Black Swallowtail
Papilio polyxenes

f25 @ 1/125s, ISO:2000, Nikon D3S w 105mm macro

"Papilio polyxenes," Wikipedia, the free encyclopedia. Papilio polyxenes, the (eastern) black swallowtail, American swallowtail or parsnip swallowtail, is a butterfly found throughout much of North America. The black swallowtail has a wingspan of 6.9–8.4 cm, and females are typically larger than males. The upper wing surface is black with two rows of yellow spots – these spots are large and bright in males and smaller and lighter in females. Females have a prominent blue area between these two rows, while males have a much less prominent blue area. These differences give rise to effective Batesian mimicry of Battus philenor seen in females. Both sexes show a red spot with a black bullseye on the inner hind margin of the hindwings and an isolated yellow spot on the front edge of the wings. The ventral side of wings of males and females are essentially identical: forewings have two rows of pale yellow spots, and hindwings have rows of bright orange spots separated by areas of powdery blue. The ventral side also acts as an effective mimic for both males and females for protection against predators.
Francis A. Crane Wildlife Management Area, East Falmouth, Massachusetts