Operophtera
Guides
Operophtera occidentalis
Western Bruce Spanworm
Operophtera occidentalis, commonly known as the Western Bruce Spanworm, is a moth species in the family Geometridae. It is native to western North America. The species is closely related to the Bruce spanworm (Operophtera bruceata), with which it shares similar ecological traits and appearance. Adults are active in late autumn, with males possessing fully developed wings while females are wingless.