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 <i>Platnickina</i> Koçak & Kemal, 2008 are described: <i>P. submaculata</i> Hu & Liu, <b>sp. nov.</b> (male, female) and <i>P. yoshidai</i> Hu & Liu, <b>sp. nov.</b> (male). Two new combinations, transferred from <i>Theridion</i> Walckenaer, 1805, are proposed: <i>P. obscuratum</i> (Zhu, 1998), <b>comb. nov.</b> and <i>P. xianfengense</i> (Zhu & Song, 1992), <b>comb. nov.</b> Three new species groups within <i>Platnickina</i> are established based on morphological characteristics: <i>antoni</i> group, <i>maculata</i> group, and <i>sterninotata</i> group. In addition, we discuss the relationships between <i>Platnickina</i> and the genera <i>Chrosiothes</i> Simon, 1894, <i>Coleosoma</i> O. Pickard-Cambridge, 1882, <i>Simitidion</i> Wunderlich, 1992, and <i>Theridion</i>.