Systematics of the new Australian wolf spider genus Tuberculosa (Araneae:Lycosidae)

The new Australian wolf spider genus Tuberculosa is revised, with T. harveyi, sp. nov. from the Northern Territory as type species. The genus includes a further three species from northern Queensland: T. austini, sp. nov., T. hoggi (Framenau & Vink, 2001), comb. nov. and T. monteithi, sp. nov. The genus is defined by a unique sexual dimorphism: males carry modified tubercular setae on the ventral side of the third coxae, which are here compared to the knobbed setae that can be found on the ventral surface of the abdomen in Hygrolycosa rubrofasciata Ohlert, 1865 and Passiena torbjoerni Lehtinen, 2005 from two different lycosid subfamilies. Based on the structure of the male pedipalp, Tuberculosa belongs to the subfamily Lycosinae sensu Dondale (1986) with close affinities to Venatrix Roewer, 1960, because males of both genera have a tubercle on the outer edges of their fangs and the cymbium tip carries claw-like macrosetae. A cladistic analysis of all four Tuberculosa species, based on 12 morphological characters and with Venatrix konei (Berland, 1924) as outgroup, revealed a topology with T. austini and T. harveyi as sister-species in the most derived clade (V. konei (T. monteithi (T. hoggi (T. harveyi, T. austini))). The distribution of Tuberculosa in the tropical north of Australia supports an origin of the genus, as well as its putative sister-genus Venatrix, in the Palaearctic region, in contrast to all other Australian Lycosinae, which appear to be of Gondwanan origin.

Fighting success in relation to body mass and drumming activity in the male wolf spider Hygrolycosa rubrofasciata

In the wolf spider Hygrolycosa rubrofasciata, males court females by drumming dry leaves with their abdomen. Females prefer to mate with the most actively drumming males, and courtship drumming activity is also positively correlated with male viability. However, body mass of the males seems to have only a minor, if any, effect on female choice or male viability. There is also no correlation between male body mass and courtship drumming activity. We studied the effect of body mass and courtship drumming activity on the outcome of agonistic encounters between male H. rubrofasciata. For this purpose, males and females were randomly placed in a plastic arena, where male courtship drumming activity and agonistic encounters were recorded. Large differences in body mass and drumming activity between two rivals seemed to independently increase the probability of the larger or more active males winning. We conclude that while courtship drumming activity affects the fighting success of the males, and body mass more so, male–male interactions may not be of major importance in sexual selection of H. rubrofasciata.