespread in continental Europe.

Pegomya steini Hendel, 1925 [Diptera: Anthomyiidae].

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

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 and case-bearer: The larva forms a case, approximately 11-12 mm long, beneath a thistle leaf, although burdock may sometimes be used. The shape of the ochreous case varies as, when being enlarged, it is elongated first, and the girth increased subsequently (UKMoths). Yellow-brown to light grey tubular silken case with darker length lines. The case is fairly large (up to 17 mm) and very slender. The rear end is three-valved, the mouth angle about 50°. The larva feeds at the underside of the leaf (Bladmineerders van Europa).

Recorded on Arctium, Carduus and Cirsium, but not yet on Carlina, in Britain and Arctium, Carduus, Carlina, Centaurea and Cirsium elsewhere. England, Wales and southern Scotland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Coleophora peribenanderi Toll, 1943 [Lepidoptera: Coleophoridae]

1b > Leaf-miner, but not a case bearer: The mine is brownish and extends along the midrib, sometimes branching (British leafminers).

Oviposition on top of the midrib. Immediately after emergence the larva gnaws a cavity in the midrib, and from there an irregular blotch is made adjacent to the midrib. The larva continues living in the midrib that is gradully hollowed out, making from there broad, brownish, full depth excursions in the blade. The mine contains much frass; most of it is concentrated in the area immediately bordering the midrib. Older, no longer occupied parts of the mine often split open. Mines mainly on the lower leaves. The slender larvae move surprisingly fast upon disturbance; when they rest (in daytime) they lie lengthwise in the hollowed midrib. Pupation outside the mine (Bladmineerders van Europa).

Recorded on Artemisia, Carduus, Cirsium and possibly Tussilago, but not yet on Carlina, in Britain and Carduus and Cirsium elsewhere. Records from Carlina vulgaris and Tussilago farfara are probably incidental. Widespread in Britain and continental Europe.

Scrobipalpa acuminatella (Sircom, 1850) [Lepidoptera: Incurvariidae]