Taxonomic notes of the cobweb spider genus Platnickina Koçak & Kemal, 2008 (Araneae, Theridiidae, Theridiinae), with descriptions of two new species from southern China

Based on specimens collected from southern China, two new species of Platnickina Koçak & Kemal, 2008 are described: P. submaculata Hu & Liu, sp. nov. (male, female) and P. yoshidai Hu & Liu, sp. nov. (male).

Two new combinations, transferred from Theridion Walckenaer, 1805, are proposed: P. obscuratum (Zhu, 1998), comb. nov. and P. xianfengense (Zhu & Song, 1992), comb. nov. Three new species groups within Platnickina are established based on morphological characteristics: antoni group, maculata group, and sterninotata group. In addition, we discuss the relationships between Platnickina and the genera Chrosiothes Simon, 1894, Coleosoma O. Pickard-Cambridge, 1882, Simitidion Wunderlich, 1992, and Theridion.