Precipitation-dependent
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.