Re-delimitation of the genus Emertonella (Araneae, Theridiidae, Hadrotarsinae) and taxonomic notes on Euryopis and Phycosoma from China

Hadrotarsinae Thorell, 1881 is a subfamily of cobweb spiders (Theridiidae) distributed worldwide and generally regarded as specialized ant predators. The taxonomy of Hadrotarsinae is problematic due to unclear delimitation of genera, leading to likely misplacement of many species. In the current paper, we provide taxonomic amendments for <i>Emertonella</i> Bryant, 1945, <i>Euryopis</i> Menge, 1868, and <i>Phycosoma</i> O. Pickard-Cambridge, 1880 based on Chinese materials. Examination of <i>Eu. deplanata</i> Schenkel, 1936 and <i>Em. taczanowskii</i> (Keyserling, 1886) supports Yoshida's concept of <i>Emertonella</i> and provides additional morphological evidence for refining the generic diagnosis. Accordingly, <i>Eu. deplanata</i> is formally transferred, with 30 additional species, from <i>Euryopis</i> to <i>Emertonella</i>, and <i>Em. taczanowskii</i> is redescribed. Furthermore, <i>Physcoa mingyaoi</i> (Yin, 2012), <b>comb. nov</b>. ex. <i>Euryopis</i> and <i>Lasaeola stigmosum</i> (Yin, 2012), <b>comb. nov</b>. ex. <i>Phycosoma</i> are transferred, and one new synonym is proposed, <i>Phycosoma amamiense</i> (Yoshida, 1985), <b>syn. nov</b>. = <i>Phycosoma japonicum</i> (Yoshida, 1985). Finally, the first descriptions of the males of <i>Em. deplanata</i> (Schenkel, 1936), <b>comb. nov</b>. and <i>Phycosoma ripa</i> (Zhu, 1998) are provided.