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

L. Watson and M.J. Dallwitz

Isturgia Hübner

Adults. Antennae of males bipectinate; apically simple. Face rough (with projecting scales).

Wingspan 26–30 mm. The outer margin of the forewing convexly curved. Forewings orange yellow, black-bordered around costa and termen; without a clear discal mark. Forewings of the male with a fovea. Hindwings rather conspicuously patterned (with peripheral blackish rays coalescing with the blackish border of the outer margin); orange-yellow, with dark border; orange- predominantly yellow; without a clear discal mark; without transverse lines.

Hindwings lacking a tubular vein 5. 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 separate.

Posterior tibiae of males 4-spurred.

Early stages. Larvae feeding on Cytissus.

British representation. 1 species; South-east England and Northern Scotland. Living adults found June and July. I. limbaria (The Frosted Yellow).

Subfamily. Ennominae.

Illustrations. • Cepphis, Epione, Isturgia, Opisthograptis, Pachycnemia, Petrophora, Plagodis, Pseudopanthera: Newman. 1, Isturgia limbaria (Frosted Yellow); 2, Cepphis advenaria (Little Thorn); 3, Petrophora chlorosata (Brown Silver-line); 4, Plagodis pulveraria (Barred Umber); 5, Plagodis dolabraria (Scorched Wing); 6a, Epione repandaria (Bordered Beauty); 6b-c, Epione vespertaria (male and female Dark Bordered Beauty, = E. repandaria); 7a, Pseudopanthera macularia (Speckled Yellow); 7b, P. macularia variety; 8a-b, Pachycnemia hippocastanaria (Horse Chestnut); 9, Opisthograptis luteolaria (Brimstone). 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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