In between the web and the ground: sexual encounters in the South American wolf spider Aglaoctenus oblongus

Abstract

Changes in the animals’ environment often impact on their behavior and the way they communicate. Particularly in spiders, living on webs or not is a determining factor. While the Lycosidae family predominantly comprises wandering spiders, only a few species inhabit webs. Aglaoctenus oblongus (C.L. Koch 1847) challenges this norm, as it has been found both in webs and wandering, suggesting a previously undocumented mixed strategy. This study aims to: (1) describe the sexual behavior of A. oblongus under laboratory conditions and (2) utilize phenological data to elucidate when and where mating occurs. Sexual encounters were observed within and outside webs, with minimal differences noted between them. Courtship was characterized by groping and leg shaking performed by the males. Copulation was lengthy (near to seven hours), featuring an irregular pattern of palpal insertions, and culminating in a backward dismount. Individuals showed a mixed life history, with the spiders most often found in webs being females with eggs. Both sexes were found throughout the year, with a peak in autumn. We compare the sexual characteristics of this species with that of A. lagotis (also belonging to the Sosippinae subfamily), the only other wolf spider studied to date that exclusively inhabits webs.