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Species Lycia ursaria - Stout Spanworm Moth - Hodges#6651

Representative Images

Stout Spanworm/ Bear moth, 6:06pm - Lycia ursaria - male Unidentified Moth - Lycia ursaria - male Unknown & Beautiful Caterpillar, head - Lycia ursaria Unidentified Moth 1 - Lycia ursaria - male moth 1 - Lycia ursaria Stout Spanworm? - Lycia ursaria - male Lycia ursaria female - Lycia ursaria - female Lycia ursaria
Show images of: caterpillars · adults · both

Classification

Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Geometroidea (Geometrid and Swallowtail Moths)
Family Geometridae (Geometrid Moths)
Subfamily Ennominae
Tribe Bistonini
Genus Lycia
Species ursaria (Stout Spanworm Moth - Hodges#6651)

Hodges Number

6651

Synonyms and other taxonomic changes

Lycia ursaria (Walker, 1860)
Biston ursaria Walker, 1860

Numbers

locally common

Size

wingspan to 45 mm
Full grown larvae are 50mm(1)

Identification

Adult: thorax and abdomen bulky, very hairy; male forewing broad, evenly gray, heavily speckled with black; three black wavy lines (sometimes broken) cross the wing; subterminal line white; hindwing similar but color more muted; female has reduced wings and does not fly

Range

southern Canada and northern United States, south to New Jersey and Iowa

Habitat

mixed and deciduous woods; males are nocturnal and come to light

Season

adult males fly from March to June
Larvae are present from May to July(1)

Food

Larvae feed on the leaves of alder, apple, ash, basswood, birch, blueberry, dogwood, elm, hawthorn, poplar, willow and other broadleaved trees and shrubs

Life Cycle

One generation per year
Overwinters as pupae in the ground(1)

Remarks

A bulky and very hairy moth, easily mistaken for a noctuid, notodontid, or other non-geometrid moth

See Also

Twilight Moth (Lycia rachelae) male lacks speckling on wings, and has yellowish strip along costa of forewing (compare images of both species at CBIF)
Woolly Gray (Lycia ypsilon) male has grayish-brown forewing with lighter median area, and a more southern distribution (doesn't occur in Canada)

Print References

Rindge, Frederick H. 1975. A revision of the New World Bistonini, (Lepidoptera, Geometridae). Bulletin of the AMNH ; v. 156, article 2.(2)

Internet References

Moth Photographers Group
pinned adult image of male (CBIF)
live adult image of male (Lynn Scott, Ontario)
distribution in Canada list of provinces (CBIF)

Works Cited

1.Eastern Forest Insects
Whiteford L. Baker. 1972. U.S. Department of Agriculture · Forest Service.
2.A revision of the New World Bistonini, (Lepidoptera, Geometridae).
Frederick H. Rindge. 1975. American Museum of Natural History 156(2):.
Contributed by Robin McLeod on 12 April, 2005 - 2:27am
Additional contributions by anitagould, Maury Heiman, marcie oconnor, Randy Hardy, Marci Hess, Robert H. Biagi
Last updated 25 August, 2023 - 3:55pm

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