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

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L. Watson and M. J. Dallwitz

Thalera Hübner


Adults. Antennae of males bipectinate; bipectinate to the apex.

Wingspan 33–39 mm. Forewings 1.6–1.9 times as long as wide. The outer margin of the forewing convexly curved. Forewings green; without a clear discal mark. The outer margin of the hindwings angled (with two points); scalloped (but with one conspicuous bite only). Hindwings conspicuously patterned; green; predominantly green when fresh; without a clear discal mark; transversely lined (with a contrasty, light second line and a terminal one).

Vein 10 of the forewings arising out of vein 9. Hindwings exhibiting a tubular vein 5. Vein 5 of the hindwings arising from well above the middle of the transverse vein. Vein 8 of the hindwings shortly anastomosed basally with the upper margin of the cell, thence rapidly diverging. Hindwing veins 6 and 7 stalked.

Posterior tibiae of males 2-spurred (likewise in the female).

Early stages. Larvae feeding on Achillea.

British representation. 1 species; Central-southern England, or South-west England (first recorded in 1902, and rarely seen). Living adults found July and August. T. fimbrialis (Sussex Emerald).

Subfamily. Geometrinae.

Illustrations. • Geometrinae (‘Emeralds’): Kirby 44 (part).

To view the illustrations with detailed captions, go to the interactive key. This also offers full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, and distributions of character states within any set of taxa.

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.’.