Tanasevitch A.V.1, Marusik Yu.M.2,3,4 2026. Reassessment of the spider genus Hilaira Simon, 1884. I. Revalidation of the genus Arctilaira Chamberlin, 1921 (Aranei: Linyphiidae) // Invert. Zool. Vol.23. No.1: 114–135 [in English].
1 A.N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky prospekt 33, Moscow 119071 Russia.
2 Institute for Biological Problems of the North FEB RAS, Portovaya Str. 18, Magadan 685000 Russia.
3 Altai State University, Lenina Pr., 61, Barnaul, 656049 Russia.
4 Department of Zoology & Entomology, University of the Free State, Bloemfontein 9300, South Africa.
Andrei V. Tanasevitch: tanasevitch@gmail.com or and-tan@mail.ru https://orcid.org/0000-0002-9116-606X
Yuri M. Marusik: yurmar@mail.ru https://orcid.org/0000-0002-4499-5148
doi: 10.15298/invertzool.23.1.07
ABSTRACT. The genus Arctilaira Chamberlin, 1921, previously treated as a junior synonym of Hilaira Simon, 1884, is here revalidated based on the structure of the copulatory organs and somatic characters. The composition of the genus corresponds in general to the glacialis species-group sensu Eskov (1981), and comprises six species transferred from Hilaira: Arctilaira banini (Marusik et Tanasevitch, 2003), A. gertschi (Holm, 1960), A. glacialis (Thorell, 1871), A. jamalensis (Eskov, 1981), A. nivalis (Holm, 1937), and A. vexatrix (O. Pickard-Cambridge, 1877), all comb.n. The genus shows a Holarctic distributional pattern: four species, A. gertschi, A. glacialis, A. nivalis, and A. vexatrix, are restricted to the tundra zone, while A. jamalensis inhabiting the Siberian boreal zone, and A. banini is known only from the highlands of Mongolia. The A. banini – A. jamalensis pair of species is probably a result of recent species differentiation during the Pleistocene glaciations. In this study, we provide a concise taxonomic history of genus Hilaira, an updated diagnosis for Arctilaira and detailed illustrations of male palp and epigyne for both the type species H. excisa (O. Pickard-Cambridge, 1871) and all Arctilaira species.
KEY WORDS: Araneae, taxonomy, dwarf-spiders, Erigoninae, new combination, Holarctic.