Junonia coenia (also known as Precis coenia) is a beautiful butterfly with conspicuous eyespots on both the fore- and hind-wings.  This species occurs through much of the United States, northern Mexico and Cuba, and frequents open, sunny habitats with some bare ground.  Caterpillars feed on plantain, snapdragon, Gerardia spp. (3), figworts, and vervains (2).  By incorporating toxins (iridoid glycosides) from these plants, the caterpillars deter predatory ants (2).  It cannot survive winters in the north, and in the autumn migrates overwinters in the deep South.  Junonia coenia has several generations each year.  In the autumn generation the underside of the wings is dark brown, but in the generations that grow up in the summer the undersides are a pale tan.  This difference in pigmentation is controlled by ecdysone, a steroid hormone, whose secretion is affected by the shortening days in the autumn.