Crepis [Asteraceae] in Leaf and stem mines of British flies and other insects

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

CREPIS. Hawks-beards. [Asteraceae]

Seventeen species of Crepis are recorded in Britain. These include the native Marsh Hawks-beard (C. paludosa), Northern Hawks-beard (C. mollis), Rough Hawks-beard (C. biennis), Smooth Hawks-beard (C. capillaris), and Stinking Hawks-beard (C. foetida) and the introduced Small-flowered Hawk's-beard (C. pulchra) and Beaked Hawk's-beard (C. vesicaria). The BSBI provide a downloadable plant crib for Crepis.

Stinking Hawks-beard (C. foetida) is protected under Schedule 8 of the Wildlife and Countryside Act, 1981.

Thirteen or fourteen British miners are recorded on Crepis.

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

Beaked Hawk's-beard
Crepis vesicaria

Key for the identification of the known mines of British
Diptera recorded on Crepis

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).

See Key to non-Diptera.

1a > Stem-miner: External stem-miner (Spencer, 1972b: 61).

On Sonchus oleraceus in Britain. On Crepis, Lapsana and Sonchus elsewhere. Uncommon, but locally abundant in Britain including London, Essex and Hunts. Widespread in continental Europe. Also recorded in Brazil, Canada, and the Afro-tropical, Australian, East Palaearctic and Oriental regions.

Phytoliriomyza arctica (Lundbeck, 1901) [Diptera: Agromyzidae].

1b > 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 Crepis, 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].

1c > Stem-miner: A narrow, inconspicuous stem mine. Pupation at the end of the mine (Spencer, 1976: 64).

Fine, upper- or lower-surface corridor, ending in a thick vein. From there the mine extends finally to the rind of the stem. There also the pupation takes place, usually not far from the root collar. Mines in the stem rind often are conspicuous through a red discoloration.

On Achillea, Achillea millefolium and possibly Anthemis, Matricaria and Medicago sativa, but not yet on Crepis, in Britain. In Britain widespread in south, not uncommon. On Anthemis, Achillea, Artemisia, Aster, Centaurea, Clinopodium, Crepis, Hieracium, Matricaria, Reichardia, Solidago, Tanacetum, Tripleurospermum, Medicago, Satureja and Stachys elsewhere. Widespread in continental Europe.

Ophiomyia curvipalpis (Zetterstedt, 1848) [Diptera: Agromyzidae].

1d > Leaf-miner

2a > Leaf-miner: A whitish blotch mine along mid-rib, often with offshoots into leaf blade.

2b > Leaf-miner: Mine linear, not along mid-rib.

3a > Leaf-miner: The larvae tunnel in the mid-rib of the basal leaves. Their presence causes the vein to swell. Pupation within the mine.

Host unknown in Britain. On Crepis biennis elsewhere. Added to the British checklist by Henshaw (2002). Recorded in continental Europe.

Phytomyza robustella Hendel, 1936 [Diptera: Agromyzidae].

3b > Leaf-miner: A whitish blotch mine along mid-rib, with offshoots into leaf blade. Pupation takes place at the base of the mid-rib (Spencer, 1972b: 25; Spencer. 1976: 63 (fig. 66)).

The mine begins as a very narrow, upper- or lower-surface corridor, somewhere in the blade. When this hits a thick vein the larva uses this to descend towards the midrib. From that moment the lave lives in the hollow midrib. From here short, lobate corridors enter the leaf blade. The larva may move to another leaf by way of the leaf base. The corridors in the leaf are virtually free of frass (at most a few grains where they leave the midrib); frass is concentrated in the base of the midrib. Here also the pupation takes place.

Mine of Ophiomyia cunctata on Taraxacum officinale. Image: © Willem Ellis (Source: Bladmineerders en plantengallen van Europa)

Mine of Ophiomyia cunctata on Taraxacum officinale
Image: © Willem Ellis (Bladmineerders van Europa)

On Crepis, Hypochaeris, Lapsana, Mycelis, Picris, Sonchus, Taraxacum and possibly Bellis in Britain and additional genera of Asteraceae elsewhere. Widespread in Britain and throughout much of Europe.

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

3c > Leaf-miner: A whitish blotch-mine along the mid-rib, with lateral offshoots into the leaf blade. Pupation at base of leaf in petiole (Spencer, 1972b: 25).

Broad corridor overlying the midrib, with short excursion into the blade, mainly in its basal part. Frass concentrated in the basal part of the mine, corridors almost free from frass. Pupation in the mine, also in the basal part.

Mine of https://bladmineerders.nl/parasites/animalia/arthropoda/insecta/diptera/brachycera/agromyzidae/agromyzinae/ophiomyia/ophiomyia-pulicaria/ on Taraxacum officinale. Image: © Willem Ellis (Source: Bladmineerders en plantengallen van Europa)

Mine of Ophiomyia pulicaria on Taraxacum officinale
Image: © Willem Ellis (Bladmineerders van Europa)

On Crepis, Hieracium, Hypochaeris, Leontodon, Picris, Pilosella, Sonchus and Taraxacum in Britain and additional genera of Asteraceae elsewhere. Widespread and common in Britain and continental Europe. Range extending east to Siberia. Also recorded from Canada.

Ophiomyia pulicaria (Meigen) [Diptera: Agromyzidae].

3d > 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 Crepis, in Britain,. Widespread throughout Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

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

4a > 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'.

Chromatomyia 'atricornis'has been recorded on Crepis in Britain.

Chromatomyia syngenesiae is recorded on Crepis elsewhere but not yet on Crepis in Britain.

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

4b > 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 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, 1823 [Diptera: Agromyzidae].

4c > Leaf-miner: A white mine along mid-rib, with offshoots into leaf blade. Pupation internal at base of mid-rib.

In Asteraceae the larva mostly lives as a borer in the midrib of the leaves. From there short corridors are made into the blade. Also a corridor can be made overlying the midrib. In Euphorbia a small mine is made in the bracts of the inflorescence. The final mine strongly resembles the one of Liriomyza strigata, but the branches are vritually free from frass; this is acccumulated in the resting place of the larva, in the base of the midrib. There also pupation takes place.

Forms a mine along the midrib and has feeding spurs into the leaf. Pupation is in the mine at the base of the midrib.

On Cicerbita, Leontodon, Sonchus and Taraxacum, but not yet on Crepis, in Britain and numerous other genera of Asteraceae elsewhere. Widespread in south, but not common, in Britain. Widespread in continental Europe.

Ophiomyia beckeri (Hendel, 1923) [Diptera: Agromyzidae].

4d > 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.

Mine of Trypeta immaculata on Taraxacum
Image: Rob Edmunds (British leafminers)

On Cichorium, Crepis, Hieracium and Taraxacum 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].

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

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 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: In the first instar the larva mines the leaves, forming short, irregular, blotch-like mines, but in later instars it lives externally, feeding in spun leaves and often twisting those of tender shoots. Larval head light-brown or yellowish brown, edged with black postero-laterally, ocellar area blackish; prothoracic plate black edged with whitish anteriorly; abdomen dull dark green; pinacula distinct, black, sometimes brownish but with black bases to setae; anal plate large, black (Bradley et al., 1973). Small, full depth mine without a definite shape; little frass. Some silk is deposited in the mine. The larva soon leaves the mine and continues feeding among spun leaves.

Polyphagous. On numerous genera and species of plant families, but not yet on Crepis, in Britain. On numerous genera and species of plant families including Crepis elsewhere. Widespread in Britain and continental Europe. Also recorded from Channel Is.

Cnephasia incertana (Treitschke, 1835) [Lepidoptera: Tortricidae].

1b > Leaf-miner: The mine begins in the midrib, especially in a lower leaf, extending into the leaf disc, branching irregularly or pinnately, may also locally be blotch like. The mine is brown and very transparent. Sides very irregularly eaten out. Frass loosely dispersed or in a loose central line, buy may also be pressed against the sides of the corridor. The larva may also leave the mine and restart elsewhere.

Polyphagous. On numerous genera and species in several plant families, but not yet on Crepis, in Britain. On numerous genera and species in several plant families, including Crepis. elsewhere. Widespread in England and continental Europe. Also recorded in the Republic of Ireland.

Orthochaetes setiger (Beck, 1817) [Coleoptera: Curculionidae].


	Last updated 03-Jul-2019 Brian Pitkin