Arácnido Taxonomy

  The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae) Abstract The morphological characters of copulatory organs are the most important basis in spiders for identification. In theridiids, a vulva with four sac-like structures is mostly associated with the subfamily Hadrotarsinae but has never been recorded in Theridiinae. Based on specimens collected from subtropical forest canopies in China, a new Theridiinae genus that has four sac-like structures in the vulva is described: Sactheridion gen. nov., with the type species S. chuan gen. & sp. nov. from Sichuan Province, China. Photos, diagnosis, description, and a distribution map of the new genus and new species are provided. Hu, C., Yao, Z., Liu, J. & Xu, X. (2026) The first genus with four sac-like structures in the vulva in the cobweb spider subfamily Theridiinae Sundevall, 1833 (Araneae: Theridiidae). Zootaxa, 5884 (1), 167–175. http...