Make it simple: mating behaviour of Euphydryas aurinia provincialis (Lepidoptera: Nymphalidae)

Courtship in butterflies can vary among species, from simple to elaborate displays, which are thought to promote conspecific mating and drive a female, at first unreceptive, to eventually mate. In this paper, we studied the courtship behaviour of a population of E. aurinia provincialis (Nymphalidae) of the Italian region Latium, finding clear differences in acceptance/refusal of females and in consequent departure/persistence of males. Despite the presence of a period of female unreceptivity after eclosion, virgin females usually do not show resistance, and accept to mate after a simple courtship. Once males meet a female, they immediately try to copulate clasping female genitalia, and proceed in mating performing long copulations. They also secrete a mating plug to prevent subsequent matings. On the contrary, already-mated females can strongly reject any approaching male and they always display Wide Wing fluttering, which is a behavioural pattern usually followed by male departure. In case of persistent males, prolonged and energy demanding sexual interactions, as Carrousels, can occur, with rare final copulation. Here, we analyse the effects of female refusal on male sexual behaviour and discuss potential selective pressures that might be acting on such behavioural traits.