Any of more than 500 species (genus Papilio , family Papilionidae) of
Some have tail-like extensions of the hind wing. Colour patterns vary with species, sex, season, and sometimes location (see {{link=tiger swallowtail">tiger swallowtail ). Most adults have yellow, orange, red, green, or blue markings on an iridescent black, blue, or green background. The brightly coloured larvae eat foliage. Some have markings resembling a snake's head, and many discharge a bad-smelling substance when disturbed. The giant swallowtail ( P. cresphontes ), with a wingspan of 4–5.5 in. (10–14 cm), is the largest butterfly in the U.S. and Canada.