1a > 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, in a, usually lower-surface, pupal chamber (Bladmineerders van Europa). A long whitish upper surface corridor, which eventually goes lower surface (British leafminers).

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 are polyphagous and widespread in Britain and elsewhere, although syngenesiae is almost entirely restricted to Asteraceae (see also 'atricornis').

Chromatomyia horticola is recorded on 55 plant genera in 19 families, but not yet on Ageratum, in Britain.

Chromatomyia syngenesiae is recorded in Britain on 27 plant genera in the family Asteraceae and many more genera elsewhere, but not yet on Ageratum, in Britain.

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

1b > Leaf-miner: A tightly coiled, almost blotch-like mine.

A polyphagous pest of ornamental and vegetable crops occasionally intercepted at UK points of entry. Hosts cited here include 155 plant genera in 41 plant families worldwide and include Ageratum elsewhere.

The species has been found under glass in England and Wales, but not yet on Ageratum. All populations have been and continue to be eradicated (Dom Collins, pers. comm.).

Liriomyza trifolii is listed in the European Community Plant Health Directive (2000/29/EC). As a non-native notifiable pest species, its occurence in the United Kingdom should be notified immediately to the Plant Health and Seeds Inspectorate (tel: +44 (0) 1904 462000, e-mail: info@fera.gsi.gov.uk ) However, in order to be certain of the identity, the male genitalia should be critically examined. Diagnostic protocols may be found at /protocols/liriomyza.pdf

 

Liriomyza trifolii (Burgess, 1880) [Diptera: Agromyzidae].

1c > 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).

A polyphagous species recorded here from 240 host plant genera in 35 plant families worldwide and 47 host plant genera in 15 plant families, but not yet on Ageratum, in Britain.

 

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

1d > Leaf-miner: An irregular serpentine mine, indistinguishable from mine of Liriomyza bryoniae. Corridor, freely winding through the leaf. Frass in strings. Pupation outside the mine (Bladmineerders van Europa).

A highly polyphagous pest of ornamental and vegetable crops occasionally intercepted on produce at UK points of entry. It cannot survive cold areas except in glasshouses. Hosts cited here include 134 plant genera in 33 plant families worldwide, but not yet on Ageratum in Britain

Liriomyza sativae is listed in the European Community Plant Health Directive (2000/29/EC). As a non-native notifiable pest species, its occurence in the United Kingdom should be notified immediately to the Plant Health and Seeds Inspectorate (tel: +44 (0) 1904 462000, e-mail: info@fera.gsi.gov.uk ) However, in order to be certain of the identity, the male genitalia should be critically examined. Diagnostic protocols may be found at /protocols/liriomyza.pdf - See also Collins (1996).