Insects of Britain and Ireland: the genera of Lepidoptera-Geometridae

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L. Watson and M. J. Dallwitz

Thera Stephens

Adults. Antennae of males bipectinate (T. firmata), or simple. Face rough.

Wingspan 24–35 mm. Forewings relatively narrow-elongate to relatively broad. The outer margin of the forewing convexly curved. Forewings not predominantly green, yellow, or black; whitish-fuscous, grey, olive-, reddish-ochreous, ochreous-brown or brown; predominantly whitish, or ochreous, or light brown, or brown, or pale fuscous, or pale grey, or grey; with a clear discal mark (usually, this blackish), or without a clear discal mark; with a distinct median band, or without a median band (the band usually more or less conspicuously dark, but occasionally obscure); without an oblique red stripe. The outer margin of the hindwings smooth. Hindwings plain; whitish, pale fuscous or pale ochreous; predominantly whitish, or pale ochreous, or pale fuscous; not predominantly green, yellow, or black; with a clear discal mark to without a clear discal mark; transversely lined (sometimes with a faint postmedian line), or without transverse lines.

Vein 10 of the forewings arising independently of 9; arising independently, anastomosing with 11 and 9 to form a double areole. Hindwings exhibiting a tubular vein 5. Vein 5 of the hindwings arising from about the middle of the transverse vein, or arising from below the middle of the transverse vein (?). Vein 8 of the hindwings approximated to or anastomosed with the upper margin of the cell to the middle or beyond. Hindwing veins 6 and 7 stalked.

Posterior tibiae of males 4-spurred.

Early stages. Larvae feeding on Pinus and Juniperus.

British representation. 5 species; South-east England, Central-southern England, South-west England, English Midlands, Northern England, Southern Scotland, Northern Scotland, Wales, and Ireland. Living adults found May to October (sometimes double brooded). T. cognata (Chestnut-coloured Carpet), T. cupressata (Cypress Carpet, adventive), T. firmata (Pine Carpet), T. juniperata (Juniper Carpet), T. obeliscata (Grey Pine Carpet), T. britannica (Spruce Carpet).

Subfamily. Larentiinae.

Illustrations. • 5 Thera spp., with Chloroclysta, Cidaria, Eulithis, Plemyria: Newman (1869). • T. juniperata (Juniper Carpet) and C. britannica (Spruce Carpet), with other Larentiinae (‘Carpets’): Kirby 50. • Larentiinae: Thera cognata (Chestnut-coloured Carpet: B. Ent. 519). • Thera cognata: B. Ent. 519, legend+text. • Thera cognata: B. Ent. 519, text cont..

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Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the genera of Lepidoptera-Geometridae. Version: 8th June 2016.’.