SEXUAL REPRODUCTION

Butterflies locate potential mates by sight, identifying the wing colors and patterns characteristic of their species. In some types of butterflies, males and females display different patterns on their wings. In other species, the wing markings look the same to the human eye. But either the males or females often have scales on their wings that reflect ultraviolet light, producing patterns that enable the butterflies to distinguish one sex from the other. During the breeding season the males of some species stake out territories, where they perch and watch for females.

Once a male and female butterfly locate each other, the male initiates a courtship dance. Scientists believe that this ritual exposes the female to pheromones, chemical signals released by the male that induce the female to mate. Males of many species have patches of specialized scales called androconia on their wings, thorax, or abdomen that release pheromones. Females also release pheromones from their abdomens. The butterflies sense each other’s pheromones with the smelling organs on their antennae. During the courtship ritual, the male may flutter around the female or bump her with his wings or body. The pair may also alight on a plant or other perch and stroke each other with their antennae. In some species the courtship ritual is elaborate, but in most it is simple and brief.