Different levels of polyandry in two populations of the funnel-web wolf spider Aglaoctenus lagotis from South America

Abstract

Populations of a species may show variation in mating systems, especially when the species is widely distributed. Aglaoctenus lagotis is a funnel-web wolf spider distributed in South America and with a ‘central Argentina form’ (CA) and a ‘southern Uruguay form’ (SU). Both forms differ in sexual behaviour, population density and copulatory season. This study evaluates the potential level of polyandry of both forms, sequentially exposing females to different males of their form under laboratory conditions. The number of copulations each female accepted and the characteristics of these sexual encounters were registered. CA females accepted more re-copulations than SU females and seemed to maintain more sexual attractiveness after the first copulation. In neither form was female re-copulation influenced by body characteristics, duration of the first copulation, ejaculation frequency or copulatory body shaking of females. Additionally, the PCA showed that both forms could be separated by their copulation behaviours. The higher level of polyandry in the CA form compared to the SU form suggested in our results adds another difference between these forms, currently under study to determine whether they are different species. This study is the first on mating systems in funnel-web wolf spiders, adding knowledge to the discussion about the evolution of sexual strategies in this group.