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(Coleoptera, Diptera, Hymenoptera and Lepidoptera)
by
Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds
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FORSYTHIA.
Golden-bell and Forsythia. [Oleaceae]
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One
species snd one hybrid of Forsythia are recorded in Britain.
Two British
miners are recorded on Forsythia.
A key to the European miners recorded on Forsythia is provided in Bladmineerders van Europa. |
Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Forsythia
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1a > Leaf-miner
and case-bearer: The larva feeds by inserting its head into small
mines it creates on the leaves of birch, elm, alder, or hazel. Occasionally
it is found feeding on other trees, or on herbaceous plants onto
which it has accidentally Fallén. It forms two cases during its
larval life. The first case is initially curved, smooth, laterally
compressed with a bivalved anal opening, and about 2 mm long in
September. During October it feeds, and adds a few rough collars
of larval material around the oral opening. After hibernation, it
feeds again in April and early May, adding more protruding collars
until they equal or exceed the original smooth part of the case.
At the same time, it expands the case girth by the creation of a
silk gusset ventrally. The second case, 6 or 7 mm long, is formed
in May, leaving the vacated first case attached to its last feeding
mine. The new case is tubular with a trivalved crimp at the anal
opening. The dorsum is formed from the edge of the leaf from which
the case was cut. This results in a more or less serrated dorsal
keel, depending on the plant species and the individual piece of
leaf used. Considerable variation in the degree of serration can
be found, even among specimens off the same tree. The case colour
varies with food plant, from yellowish brown on birch, darkening
through elm and hazel to dark brown on alder.
The strongly curved young case is is a composite leaf case, the
adult case is a tubular leaf case. The adult case is bivalved, about
7 mm in length; the mouth angle is around 30°. The case is straw
coloured and almost always has a toothed dorsal keel (remnant of
the margin of the leaf from which the case was cut). Neither larvae
or cases of C.
coracipennella, prunifoliae, serratella and spinella can be
separated; from serratella. |
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On Alnus, Betula, Corylus, Ulmus and Sorbus but
not yet on Forsythia, in Britain plus Carpinus,
Mespilus, Ostrya, Hippophae, Ribes, Myrica, Forsythia, Amelanchier,
Chaenomeles, Cotoneaster, Crataegus, Cydonia, Eriobotrya, Malus,
Prunus, Sorbus,
Spiraea, Populus and Salix elsewhere. This is probably the commonest species of British
coleophorid, and is found throughout the British Isles. Widespread
in continental Europe.
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Coleophora
serratella (Linnaeus 1761) [Lepidoptera: Coleophoridae]. |
1b > Leaf-miner, but not a case-bearer: Larvae usually gregarious.
Early mine an epidermal gallery leading to a contorted blotch with
black frass. Subsequently two successive cones formed by folding
the tip of a leaf downwards (British
leafminers, as Caloptilia syringella). Often, many leaves
on a single bush turn brown and curl up with the mines. The species
can be a pest in gardens.
The mine begins at a row of eggs along the midrib. The emerging
larvae form relatively broad, inconspicuous, lower-surface corridor.
Subsequently a large, grey brown or greenish brown, very opaque
upper-surface blotch is made, occupied by ten or more larvae. The
mine makes the leaf somewhat bumpy, but the leaf does not fold around
the mine, like in Caloptilia
cuculipennella. After some time the larvae leave the mine
and continue feeding, still comunnally, in a downwards rolled leaf. |
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Gracillaria syringella larva
Image: © Willem Ellis (Bladmineerders van Europa) |
On Symphoricarpos, Fraxinus, Jasminum, Ligustrum, Phillyrea and Syringa, but not yet on Forsythia, in
Britain and Chionanthus, Forestiera, Forsythia, Fraxinus, Jasminum,
Ligustrum, Phillyrea and Syringa elsewhere. Widespread
in Britain, Ireland and continental Europe.
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Gracillaria
syringella (Fabricius, 1794) [Lepidoptera: Gracillariidae]. |
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