North American Ecology (US and Canada)
is a year-round resident in Calif. and s. Fla. and migratory through most of North America (Scott 1986). The eastern population exhibits a fantastic and unique migratory habit, with adults overwintering in a small forest are in central Mexico and spring migrants laying eggs and expanding over several generations until they reach Canada in late summer. California populations overwinter in forest stands along the coast and migrate inward. Populations in south Florida do not migrate. Breeding habitats are mostly open places, esp. moist valley bottoms, breeding from the subtropics to the lower Canadian zone. Host plants are herbaceous and include many species but restricted mostly to family Asclepiadaceae
. Eggs are laid on the host plant singly. Individuals overwinter as adults, by roosting in trees. There are five or more flights all year in Calif. and s. Fla.; in New Mexico and s. Nev. several flights Mar.10-Nov.30; in the northeast May1-Oct31; in Nfld, Aug1-Oct.31. (Scott 1986).
Scott, J. A. 1986. The butterflies of North America. Stanford University Press.