Species Details

Biston betularia

University of Alberta E.H. Strickland Entomological Museum Read more about this collection »

Common NamePepper & Salt Geometer SeasonalityFlies from May to July, peaking in mid-June. IdentificationA large heavy-bodied geometrid. Wings light grey with black speckling and a well-defined black AM and PM line. Lycia ursaria has a less pointed forewing apex and lacks the black-on-white speckled appearance; Nacophora quernaria is similar, but has yellowish-ochre shading in the subterminal area which is absent in B. betularia. This species also occurs in the Palaearctic region, and North American populations are assigned to subspecies cognataria (Gn.) by some.

Scientific Name Biston betularia Common Name Pepper & Salt Geometer Habitat Widespread in deciduous and mixedwood forests, parklands and shrublands. Seasonality Flies from May to July, peaking in mid-June. Identification
A large heavy-bodied geometrid. Wings light grey with black speckling and a well-defined black AM and PM line. Lycia ursaria has a less pointed forewing apex and lacks the black-on-white speckled appearance; Nacophora…
A large heavy-bodied geometrid. Wings light grey with black speckling and a well-defined black AM and PM line. Lycia ursaria has a less pointed forewing apex and lacks the black-on-white speckled appearance; Nacophora quernaria is similar, but has yellowish-ochre shading in the subterminal area which is absent in B. betularia. This species also occurs in the Palaearctic region, and North American populations are assigned to subspecies cognataria (Gn.) by some.
Life History
A detailed description of the immature stages is given by McGuffin (1977). The eggs are laid in bark crevices and old alder catkins, and hatch in about 12 days. Over 600 eggs may be laid by a single female over the…
A detailed description of the immature stages is given by McGuffin (1977). The eggs are laid in bark crevices and old alder catkins, and hatch in about 12 days. Over 600 eggs may be laid by a single female over the course of several weeks. Larvae are twig mimics, and pupation occurs in the soil prior to the onset of winter (McGuffin 1977). The increase in frequency of the melanic form of B. betularia in conjunction with industrial pollution in Great Britain is often cited as a classic example of direct evidence of natural selection; tree trunks blackened by air pollution favored the survival of the black form, which were supposedly less visible to birds than the typical pale form. Following air quality legislation, the frequency of the black form has again declined, both in Europe and the industrial northern Great Lakes region in North America (Grant & Wiseman 2002).
Conservation Common and widespread; not of concern. Diet Info
Larvae feed on a wide range of trees and shrubs (over 50 species reported), and were most often collected from willow (Salix spp.), white birch (Betula papyrifera), alder (Alnus spp.), larch (Larix laricina) poplars…
Larvae feed on a wide range of trees and shrubs (over 50 species reported), and were most often collected from willow (Salix spp.), white birch (Betula papyrifera), alder (Alnus spp.), larch (Larix laricina) poplars (Populus spp.), and Manitboa Maple (Acer negundo) by the Forest Insect and Disease Survey (Prentice 1963).
Range Occurs from coast to coast across Canada, from Fort Simpson NWT south to North Carolina and Chihuahua, MEX (McGuffin 1977).

Citation

Page Citation for Biston betularia

Page Citation

"Species Details - Biston betularia, University of Alberta E.H. Strickland Entomological Museum." University of Alberta Museums Search Site, https://search.museums.ualberta.ca/g/2-3978. Accessed 26 Sep. 2022.

Taxonomic Hierarchy

Kingdom Animalia Phylum Arthropoda Class Hexapoda Subclass Insecta Order Lepidoptera Suborder Ditrysia Superfamily Geometroidea Family Geometridae Subfamily Ennominae Tribe Bistonini Genus Biston Species Biston betularia
This hierarchy is created from our museum records, it may not always accurately reflect modern taxonomies.

Taxonomic Hierarchy for University of Alberta E.H. Strickland Entomological Museum