Distinctive large black-and-white swallowtail with long tails. Summer flight is darker, form
lecontei. (1)
Larva "ringed with narrow green, white, blue, yellow and/or black bands...Body widest at leading ege of A1 where body is ringed by tricolred band: blue-white towards thorax, followed by black...followed by yellow." Each abdominal segment also crossed by a yellow ring.
(2) Another larval form occurs which is largely black. Young larvae may also be black. Stripes are less prominent in final instar but A1 stripe is still noticeable.
