Deciphering Butterflies: Large Black and Blue
It is thought that these three butterflies are so similar because, in an effort to avoid predation, the Black Swallowtail and Red-spotted Purple have evolved to mimic the distasteful Pipevine Swallowtail (Mullerian mimicry).
General Appearance – Large (3 1/4 – 4 1/4 inches), base color black
Range – Statewide
Status – Common, found season long
Dorsal – Sexually dimorphic, females almost uniformally black with the medial hindwing scaled in blue1, males have yellow medial bands on both the forewing and the hindwing2
Ventral – Base color black with orange, blue and orange bands on the hindwing
Black Swallowtail species page
General Appearance – Large (2 1/4 – 4 inches), base color dark blue, no tails on the hindwing
Range – Eastern 2/3 of state from June – August
Status – Locally common in woodland borders, rarer westward
Dorsal – Universally dark with some blue in the hindwing submarginal area
Ventral – Three orange spots near base of the hindwing1 along with orange submarginal row adjacent to blue lunules along the wings border2
Red-spotted Purple species page
General Appearance – Large dark swallowtail (2 3/4 – 5 inches)
Range – Stray
Status – Uncommon to rare stray
Dorsal – Uniformly dark with a metallic sheen on the hindwing
Ventral – Hindwing with orange spots surrounded by metallic blue1
Pipevine Swallowtail species page
