I was photographing flower flies when this Question Mark butterfly landed at my feet. How could I resist taking a few photos? This butterfly is in Question Mark's winter form. The hindwings are almost totally black on the summer form. According to Butterflies and Moths of North America: Overwintered adults fly and lay eggs in the spring until the end of May. The summer form emerges and flies from May-September, laying eggs that develop into the winter form; these adults appear in late August and spend the winter in various shelters.
A complete set of photos showing inner and outer wings on both summer and winter forms is available on the Massachusetts Butterfly Club site. These photos also show the question mark from which this butterfly's name is derived.
Range: Southern Canada and all of the eastern United States except peninsular Florida, west to the eastern edge of the Rocky Mountains, south to southern Arizona and Mexico.
Question Marks overwinter as adults and seek shelter in wood piles and bark crevices. In colder climates many migrate south before overwintering, but some stay in place even as far north as New England.
According to Massachusetts Audubon: Larval host plants include elms, nettles, False Nettle, and hackberry.
Adult Food Sources: While this species has been recorded at milkweeds and asters, like other anglewings the Question Mark prefers to visit sap and rotting fruit, and even carrion or scat. This adaptation seems especially well suited to the late summer- overwintering-early spring brood whose nectar sources, at least in the northern part of its range, may be limited.
More information and photos are also available at BugGuide.
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