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Upcoming Events

Photos of insects and people from the 2022 BugGuide gathering in New Mexico, July 20-24

National Moth Week was July 23-31, 2022! See moth submissions.

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Photos of insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Previous events


Species Ennomos subsignaria - Elm Spanworm - Hodges#6798

Snowy Geometer Moth - Ennomos subsignaria - male Maple Spanworm munching on hickory - Ennomos subsignaria Moth with Tall Antennae - Ennomos subsignaria - male Ennomos subsignaria - Elm Spanworm moth? - Ennomos subsignaria  Elm Spanworm - Ennomos subsignaria - male elm spanworm - Ennomos subsignaria Elm Spanworm - Hodges #6798 (Ennomos subsignaria) - Ennomos subsignaria - male Texas SE Gulf Coast - Ennomos subsignaria - male
Show images of: caterpillars · adults · both
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 Ennomini
Genus Ennomos
Species subsignaria (Elm Spanworm - Hodges#6798)
Hodges Number
Synonyms and other taxonomic changes
Ennomos subsignaria (Hübner, [1823])
Ennomos niveosericeatus (Harris, 1855)
Eudalimia subsignaria Hübner, 1823
Phylogenetic sequence # 911229
wingspan in the 35-40 mm range (BG images)
"Pure white except for yellow branches on bipectinate antennae. [of the males] Easily separated from other all-white species by angled outer margin of FW."
[description by Charles Covell (1)]

Some individuals have a significant amount of green coloring on the wings and legs and sometimes part of the antennae:
from Texas to Alberta and east to the Atlantic
adults fly in July and August, earlier (late April-June) in Texas and southern states
larvae present from May to July
larvae feed on elm, apple, birch, maple, and oak
Life Cycle
one generation a year
Eggs, larva, larva, pupa, adult male, adult female:
See Also
Eugonobapta nivosaria - Snowy Geometer - Hodges#6965
Shape of forewing is different.
Internet References
adult images (Larry Line, Maryland)
several images and biology info (Pennsylvania State U.)
live larva image (
common name reference and other info (Ohio State U.)
Works Cited
1.Field Guide to Moths of Eastern North America
Charles V. Covell, Jr. 2005.