The cobweb spider subfamily Hadrotarsinae is generally regarded as the ant-eating group, consisting of 14 genera distributed worldwide, with seven genera distributed in East Asia. This group has a long and complex taxonomic history and remains under revision at the genus level. It is difficult to complete all the revision work in the short term because of the high species diversity and wide distribution. In addition, the evolutionary history and affinities of Hadrotarsinae are poorly known due to the lack of a stable phylogenetic hypothesis based on a wide taxon sampling. In recent years, although several morphological and/or molecular phylogenetic studies have showed the monophyly of hadrotarsines and revealed their positions within theridiid phylogeny, their internal evolutionary relationships remain unresolved due to limited taxon sampling within the group. In this study, we present the first molecular phylogenetic analysis focused on East Asian hadrotarsines, using molecular datasets of previous works as a backbone to explore phylogenetic relationships among these genera. Our results reveal that two hadrotarsine species, Dipoena pelorosa Zhu, 1998, and Euryopis galeiforma Zhu, 1998, are distantly related to the main East Asian hadrotarsine lineage, with the former forming a sister relationship to the lost colulus clade (Anelosiminae plus Theridiinae) plus Phoroncidia, and the latter nested within Theridiinae. Meanwhile, the main lineage of hadrotarsines is divided into five lineages, and the composition of the most lineages is associated with species from different genera. Based on morphological characteristics and the principle of maintaining clade monophyly, we propose nine nomenclatural changes, especially including a genus-level synonym, and all changes are as follows: Phycosoma submustelina (Zhu, 1998) comb. nov., Phycosoma ripa (Zhu, 1998) comb. nov., Phycosoma turriceps (Schenkel, 1936) comb. nov., Lasaeola wangi (Zhu, 1998) comb. nov., Lasaeola complexa (Gao & Li, 2014) comb. nov., and Yaginumena Yoshida, 2002 syn. nov. (= Lasaeola Simon, 1881), coincided with the transfer of all known Yaginumena species to Lasaeola. Furthermore, our dating analysis places the crown age of the hadrotarsines in the early Eocene.
Liu, J., Liang, Y., Yin, H. et al. Molecular phylogeny of the hadrotarsine genera from East Asia provides new insights for their affinities and positions within cobweb spiders (Araneae: Theridiidae: Hadrotarsinae). Org Divers Evol (2025). https://doi.org/10.1007/s13127-025-00670-5