North American Ecology (US and Canada)

Euphydryas editha is resident to the northwest United States and southwest Canada (Scott 1986). Habitats are mountains, typically on ridgetops, from coastal chaparral and transition zone open woodland to alpine tundra. Host plants are usually annual herbs, known hosts include species from many families including Scrophulariaceae, Valerianaceae, Plantaginaceae, and Caprifoliaceae. Eggs are laid on the host plant in clusters of 20-350 eggs per clutch. Individuals overwinter as third and fourth instar larvae, often under stones. All stages are slightly poisonous to vertebrates. There is one flight each year with the approximate flight time Mar.1-Apr.30 on Calif. coast, June1-30 in the Great Basin, late June-early Aug. at high altitude (Scott 1986).