ARCTIUM. Burdocks. [Asteraceae]

Four species of Arctium are recorded in Britain. These include the native species Greater Burdock (A. lappa), Lesser Burdock (A. minus) and Wood Burdock (A. nemorosum).

Five Diptera miners, the agromyzids Chromatomyia 'atricornis', Chromatomtia syngenesiae and Phytomyza lappae, the anthomyiid Pegomya laticornis, and the tephritid Cryptaciura rotundiventris are recorded on Arctium in Britain, although the record of C. rotundiventris on Arctium requires confirmation.

The agromyzids Liriomyza huidobrensis and Liriomyza trifolii, polyphagous pest species of ornamental and vegetable crops occasionally intercepted at UK points of entry, are recorded on Arctium. Both species have been found under glass in England and Wales. All populations have been and continue to be eradicated.

The agromyzid Melanagromyza lappae is recorded boring the stems of Arctium in Britain and elsewhere.

Elsewhere the agromyzids Chromatomyia 'atricornis', Chromatomyia syngenesiae, Liriomyza huidobrensis, Liriomyza strigata, Liriomyza trifolii, Phytomyza continua and Phytomyza lappae, the anthomyiid Pegomya laticornis, and the tephritids Acidia cognata, Euleia heraclei and Trypeta zoe and the sciarid Phytosciara halterata are recorded mining Arctium.

Two non-Diptera mines, Coleophora paripennella and Coleophora peribenanderi, are recorded on Arctium in Britain (see below).

Elsewhere two additional British non-Diptera mines, Agonopterix propinquella and Cnephasia incertana, are recorded on Arctium (see below).

A key to the European miners, based on characteristics of the mines, immature stages and where relevant the larval cases, recorded on Arctium is provided in Bladmineerders van Europa. This includes Apterona gracilis, Coleophora onopordiella, Coleophora paripennella, Coleophora peribenanderi, Sphaeroderma rubidum, Agonopterix carduella, Tebenna micalis, Phytosciara macrotricha, Cnephasia incertana, Cnephasia asseclana, Cnephasia stephensiana, Agonopterix arenella, Agonopterix subpropinquella, Agonopterix propinquella, Phytomyza continua, Phytomyza lappivora, Liriomyza strigata, Chromatomyia 'atricornis', Phytomyza lappae, Pegomya laticornis, but not Phytosciara halterata, Phytosciara macrotricha, Chromatomtia syngenesiae, Cryptaciura rotundiventris, Liriomyza huidobrensis or Liriomyza trifolii

N.B. The key to mines below includes mines recorded on Arctium and Serratula (Asteraceae).

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

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 > 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 > Miner, but not a case-bearer, although it may live sandwiched between two more or less circular sections cut from the leaf in later instars e.g. Incurvaria species. The larva lives mainly inside the mine. Mine usually contains frass

3

2a> Leaf miner and case-bearer: Larva mines leaves (British leafminers). The larva builds a case from silk, resembling a razor shell in appearance. (UKMoths). The full-grown case is 12 mm long and blackish-brown (British leafminers). The full grown larva lives in a blackish brown trivalved tubular silken case of about 8 mm. The mouth angle is 0°-10°, causing the case to lay almost flat on the leaf (Bladmineerders van Europa).

Recorded on Arctium, Centaurea, Cirsium, Serratula in Britain and Arctium, Carduus, Centaurea, Cirsium, Saussurea and Serratula elsewhere. Widespread in Britain, Ireland and continental Europe.

Coleophora paripennella Zeller, 1839 [Lepidoptera: Coleophoridae]

2b> Leaf miner and case-bearer: The larva forms a case, approximately 11-12 mm long, beneath a thistle leaf, although burdock may sometimes be used. The shape of the ochreous case varies as, when being enlarged, it is elongated first, and the girth increased subsequently (UKMoths). Yellow-brown to light grey tubular silken case with darker length lines. The case is fairly large (up to 17 mm) and very slender. The rear end is three-valved, the mouth angle about 50°. The larva feeds at the underside of the leaf (Bladmineerders van Europa).

Recorded on Arctium, Carduus and Cirsium in Britain and Arctium, Carduus, Carlina, Centaurea and Cirsium elsewhere. England, Wales and southern Scotland. Also recorded in the Republic of Ireland. Widespread in continental Europe.

Coleophora peribenanderi Toll, 1943 [Lepidoptera: Coleophoridae]

Recorded on Cirsium arvense and Cirsium vulgare, but not yet on Arctium, in Britain plus Arctium, Carduus, Centaurea, Cynara, Mycelis and Serratula elsewhere. Widespread in Britain and continental Europe.

Agonopterix propinquella (Treitschke, 1835) [Lepidoptera: Depressariidae]

3b > 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 plant families, but not yet on Arctium, in Britain. Recorded on numerous genera and species of plant families including Arctium elsewhere. Widespread in Britain and continental Europe. Also recorded from the Channel Is.

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