The Pieridae are members of the Superfamily Papilionoidea, the true butterflies. Worldwide in distribution, most species are found in the tropics. Adults have medium to small wings that are white, yellow, or orange, with some black or red, and many have hidden ultraviolet patterns that are used in courtship . Species with more than one generation usually have distinct seasonal variation in appearance . Adults of all species visit flowers for nectar, and adults of both sexes have three pairs of walking legs . Males patrol in search of receptive mates, and females lay columnar eggs on leaves, buds, and stems. The majority of caterpillars of North American whites and sulphurs feed on legumes or crucifers (members of the Mustard family ). Typically, temperate species overwinter in the pupal or larval stage , while tropical species overwinter as adults.