Salticidae (Arachnida, Araneae) of Thailand: new species and records of Epeus Peckham & Peckham, 1886 and Ptocasius Simon, 1885

Abstract

The study is based on new material from the collections of the Naturalis Biodiversity Centre in Leiden (RNHM) and the Hungarian Natural History Museum (HNHM) and addresses issues in two genera: Epeus Peckham & Peckham, 1886 and Ptocasius Simon, 1885 from Thailand. Both genera are of Asian/Indomalayan origin, the latter with a diversity hotspot in the subtropical valleys of the Himalayas. Based on morphological data, we propose three new species of Epeus (Epeus daiqini sp. nov. (♂♀), Epeus pallidus sp. nov. (♀), Epeus szirakii sp. nov. (♀)) and two new species of Ptacasius (Ptocasius metzneri sp. nov. (♂♀) and Ptocasius sakaerat sp. nov. (♀)). Additionally, we redescribed E. tener (Simon, 1877) and added photographs of morphological characters. The genus Ptocasius is redefined due to the inclusion of 37 species, previously included in Yaginumaella Prószyński, 1979. Relationships and distribution of both genera are discussed in reference to molecular, morphological and distributional data, published by other authors in recent years.

Eleven species of jumping spiders from Sichuan, Xizang, and Yunnan, China (Araneae, Salticidae)

“…Those two genera share similar palpal structure, especially in having a cluster of setae antero-retrolateral to the bulb on cavity, the presence of tegular lobe, and the sclerotized RCA ; however, Epeus can be distinguished from Plexippoides by the following: 1) the slender body, covered with sparse setae on carapace (for illustrations, see Metzner 2024 ), versus rather dumpy body, setose on carapace in Plexippoides ( Logunov 2021 : figs 1, 6, 9, 14, 45, 50); 2) the most anterior margin of bulb cavity is far away from cymbial tip at least ca. one-third the cymbial length (for illustrations, see Metzner 2024 ), versus close to cymbial tip no more than one-third the cymbial length in Plexippoides (Lougunov 2021: figs 17, 23, 28); 3) the weakly sclerotized copulatory ducts run posteriorly and form multi-loops ( Patoleta et al 2020 ), but sclerotized copulatory ducts do not form similar loops in Plexippoides ( Logunov 2021 : figs 33, 37, 41). P. guangxi and P. dilucidus have slender bodies, and their most anterior margin of bulb cavity is far away from cymbial tip more than one-third the cymbial length ( Peng and Li 2002 : fig.…”

“… Yaginumaella , one of the members of the subtribe Plexippina Simon, 1901 ( Maddison 2015 ), contains 14 species mainly distributed in East Asia (WSC 2024). The genus has always been considered to be closely related to Ptocasius Simon, 1885 ( Li et al 2018 ; Patoleta et al 2020 ), and has even been considered as a synonym of the latter unofficially (e.g. Żabka 1985 ).…”

“… Żabka 1985 ). One of the influential studies of the two genera is Patoleta et al (2020) , who transferred 37 species of Yaginumaella into Ptocasius based on the similarities in copulatory organs structures. However, this work has not discussed the difference in habitus patterns (see Li et al 2018 ).…”

Thirteen species of jumping spiders from northern Vietnam (Araneae, Salticidae)

“… Yaginumaella , contains 13 species mainly restricted to East Asia ( WSC 2023 ). It was represented by nearly 50 species before Patoleta et al (2020) transferred 37 of them into Ptocasius . However, the decision to transfer the species requires further confirmation because it is only based on the similarity of copulatory organs and ignores habitus differences.…”

A review of the Ptocasius Simon, 1885 spiders of Gaoligong Mountains, China (Araneae: Salticidae)

“…The genus Ptocasius Simon, 1885 contains 52 species distributed in the Oriental region (World Spider Catalog 2023), the majority of them having been described from China and Bhutan (Simon 1885(Simon , 1902Thorell 1895;Peckham & Peckham 1907;Żabka 1980, 1981, 1985Logunov 1995Logunov , 2021Cao et al 2016;Liu et al 2016;Li et al 2018;Lin & Li 2020;Patoleta et al 2020;Peng 2020). Żabka (1980, 1981, 1985) revised the genus and recorded 27 new species from Bhutan, Myanmar and Nepal.…”