The left side of this tiger swallowtail (Papilio gynandromorph) is a female and the right side is a male. The most striking difference between the sexes is the difference in width of the black bands (the female's are noticeably thicker). Also the characteristic blue markings on the female side of the hind wing are greatly reduce on the male side, also a characteristic difference between the sexes. Butterfly gynandromorphs are exceedingly rare, but this one was discovered among the hundreds of butterflies that raised in the Porter lab this summer as part of their work in butterfly genetics.