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

L. Watson and M.J. Dallwitz

Pseudoterpna Hübner

Adults. Relatively stout-bodied. Antennae of males bipectinate; apically simple. Face smooth.

Wingspan 35–40 mm. Forewings 1.75–1.85 times as long as wide. The outer margin of the forewing convexly curved. Forewings dull green, sprinkled white, with the wavy first and second lines dark green, and white-tipped cilia; with a clear discal mark (this dark green, linear). Hindwings plain; green, rather paler than the forewings and less distinctly marked; predominantly green when fresh; without a clear discal mark; faintly transversely lined (but the first line absent).

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 separate.

Posterior tibiae of males 4-spurred.

Early stages. Larvae feeding on Leguminosae, e.g. Cytissus, Genista, Ulex. Pupae on the surface of the ground (amongst dead leaves, etc., in a thin silken cocoon).

British representation. 2 species; South-east England, Central-southern England, South-west England, English Midlands, Northern England, Southern Scotland, Wales, and Ireland. Living adults found in July. P. pruinata atropunctaria (Grass Emerald).

Subfamily. Geometrinae.

Illustrations. • Geometrinae (‘Emeralds’): Kirby 44 (part). GEOMETRINAE. 12, Aplasta ononaria (Rest Harrow); 13, Chlorissa viridata (Small Grass Emerald); 14, Pseudoterpna pruinata (Grass Emerald); 15, Geometra papilionaria (Large Emerald); 16, Jodis lactearia (Small Emerald); 17, Comibaena bajularia (Blotched Emerald); 18, Thetidea smaragdaria (Essex Emerald); 19, Hemithea aestivaria (Common Emerald); 20, Thalera fimbrialis (Sussex Emerald); 21, Jodis lactearia (Little Emerald). • Geometrinae: Newman (1869). 1, Aplasta ononaria (The Rest Harrow); 2, Pseudoterpna pruinata (Grass Emerald); 3, Comibaena bajularia (Blotched Emerald); 4, Geometra papilionaria (Large Emerald); 5, Thetidia smaragdaria (Essex Emerald); 6, Jodis lactearia (Little Emerald); 7, Chlorissa viridata (Small Grass Emerald); 8, Hemistola chrysoprasaria (Small Emerald); 9, Hemithea aestivaria (Common Emerald). From Newman (1869).


We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, 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. See also Guidelines for using data taken from Web publications.


Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 2003 onwards. Insects of Britain and Ireland: the genera of Lepidoptera-Geometridae. Version: 14th February 2021. delta-intkey.com’.

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