 Courtship is often aerial and often involves pheromones. Butterflies then land on the ground or on a perch to mate. Copulation takes place tail-to-tail and may last from minutes to hours. The male passes a spermatophore to the female; to reduce sperm competition, he may cover her with his scent, or in some species such as the Apollos (Parnassius) plugs her genital opening to prevent her from mating again.
