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


TRAGOPOGON. Goat's-beard and Salsifies. [Asteraceae]

Four species of Tragopogon are recorded in Britain. These include the native Goat's-beard (T. pratensis) and the introduced Slender Salsify (T. hybridus) and Salsify (T. porrifolius). The BSBI provide a downloadable plant crib for subspecies of Tragopogon pratensis.

Five british miners are recorded on Tragopogon.

The polyphagous agromyzid Liriomyza trifolii has been recorded in quarantine in Britain (Pitkin & Plant in British leafminers). See also Liriomyza species in Glasshouses and/or Quarantine Interceptions.

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

Goat's-beard - Tragopogon pratensis. Image: © Brian Pitkin
Tragopogon pratensis

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

1a > Stem miner: An external stem mine with frass in two rows of disconnected strips. Pupation in stem at end of mine (Spencer, 1972b: 25; Spencer, 1976: 61 (fig. 63B), 65-6).

Polyphagous. On Campanula, Jasione, Phyteuma [Campanulaceae], Crepis, Hypochaeris and Lapsana [Asteraceae], but not yet on Tragopogon, in Britain and additional genera of both families elsewhere. Uncommon in Britain - recorded in London, Warwick and Cambridge. Uncommon but Widespread in continental Europe.

Ophiomyia heringi Stary, 1930 [Diptera: Agromyzidae].

1b > Leaf-miner


2a> Leaf-miner: Green, later brownish corridor or more often an elongated whitish linear blotch overlying the midrib. The mine has short, irregular side branches. Frass in irrgular, dispsersed grains. Pupation outside the mine.

On Tragopogon porrifolius and Tragopogon pratensis in Britain and elsewhere. Widespread in Britain and elsewhere.

Liriomyza tragopogonis (Meijere, 1928) [Diptera: Agromyzidae].

2b > Leaf-miner: Upper-surface, unusually short corridor (ca. 4 cm). Sometimes several mines in a leaf. Pupation outside the mine.

On Arrhenatherum and ? Tragopogon and possibly Agrostis in Britain and Arrhenatherum elsewhere. Widespread but not common in southern England. Also recorded on in the Republic of Ireland and continental Europe.

Liriomyza pusio (Meigen, 1830) [Diptera: Agromyzidae].

2c > Leaf-miner: A distinctive mine primarily above mid-rib, with irregular short lateral offshoots into leaf blade. Pupation external (Spencer, 1972: 51 (fig. 172), 55; Spencer, 1976: 270, 271 (fig. 486)).

Branched, whitish, upper-surface corridor; main axis overlying the midrib; side branches overlying the main lateral veins. (In Campanula and Phyteuma the mine is much less branched, sometimes nothing more than a corridor on top of the midrib). Frass in rather long strings. Usually the mines begins as a long and narrow, shallow, tortuous lower-surface corridor that ends upon the midrib but otherwise is not associated with the leaf venation. Often this initial corridor is filled with callus, and then even less conspicuous. Pupation outside the mine.

A linear mine on the upper surface, usually following the midrib and showing side branches along the veins. The frass is in strings.

Polyphagous. On more than 40 host genera in 15 families, but not yet on Tragopogon, in Britain. Widespread throughout Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Liriomyza strigata (Meigen, 1830) [Diptera: Agromyzidae].

2d > Leaf-miner: 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'.

Chromatomiya 'atricornis' is tentatively recorded on Iva elsewhere but not yet on Tragopogon in Britain.

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

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