The Tube-Web Spiders of the Genus Ariadna (Araneae: Segestriidae) from South Australia and Victoria

The tube-web spider genus Ariadna Audouin, 1826 has been revised for South Australia and Victoria, revealing a remarkable diversity, particularly centred in the arid north of South Australia. We describe 23 species as new, ten of which are supported by molecular data, where these were available. We recognise two species groups for some of the species based on a combination of genitalic morphology, macrosetae patterns and somatic characters: the clavata species group, which includes Ariadna clavata Marsh, Baehr, Glatz & Framenau, 2018 and A. spinosa sp. nov. from South Australia, and A. otwayensis sp. nov. and A. sinuosa sp. nov. from Victoria, and the formosa species group, including A. formosa sp. nov. and A. umbra sp. nov. from South Australia, and A. tria sp. nov. from Victoria. Seventeen new species could not be placed into these two species groups: A. arenacea sp. nov., A. bellatula sp. nov., A. curvata sp. nov., A. deserta sp. nov., A. diucrura sp. nov., A. flavescens sp. nov., A. inflata sp. nov., A. insula sp. nov., A. pollex sp. nov., A. propria sp. nov., A. rutila sp. nov., Ariadna simplex sp. nov., A. subplana sp. nov., A. una sp. nov., A. ungua sp. nov., A. valida sp. nov. and A. woinarskii sp. nov. We provide updated diagnoses and distributional data for A. clavata and A. tangara Marsh, Baehr, Glatz & Framenau, 2018; however, the holotype of A. burchelli (Hogg, 1900) from Victoria could not be located for this project.