| | Insects of Britain and Ireland: the genera of Lepidoptera-Geometridae |
Amphidasis, Amphidasys, Eubyja, Pachys.
Adults. Nocturnal; relatively stout-bodied. Antennae of males strongly bipectinate; bipectinate to the apex, or apically simple. Face rough (hairy or rough-scaled). Tongue fully developed, or absent.
Wingspan 45–62 mm. Forewings relatively narrow-elongate. The outer margin of the forewing convexly curved to more or less straight. Forewings whitish, strigulated brown and black, with a brown band after the second line (B. strataria); white, strigulated and densely peppered with black (B. betularia), or almost entirely black (melanic B. betularia); with a clear discal mark (dark), or without a clear discal mark. Forewings of the male without a fovea. Hindwings conspicuously patterned; whitish, peppered grey (especially basally), tinged reddish outside the second line (B. strataria); white, densely peppered and lined with black (B. betularia), or mainly black (melanic B. betularia); with a clear discal mark (perhaps, in B. betularia), or without a clear discal mark; transversely lined (B. strataria with no first line but a clear median, the outer lines more or less detectable but usually incomplete in B. betularia).
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.
The abdomen conspicuously patterned (speckled), or plain.
Early stages. Larvae feeding on foliage of Quercus, Ulmus, Betula, Salix, Fraxinus, etc.
British representation. 2 species; South-east England, Central-southern England, South-west England, English Midlands, Northern England, Southern Scotland, Northern Scotland, Wales, and Ireland. Living adults found March and April (B. strataria), or May and June. B. strataria (Oak Beauty); B. betularia (Peppered Moth).
Subfamily. Ennominae.
Illustrations. • Biston betularia (Peppered Moth, typical and melanic forms), cf. Biston strataria (photos). Figs. 1–6, Peppered Moth (Biston betularia; Figs. 7–8, Oak Beauty (Biston strataria).
Figs 1 and 4–6 depict the Peppered Moth as represented in mixed deciduous woodland around Leek, N. Staffs, during the decade 1948–1958 before implementation of a "Clean air Act" in Britain. Localities "rural", but about 10 and 30 miles miles from the heavily industrial regions of Stoke-on-Trent and Manchester, respectively. Melanic individuals commonly came to light in the summer. They are exemplified by Fig. 6, seemingly representing the full melanic carbonaria form, and Figs. 4 and 5, which may represent the insularia complex. Fig. 1 portrays the only “normal” (typica) specimen encountered there in the decade, with Figs. 2 and 3 representing typica specimens from Holme Fen and Cirencester (Glos.) respectively.
The Peppered Moth affords a spectacular example of industrial melanism, and has been intensively studied in that context by population geneticists. A brief summary of the phenomenon, and of the status of the Peppered Moth in that context, are summarised in our accompanying ‘Families of Lepidoptera’ data set. For detailed discussion, see Majerus (1998, 2002).
Imagines of the Oak Beauty (B. strataria, Figs 7 and 8) were to be found resting by day on the trunks of oak trees in Spring. Unlike B. betularia, this species has never exhibited industrial melanism in Britain, although it does so in mainland Europe.
Specimens: 1, Leek, Staffs., July 1955; 2, Holme Fen, August 1956; 3, Cirencester, Glos., 1951 (S.G. Smith); 4–6, Leek, Staffs., June 1954; 7–8, Leek, Staffs., April 1952. From Watson’s collection. • Alcis, Biston, Cleora, Cleorodes, Deileptenia, Fagivorina, Menophra, Ourapteryx, Peribatodes, Selidosema: Newman. 1, Ourapteryx sambucaria (Swallow-tailed Moth); 2, Biston betularia (Peppered Moth); 3, Biston strataria (Oak Beauty); 4, Peribatodes rhomboidaria (Willow Beauty); 5, Menophra abruptaria (Waved Umber); 6, Cleora cinctaria (Ringed Carpet); 7a-b, Selidosema brunnearia scandinaviaria (Bordered Grey, male and female); 8, Alcis repandata (Mottled Beauty); 9, Alcis jubata (Dotted Carpet); 10, Fagivorina arenaria (Speckled Beauty); 11, Cleorodes lichenaria (Brussels Lace); 12, Deileptenia ribeata (Satin Beauty). From Newman, 1869. • Oenochrominae and Ennominae: Kirby 47. OENOCHROMINAE. 17, Alsophila aescularia (March Moth). ENNOMINAE. 1, Epione vespertaria (Dark Bordered Beauty); 2, Epione repandaria (Bordered Beauty); 3, Cepphis advenaria (Little Thorn); 4, "Hypoplectis adspersaria", = ?; 5, Pseudopanthera macularia (Speckled Yellow); 6, Eilicrinia cordiaria; 7, Semiothisa alternaria (Sharp-angled Peacock); 8, Semiothisa signaria ; 9, Semiothisa liturata (Tawny Barred Angle); 10, cf. Epirrhanthis diversata; 11, Theria primaria (Early Moth); 12, Agriopis bajaria; 13, Agriopis leucophaearia (Spring Usher); 14, Agriopis aurantiaria (Scarce Umber); 15, Agriopis marginaria (Dotted Border); 16, Erannis defoliaria (Mottled Umber); 18, Phigalia pilosaria (Pale Brindled Beauty); 19, Apocheima hispidaria (Small Brindled Beauty); 20, Lycia pomonaria; 21, Lycia zonaria (Belted Beauty); 22, Lycia hirtaria (Brindled Beauty); 23, Biston strataria (Oak Beauty); 24, Biston betularia (Peppered Moth); 25, Menophra abruptaria (Waved Umber); 26, "Nychiodes lividaria", cf. Eunychiodes amygdalaria?. From Kirby 47, with updated names.
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’.
