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).

Two Diptera miners, the agromyzids Liriomyza pusio and Liriomyza tragopogonis, are recorded on Tragopogon in Britain.

The polyphagous agromyzid Liriomyza trifolii has been recorded in quarantine in Britain (Pitkin and Plant in British leafminers).

Elsewhere the agromyzids Chromatomyia 'atricornis', Liriomyza strigata, Liriomyza trifolii and Ophiomyia heringi are recorded on Tragopogon.

No British non-Diptera miners are recorded on Tragopogon.

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




Key for the identification of the mines of British Diptera recorded on
Tragopogon




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 > 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, dispersed grains. Pupation outside the mine. Puparium orange

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

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

1b > Upper-surface, unusually short corridor (ca. 4 cm). Puparium brown

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

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



Valid HTML 4.01 Transitional
Last updated 02-Feb-2012  Brian Pitkin Top of page