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).

# > Details of mine unknown.

On Solidago in Britain. On Anaphalis, Arnica, Aster, Erigeron, Petasites and Solidago elsewhere. Only known from Aberdeen in Britain. Only known from Sweden and possibly Germany in continental Europe.

Pegomya depressiventris (Zetterstedt, 1845) [Diptera: Anthomyiidae]

1a > 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 (Bladmineerders van Europa). A linear mine on the upper surface, usually following the midrib and showing side branches along the veins. The frass is in strings (British leafminers).

On more than 40 host genera in 15 families in Britain includng Solidago. Widespread throughout Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

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

1b > Mine not primarily associated with the mid-rib.

2

2a > A linear mine commencing with a conspicuous regular spiral and then continuing a considerable distance more or less straight.

On Aster, Eupatorium, Helianthus, Lapsana and Solidago [Asteraceae] and Galeopsis [Lamiaceae] in Britain and continental Europe. Widespread in England. Also recorded in the Republic of Ireland. Widespread in continental Europe and recorded in Canada.

Liriomyza eupatorii (Kaltenbach, 1873) [Diptera: Agromyzidae].

2b > An irregular linear mine, which in small leaves can form a secondary blotch. Puparium orange

On Aster, Bellis and Solidago in Britain and additional genera of Asteraceae elsewhere. Widespread in Britain. Also recorded in the Republic of Ireland. Widespread and common in much of continental Europe.

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

2c > Broad corridor overlying the midrib. The mine has a number of side branches that distally widen strongly, and may coalesce. Primary and secondary feeding lines very conspicuous. Puparium yellow. Pupation external, in soil.

Mine of Cornutrypeta spinifrons on Senecio ovalis Image: Willem Ellis (Bladmineerders van Europa)

On Aster and Solidago in Britain in Britain and possibly also Cirsium elsewhere. In Britain Recently recorded only from Kent and Perth. There are old records (pre-1960) for Hereford and Lancaster.

Cornutrypeta spinifrons (Schroeder, 1913) [Diptera: Tephritidae].

2d > A large, brownish blotch, with conspicuous feeding lines. Pupation external. Puparium reddish brown

On Solidago canadensis and Solidago virgaurea in Britain. On Aster, Baccharis, Buphthalum, Erectites and Soligago elsewhere.

Nemorimyza posticata (Meigen, 1830) [Diptera: Agromyzidae].

2e > A long, winding leaf-mine on the upper surface of the leaf, with frass widely-spaced in conspicuous black lumps. Pupation internal, at the end of mine. Puparium black or whitish-grey

On Solidago in Britain. On Aster, Callistephus, Erigeron, Sonchus, Solidago and Taraxacum elsewhere. Only recorded from Kent, Derby, Warwick and East Kent in Britain. Widespread in much of Europe. Also recorded in Japan, Canada and the U.S.A.

Ophiomyia maura (Meigen, 1838) [Diptera: Agromyzidae].

2f > A conspicuous white mine with frass in more or less connected strips, older mines can show a conspicuous reddish-violet discolouration. Puparium black.

Mine of Phytomyza solidaginis on Solidago virgaurea Image: Willem Ellis (Bladmineerders van Europa)

On Solidago virgaurea in Britain and elsewhere. Probably widespread in Britain. Widespread in continental Europe.

Phytomyza solidaginis Hendel, 1920 [Diptera: Agromyzidae].

2g > A whitish linear mine, with frass predominantly in separate grains, rather than connected strips. Puparium black

On Solidago virgaurea in Britain and elsewhere. Also on Bellis perennis elsewhere. Only known from Surrey in Britain. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Phytomyza virgaureae Hering, 1826 [Diptera: Agromyzidae].

2h > The pale-coloured mine runs on the upper side irregularly to the sides, in the middle with blackish spots, where the frass is deposited. It starts in the center of a leaf and without a small mine leading to a large mine. Many mines in a leaf could finally cover the whole leaf

Mine of Pegomya nigrisquama Image: Rob Edmunds (British leafminers)

On Aster and Solidago in Britain and elsewhere. Rarely found in the the UK. Recorded from Somerset, Oxford, Suffolk and Cambridge and West Kent. Also recorded in continental Europe.

Pegomya nigrisquama (Stein, 1888) [Diptera: Anthomyiidae].