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

1a > Stem mine: An external stem mine; frass in two rows of disconnected strips. Pupation in stem at end of mine. Puparium black

Polyphagous. On Campanula, Jasione, Phyteuma [Campanulaceae], Crepis, Hypochaeris and Lapsana [Asteraceae], but not yet on Prenanthes, 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 [Diptera: Agromyzidae].

1b > 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 Prenanthes, in Britain. Widespread throughout Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

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

1c > Leaf-miner: A whitish blotch-mine along mid-rib, with offshoots into leaf blade. Pupation takes place at the base of the mid-rib. Puparium yellowish white

On Crepis, Hypochaeris, Lapsana, Mycelis, Picris, Sonchus, Taraxacum and possibly Bellis, but not yet on Prenanthes, in Britain and additional genera of Asteraceae elsewhere. Widespread in Britain and throughout much of Europe.

Ophiomyia cunctata (Hendel, 1920) [Diptera: Agromyzidae].

1d > Leaf-miner: Larva mining both lower and upper surface, unusually long, linear, conspicuously broad, frequently largely on the underside of the leaf. Pupation external (Spencer, 1972b: 76 (fig. 251); Spencer, 1976: 445 (fig. 780), 446).

Corridor mine. The first part consists of a very long and narrow lower-surface corridor; the mine is quite shollow here, and often inconspicuous. The second part is upper-surface, uusally much shorter, and widens abruptly. Pupation outside the mine.

On Crepis, Hieracium, Lapsana, Picris, Pilosella, Senecio, Sonchus and Taraxacum, but not yet on Prenanthes, in Britain and additionally other genera of Asteraceae elsewhere. Widespread in southern Britain, also Sutherland, Inner Hebrides and Warwick. Also recorded in the Republic of Ireland and Widespread in much of Europe.

Phytomyza marginella Fallén, 1923 [Diptera: Agromyzidae].

1e > Leaf-miner: A small primary blotch, often several larvae feeding together (Spencer, 1972b: 56 (fig. 186); Spencer, 1976: 270, 271 (fig. 483)).

Brown, upper-surfsce blotch; often several larvae in a mine. The blotch is preceded by a short initial corridor, often overrun by the later blotch. Frass in a few, small grains. Secondary feeding lines well visible. Pupation outside the mine, exit slit in upper epidermis.

Small upper surface blotch, with occasional galleries leading from the blotch. Often several larvae feeding together.

On Sonchus arvensis, Sonchus asper, Sonchus oleraceus and Sonchus palustris, but not yet on Prenathes, in Britain. On Cichorium, Lactuca, Mycelis, Prenanthes and Sonchus elsewhere. Widespread, at least in south, in Britain. Widespread and common in much of Europe. Also recorded in Canada.

Liriomyza sonchi Hendel, 1931 [Diptera: Agromyzidae].

1f > Leaf-miner: The mine begins with a very narrow full depth corridor, that ends upon the midrib. Subsequently a broad corridor, or rather an elongated blotch, is made overlying the midrib; from here broad, lobe-like extensions are made into the blade. Frass in discrete grains. Secondary feeding lines conspicuous. The larva is capable of leaving the mine and restarting in a new leaf, in which case the association with the midrib may be lost. Pupation after vacation of the mine.

On Cichorium, Crepis, Hieracium and Taraxacum, but not yet on Prenanthes, in Britain and additionally other genera of Asteraceae elsewhere. North-east Scotland, also throughout Ireland and continental Europe, except the Mediterranean area.

Trypeta immaculata (Macquart, 1835) [Diptera: Tephritidae].