MYOSOTIS. Forget-me-nots. [Boraginaceae]

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).

Key for the identification of British non-Diptera mines recorded on
Myosotis

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).

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)

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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.

 

Coleophora pennella (Denis and Schiffermüller, 1775) [Lepidoptera: Coleophoridae].

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).

Cnephasia incertana (Treitschke, 1835) [Lepidoptera: Tortricidae].

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.

 

Orthochaetes insignis (Aube, 1863) [Coleoptera: Curculionidae].

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.