Woolly-bear
Guides
Arctia virginalis
Ranchman's Tiger Moth, woolly bear caterpillar (larval form)
Arctia virginalis is a tiger moth species in the family Erebidae, found in western North America. The species was first described by Jean Baptiste Boisduval in 1852 and was formerly placed in the genus Platyprepia before being transferred to Arctia. Adults are brightly colored with black forewings bearing light yellow spots and orange hindwings with black bands. The larvae, known as woolly bears, are densely hairy caterpillars with distinctive orange-black-orange coloration. A 40-year population study at Bodega Bay, California, found that precipitation is the primary driver of abundance, with wet winters and wet sites supporting higher densities.
Hypercompe scribonia
Giant Leopard Moth, Great Leopard Moth, Giant Woolly Bear (larval stage), Black Woolly Bear (larval stage), Eyed Tiger Moth
Hypercompe scribonia, the giant leopard moth, is the largest eastern tiger moth in North America. Adults are striking white moths with black circular spots and bars, while larvae are known as giant woolly bears—large, densely hairy black caterpillars with red rings visible between body segments when curled. The species is nocturnal, with males frequently attracted to lights. Larvae overwinter and complete development in spring, feeding on a broad range of herbaceous and woody plants.
Pyrrharctia
woolly bear moth
Pyrrharctia is a genus of tiger moths in the family Erebidae, described by Packard in 1864. The genus contains two described species found in North and Central America. The best-known species, Pyrrharctia isabella, produces the familiar banded woolly bear caterpillar, widely recognized for its black and orange banded appearance and cultural association with winter weather prediction. The genus is notable for the freeze-tolerance adaptations of its larvae, which overwinter as caterpillars using cryoprotectant compounds to survive subfreezing temperatures.
Pyrrharctia isabella
Isabella tiger moth, banded woolly bear, woolly bear, woolly worm
Pyrrharctia isabella is a tiger moth species native to North America, best known for its larval form, the banded woolly bear caterpillar. The caterpillar is recognized by its alternating black and orange-brown bands and has become famous in North American folklore as a supposed predictor of winter weather severity. The species exhibits remarkable freeze tolerance, allowing larvae to survive winter temperatures by producing cryoprotectants that prevent lethal ice crystal formation. Adults are dull yellowish to orangish moths with sparse black wing spotting and bright reddish-orange forelegs.
Spilosoma
tiger moths, ermine moths
Spilosoma is a genus of tiger moths in the family Erebidae, established by John Curtis in 1825. The genus is taxonomically heterogeneous and widely acknowledged to require systematic revision, with many species likely needing reclassification into separate genera. Members are commonly known as tiger moths or ermine moths, with larvae often called 'woolly bears' due to their dense, colorful setae. The genus has a global distribution with particular diversity in tropical and temperate regions. Several species are significant agricultural pests, notably Spilosoma obliqua (Bihar hairy caterpillar) in South Asia, which causes severe defoliation of jute, legumes, and other crops.