The leaf and stem mines of British flies and other insects
 

(Coleoptera, Diptera, Hymenoptera and Lepidoptera)

by Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds

 

CARLINA. Carline Thistles [Asteraceae]


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

Five British miners are recorded on Carlina.

A key to the European miners recorded on Carlina is provided in Bladmineerders van Europa.

Carline Thistle - Carlina vulgaris. Image: © Brian Pitkin
Carline Thistle
Carlina vulgaris



Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Carlina


1a > Leaf-miner and case-bearer: The larva lives outside the mine, protected by a case, and feeds on the underlying plant tissues via a hole cut in the epidermis. From that point it eats away as much leaf tissue as it can reach without fully entering the mine. Mine does not contain frass (Coleophora species). 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. 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.

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.

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.

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].

1c >Leaf-miner, but not a case-bearer: Mine linear, whitish, both upper and lower surface. Pupation internal, at the end of the mine with the anterior spiracles projecting through the epidermis (Spencer, 1976: 433).

Upper-surface, less often lower-surface corridor. Frass in isolated grains. Pupation within the mine, usually in a lower-surface puparial chamber.

A long whitish upper surface corridor, which eventually goes lower surface.

Two highly polyphagous species of Chromatomyia, with indistinguishable mines, have been recorded in Britain. These are syngenesiae (Hardy) and horticola (Goureau) which can only be distinguished by the male genitalia. Both species are widespread in Britain and elsewhere, although syngenesiae is almost entirely restricted to Asteraceae. Records on Asteraceae not based on examination of male genitalia are treated in this account as Chromatomyia 'atricornis'.

Chromatomyia 'atricornis' has been recorded on Carlina elsewhere, but not yet on Carlina, in Britain.

Chromatomyia horticola (Goureau, 1851) [Diptera: Agromyzidae]
OR
Chromatomyia syngenesiae Hardy, 1849 [Diptera: Agromyzidae].

1d > Leaf-miner, but not a case-bearer: 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.

A white egg is laid at the start of the mine, on the leaf underside. A large clear mine is formed in the centre of the leaf, with a black frass pile. Mines may coalesce and so a mine may contain several larvae (British Leafminers).

Mine of Pegomya steini on Cirsium vulgare. Image: © Willem Ellis (Source: Bladmineerders en plantengallen van Europa)
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].

1e >Leaf-miner, but not a case-bearer:Rather narrow corridor, untidy and sometimes branched, starting from the base of the leaf, in particular the midrib. Sides of the corridor irregularly eaten out, not really parallel. Frass mostly present, and then in a central line. The larva is capable of leaving the mine and start a new one elsewhere. These later mines are much broader, and the frass is scattered irregularly..

Mine of Orthochaetes insignis on Prunella vulgaris
Mine of Orthochaetes insignis on Prunella vulgaris
Image: © Jean-Yves Baugnée (Bladmineerders van Europa)

Host plants unknown in Britain. On numerous genera and species in several plant families, including Carduus, elsewhere. Recorded in southern England. Widespread in continental Europe.

Orthochaetes insignis (Aube, 1863) [Coleoptera: Curculionidae].



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