Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

See Moth submissions from National Moth Week 2023

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

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 Estigmene acrea - Salt Marsh Moth - Hodges#8131

Wooly Bear Caterpillar - Estigmene acrea Caterpillar Help - Estigmene acrea Possible Yellow Bear, Spilosoma virginica - Estigmene acrea Estigmene acrea? - Estigmene acrea Moth Caterpillar - Estigmene acrea Caterpillar on Marsh Marigold - Estigmene acrea Salt Marsh Moth - Estigmene acrea - male Spilosomina - Estigmene acrea
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Noctuoidea (Owlet Moths and kin)
Family Erebidae
Subfamily Arctiinae (Tiger and Lichen Moths)
Tribe Arctiini (Tiger Moths)
Subtribe Spilosomina
Genus Estigmene
Species acrea (Salt Marsh Moth - Hodges#8131)
Hodges Number
Other Common Names
Salt Marsh Caterpillar (larva), Salt Marsh Caterpillar Moth (adult), Salt Marsh Tiger (adult)
Estigmène dimorphe - En français… Ilze V-G.
Chenille des marais salants - En français… Ilze V-G.
Synonyms and other taxonomic changes
Estigmene acrea (Drury)
Orig. Comb: Phalaena acrea Drury, 1773
* phylogenetic sequence #930317
2 spp. n. of Mex. (2nd sp. restricted to AZ)
wingspan 45-68 mm
larvae length to 55 mm
Adult: forewing white with about 20 small black spots scattered across the disk, and 5 larger black spots spaced along the costa. Males have dark yellow hindwings, those of females are mostly white (with 3 or 4 black blotches in both sexes).
Larva (caterpillar): highly variable, blond to brown to black, with long bristly hairs standing upright in dense tufts from orange or black tubercles; hairs longer at both ends of body, especially toward the rear end. Spiracles white. Moves very rapidly.
Face mainly black with yellow down the center.

Ova (egg): spherical and yellow (1)
all of North America except Alaska and Yukon - Map (MPG)
open wooded areas, meadows, farm fields, weedy waste places, prairie grasslands, and marshes - including salt marshes; adults are nocturnal and come to light
Adults fly from May to September. Adults fly year round in Texas
Larvae feed on a wide variety of mainly weedy plants including anglepod (Gonolobus), dog fennel (Eupatorium capillifolium), ground cherry (Physalis), mallow (Anoda), milkweed (Asclepias), pigweed (Amaranthus), and sicklepod (Cassia tora), plus crops such as alfalfa, asparagus, bean, beet, cabbage, carrot, celery, clover, corn, cotton, lettuce, onion, pea, potato, soybean, sugarbeet, tobacco, tomato, and turnip. On rare occasions, they also feed on leaves of deciduous trees and shrubs: alder, apple, cherry, elderberry, pear, poplar, and serviceberry, according to Handfield.
Sequester pyrrolizidine alkaloids (PA) from their food plant. The caterpillars have specialized chemoreceptors that detect PA and stimulate feeding.(2)
Life Cycle
One generation per year in the far north, 2 in southern Quebec and Ontario, 3 or 4 generations in the south. Overwinters as a pupa in a spacious cocoon; adults emerge in early spring. Females lay 400-1200 eggs in clusters on leaves of host; eggs hatch in 4-5 days, and larvae pass through 5 instars over a period of 20-45 days; larvae are active dispersers, and are often found wandering over the soil in search of suitable food.

Life cycle images:
1. eggs. 2. early instar caterpillar on Cup Plant. 3 to 6. caterpillars, different instars and colors. 7. cocoon. 8. pupa. 9 and 10. adults
When disturbed the adults often drop to the ground, raise their wings, and emit an acrid odor from the prothoracic glands. Males (yellow hindwing) have inflatable appendages called coremata that will extend from the abdomen when gently squeezed.
See Here: ♂
In Arizona, the most common fly parasites of eggs and larva are E. mella, Gymnocarcelia ricinorum and Lespesia archippivora
See Also
Estigmene albida which has smaller and fewer black spots on the wings, and a more southern distribution (e.g. doesn't occur in Canada) - see pinned adult image by Bruce Walsh from Arizona.
Larvae of Virginian Tiger Moth are somewhat similar in some color forms, but seem to lack black facial markings, at least in BugGuide examples.
Print References
Covell, adult, p. 66, plate 13 #13,16) (3)
Wright, caterpillar and adult, pp. 98-99 (4)
Himmelman, caterpillar, plate A-2 (5)
Wagner, caterpillar, p. 464 (6)
Handfield, adult males, plate 60 #8131-1,2,3; adult female, plate 61 #8131-4; text, pp. 291-292 (7)
Powell, J. A. & P. A. Opler, Moths of Western North America, Pl. 47.19m, 47.22f; p. 269(8)
Internet References
Featured Creatures - John Capinera, U. of Florida
Works Cited
1.Tiger Moths and Woolly Bears: behavior, ecology, and evolution of the Arctiidae.
William E. Conner (ed.). 2009. Oxford University Press.
2.The Insects : Structure and Function
R. F. Chapman. 1998. Cambridge University Press.
3.Field Guide to Moths of Eastern North America
Charles V. Covell, Jr. 2005.
4.Peterson First Guide to Caterpillars of North America
Amy Bartlett Wright. 1998. Houghton Mifflin Company.
5.Discovering Moths: Nighttime Jewels in Your Own Backyard
John Himmelman. 2002. Down East Books.
6.Caterpillars of Eastern North America
David L. Wagner. 2005. Princeton University Press.
7.Les Guides des Papillons du Quebec
Louis Handfield. 1999. Broquet.
8.Moths of Western North America
Powell and Opler. 2009. UC Press.