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MYOSOTIS.
Forget-me-nots. [Boraginaceae]
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Thirteeen
species of Myosotis are recorded in Britain. These include
the native Field Forget-me-not (M. arvensis), Changing Forget-me-not
(M. discolor), Early Forget-me-not (M. ramosissima),
Jersey Forget-me-not (M. sicula), Tufted Forget-me-not (M.
laxa), Water Forget-me-not (M. scorpioides), Creeping
Forget-me-not (M. secunda), Pale Forget-me-not (M. stolonifera),
Alpine Forget-me-not (M. alpestris) and Wood Forget-me-not
(M. sylvatica).
Five
Diptera miners, the agromyzids Agromyza
abiens, Agromyza
lithospermi, Agromyza
myosotidis, Agromyza
pseudorufipes and Phytomyza
myosotica, are recorded on Myosotis in Britain.
Elsewhere
the agromyzids Agromyza
abiens, Agromyza
myosotidis, Agromyza
pseudorufipes and Phytomyza
myosotica and the sciarid Phytosciara
halterata are recorded mining Myosotis.
One
non-Diptera miner, Orthochaetes
setiger, is recorded on Myosotis in Britain.
Elsewhere
three additional British non-Diptera miners are recorded on Myosotis
(see below).
N.B.
The key to the mines below includes mines recorded on Lithospermum
and Myosotis (Boraginaceae).
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Water
Forget-me-not
Myosotis scorpioides
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Key for the identification of the mines of British Diptera recorded on
Lithospermum and Myosotis
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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).
1a > Leaf-miner:
A narrow linear leaf mine, which developes into a large blotch.
Several larvae frequently feed together and the resulting mine can
entirely fill the leaf. Puparium reddish brown
On
numerous genera of Boraginaceae in Britain and elsewhere. Widespread
in Britain. Also recorded in the Republic of Ireland. Common and
widespread throughout most of Europe.
Agromyza
abiens Zetterstedt, 1848 [Diptera: Agromyzidae].
1b > Leaf-miner:
Larvae forming large blotch.
Agromyza
lithospermi Spencer, 1963 [Diptera: Agromyzidae].
1c > Leaf-miner:
Larva forming large, irregular blotch with a short linear section
in the first instar which is frequently entirely enveloped in the
fully developed mine and may then be no longer visible. Puparium
reddish brown
On
Lithospermum, Myosotis, Pentaglottis and Symphytum
in Britain and elsewhere. Also on Anchusa, Borago and Cynoglossum
elsewhere. Widespread in England and Europe. Also recorded in
Ethiopia.
Agromyza
myosotidis Kaltenbach, 1864 [Diptera: Agromyzidae].
1d > Leaf-miner:
A large blotch, larva frequently entering a second leaf to complete
development. Single larva. Primary and secondary feeding lines indistinct.
Frass in short thread fragments. Pupation outside the mine; exit
slit upper-surface
Agromyza
pseudorufipes Nowakowski, 1964 [Diptera: Agromyzidae].
1e > Leaf-miner:
Mine initially linear, later developing into a whitish blotch. Pupation
in mine on lower surface. Puparium yellowish orange
Phytomyza
myosotica Nowakowski, 1959 [Diptera: Agromyzidae].
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Key for the identification of British non-Diptera mines recorded on Myosotis
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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 at least 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).
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1a > Leaf-miner and case bearer: The larva lives outside the mine, protected by a case, and feeds on the underlying plant tisses via a hole cut in the epidermis. Mine does not contain frass (Coleophora species)
2
1b > Leaf-miner, but not a case-bearer: The larva lives mainly inside the mine. Mine usually contains frass. In later instars the larva may live sandwiched between two more or less circular sections cut from the leaf e.g. Incurvaria species.
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2 > Leaf-miner
and case-bearer:
The larva feeds in a distinctive case made from hairy leaf fragments
of the foodplant (UKMoths).
The young larva feeds on the developing seeds and hibernates in
its first case which is made of the tip of a petal. After hibernation
it makes a hoary, laterally flattened composite leaf case (resembling
a willow catkin). Full depth mines are made at the margin of the
leaves, that thereby look peculiarly damaged. Mouth angle 70°
(Bladmineerders
van Europa).
Initially
forms a blotch mine, in the centre of a leaf, which it excises for
its initial case. In the spring it repeatedly extends its case and
it resembles a jagged catkin of willow. The larva may wander from
its foodplant and attach to other plants or fences etc (British
leafminers).
Recorded
on Anchusa, Echium and Pentaglottis, but
not yet on Myosotis, in Britain and Anchusa,
Cynoglossum, Echium, Lithospermum, Myosotis, Nonea, Pentaglottis,
Pulmonaria and Symphytum elsewhere. South-east England
and East Anglia, with scattered records elsewhere including East
Kent and East Sussex. Widespread in continental Europe.
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Coleophora
pennella (Denis and Schiffermüller, 1775) [Lepidoptera:
Coleophoridae].
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3a > 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 (Bladmineerders
van Europa).
Recorded
on numerous genera and species of several plant families, but
not yet on Myosotis, in Britain. Recorded on
numerous genera and species of several plant families, including Myosotis elsewhere. Widespread in Britain and continental
Europe. Also recorded from the Channel Is.
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Cnephasia
incertana (Treitschke, 1835) [Lepidoptera: Tortricidae].
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3b > Leaf-miner:
Rather narrow corridor, untidy and sometimes branched, starting
from the base of the leaf, in particular the midrib. Sides of the
corridor irregularly eaten out, not really parallel. Frass mostly
present, and then in a central line. The legless larva is capable of leaving the mine and start a new one elsewhere. These later mines are much broader, and the frass is scattered irregularly. (Bladmineerders
van Europa.
Host
plants unknown in Britain. Recorded on numerous genera and
species in several plant families, including Myosotis,
elsewhere. Recorded in southern England. Widespread in continental
Europe.
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Orthochaetes
insignis (Aube, 1863) [Coleoptera: Curculionidae].
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3c > 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
(Bladmineerders
van Europa).
Recorded
on numerous genera and species in several plant families, including
Myosotis, in Britain and elsewhere. Widespread in England
and continental Europe. Also recorded in the Republic of Ireland.
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| Orthochaetes
setiger (Beck, 1817) [Lepidoptera: Curculionidae]. |
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