Leks and hilltopping in insects

Abstract

Insects of many groups form mating aggregations on hilltops. Males of some hilltopping species behave like certain classic lekking vertebrates, notably in their defense of territories that are devoid of resources useful to females but which are visited by females solely for mating. But even within a sample of 11 hilltopping insects found in the same habitat in central Arizona, there is considerable diversity with respect to resources transferred to mates by males, the degree to which males are aggregated and territorial, and the extent to which females can choose freely among hilltopping males. Thus ‘hilltopping’ is not a single mating system type; although some species conform closely to the traditional definition of a lek, others are very different. The ecological basis for the diversity in the behaviour of male hilltopping insects appears linked to differences in population density, which affect the costs of territoriality, and differences in the nature of female choice, which are little understood as yet.