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(Coleoptera, Diptera, Hymenoptera and Lepidoptera)
by
Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds
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IVA.
Marsh-elder. [Asteraceae]
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Three
species of Iva are recorded in Britain. All, including Marsh-elder
(I. xanthiifolia), are introduced.
Two British miners are recorded on Iva.
A key to the European miners recorded on Iva is provided in Bladmineerders van Europa.
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Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Iva
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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. A long whitish upper surface corridor, which eventually goes lower surface. |
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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'.
Chromatomiya 'atricornis' is tentatively recorded on Iva in Britain.
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Chromatomyia
horticola (Goureau, 1851) [Diptera: Agromyzidae]
OR
Chromatomyia
syngenesiae Hardy, 1849 [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. |
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Polyphagous. On more than 40 host genera in 15 families in Britain including Iva. Widespread
throughout Britain. Also recorded in the Republic of Ireland.
Widespread in continental Europe.
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Liriomyza strigata (Meigen, 1830) [Diptera: Agromyzidae]. |
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