A survey on poorly known rainforest litter-dwelling spiders of Orchid Island (Lanyu, Taiwan) with the description of a new species (Araneae: Linyphiidae, Tetrablemmidae, and Theridiosomatidae)

Two new species and a new genus of ray spiders (Araneae, Theridiosomatidae) from the Ryukyu Islands, southwest Japan, with notes on their natural history

This paper provides descriptions of two new theridiosomatid species, Theridiosomanigrivirgatum sp. nov. and Sennintanikawai gen. nov., sp. nov. from the Ryukyu Islands, southwest Japan, with photographs and illustrations of both sexes. Sennin gen. nov. is a troglophilic genus composed of two species, S.tanikawai sp. nov. (Iriomote Island, Japan) and S.coddingtoni (Zhu, Zhang & Chen, 2001), comb. nov. (southern China). Zomadibaiyin Miller, Griswold & Yin, 2009, which recently joined the Japanese fauna, was morphologically reexamined based on specimens from the Ryukyus, and taxonomic features of Zoma males were reassessed. A distributional map of theridiosomatid spiders in the Ryukyus is also provided, including T.dissimulatum Suzuki, Serita & Hiramatsu, 2020, and T.alboannulatum Suzuki, Serita & Hiramatsu, 2020 with their habitat types, web morphology, and web-building behavior in detail.

A newly-recorded species of the genus Ablemma Roewer, 1963 (Araneae, Tetrablemmidae) from China

Background

Ablemma Roewer, 1963 is a species-rich genus of the family Tetrablemmidae O. Pickard-Cambridge, 1873, currently comprising 28 known species. This genus is mainly distributed in Southeast Asia. Currently, only one species, A.prominens Tong & Li, 2008 is known to occur in China.

New information

The species Ablemmashimojanai (Komatsu, 1968), presently only known from the Ryuku Islands in Japan, is reported from China for the first time on the basis of material collected in Guangdong Province. A morphological description and detailed images are provided.