Pedro Castanheira

We revised the orb-weaving spider genus Carepalxis L. Koch, 1872 and tested its monophyly using Maximum Likelihood and Bayesian Inference phylogenetic analyses, comparing our results to a previously published family-level dataset on world-wide Araneidae. We studied the placement of the genus and the classification of the informally termed clade ‘backobourkiines’ using phylogenetic analyses based on two mitochondrial genes, cytochrome c oxidase subunit 1 (COI) and 16S rRNA (16S), and two nuclear genes, 28S rRNA (28S) and 18S rRNA (18S). Approximately 12,000 araneid records (vials) from major Australian and overseas collections were examined during our taxonomic revision. All phylogenetic analyses supported a monophyletic ‘backobourkiines’ clade, but found a polyphyletic Carepalxis, with its Australasian representatives being part of the ‘backobourkiines’ and the Neotropical species being related to the Neotropical Ocrepeira Marx, 1883. Consequently, the genus was revised to include seven endemic Australian species, Carepalxis montifera L. Koch, 1872 (type species), C. bilobata Keyserling, 1886, C. ferreirasousai sp. nov., C. kolla sp. nov., C. megalostylus sp. nov., C. tholos sp. nov. and C. tuberculata Keyserling, 1886 (=C. furcifera (Keyserling, 1886) syn. nov.), in addition to C. beelzebub (van Hasselt, 1873) (=C. suberosa Thorell, 1881 syn. nov. = C. tuberculifera (Thorell, 1881) comb. nov., syn. nov. = C. tricuspidata Chrysanthus, 1961 syn. nov.), which is present in Australia, Indonesia (West Papua) and Papua New Guinea. The following new combinations for Neotropical species previously placed in Carepalxis were proposed: Ocrepeira camelus (Simon, 1895) comb. nov., Ocrepeira gibbosa (O. Pickard-Cambridge, 1889) comb. nov., Ocrepeira perpera (Petrunkevitch, 1911) comb. nov., Ocrepeira quasimodo (Ferreira-Sousa & Motta, 2022) comb. nov., and Ocrepeira topazio (Ferreira-Sousa & Motta, 2022) comb. nov. Within the backobourkiines, Carepalxis can be recognised by the presence of two cephalic humps in females and two enlarged megaspines apically on tibia II of males (both here considered synapomorphies of the genus), an anteriorly elevated abdomen usually with numerous tubercles, humps or sigilla in addition to the humeral humps, an elongated male pedipalp median apophysis bearing a small projection, and a female epigyne with broad lateral lobes, and, whenever present, conspicuous transverse slits instead of baso-lateral flaps. ZooBank: urn:lsid:zoobank.org:pub:4F888132-4EE9-417F-9A82-7F9C470C9FB3

Among terrestrial animals, spiders exhibit the most striking examples of sexual size dimorphism (SSD) but better understanding of its evolution requires improved taxonomy and phylogeny. Many sexually dimorphic spiders lack adequate description, phylogenetic placement, and natural history observations. In South Africa, we documented the natural history of a poorly known spider, Megaraneus gabonensis (Lucas, 1858), with extreme, female-biased SSD (eSSD, female:male approximately 4:1). Here, we redescribe M. gabonensis, place Megaraneus Lawrence, 1968 phylogenetically for the first time, assess whether the observed eSSD represents an independent evolutionary origin, and test whether the macroevolutionary pattern is better explained by male dwarfism or female gigantism. The recovered phylogenetic placement of Megaraneus in the araneid 'backobourkiines', a clade previously considered as restricted to East Asia and Australasia, extends the range of this clade to the Afrotropics. We find that eSSD was present in the common ancestor of the 'backobourkiines', with further increases in female body length occurring independently in Megaraneus, Backobourkia Framenau, Dup & eacute;rr & eacute;, Blackledge & Vink, 2010, and the currently misplaced Parawixia dehaani (Doleschall, 1859). We conclude that the evolution of eSSD reflects a complex pattern of sex-specific size changes across spider phylogeny, but that in Megaraneus it results from female gigantism.

Ten new species of the orb-weaving spider genus Alpaida O. Pickard-Cambridge, 1889 are described from Espírito Santo, Minas Gerais, and Rio de Janeiro states, Brazil: Alpaida batman sp. nov., A. capixaba sp. nov., A. linhares sp. nov., and A. sooretama sp. nov. come from Sooretama and Linhares (Espírito Santo state), while A. jequitiba sp. nov. from Parque Estadual dos Três Picos (Cachoeiras de Macacu), A. coati sp. nov. and A. serrana sp. nov., both from Parque Nacional da Serra dos Órgãos (Teresópolis), A. regua sp. nov. from Reserva Ecológica de Guapiaçu (REGUA, Cachoeiras de Macacu), and A. taquara from Parque Estadual da Pedra Branca (PEPB) and Ilha do Fundão (both Rio de Janeiro city), are all from Rio de Janeiro state. Alpaida pretiosa sp. nov. is found in all three states: Sooretama and Linhares (Espírito Santo state), Reserva União (Cachoeiras de Macacu, Rio de Janeiro state), and in Viçosa (Minas Gerais state). Additionally, we correct the mismatching of one of our males with females of another species from the literature, and expand the distribution of A. mendensis Baptista, Castanheira & Prado, 2018.

The male of Socca australis Framenau, Castanheira & Vink, 2022 is described for the first time based on a specimen collected in a campsite near the Fitzgerald River National Park in Western Australia. New distribution records are given for two species expanding their known distribution into additional states, S. caiguna Framenau, Castanheira & Vink, 2022 (previously known from Western Australia only, now also South Australia) and S. levyashini Framenau, Castanheira & Vink, 2022 (previously Victoria only, now also Queensland).

A new species of Harmonicon F. O. Pickard-Cambridge, 1896, is described from the Cerrado biome in Central-West Brazil, representing the first non-Amazonian and the southernmost record for the genus. Furthermore, we present a new diagnosis of the genus, expanding its original diagnosis, and redescribe its type species, Harmonicon rufescens F. O. Pickard-Cambridge, 1896, based on an adult female specimen from the same biogeographical area of its type locality.

A new species of Dipluridae Simon 1889, Linothele darien n. sp., is described from Panama. This is the first Linothele Karsch 1879 species described for the continental part of Central America and the second outside South America. Linothele darien n. sp. is compared to L. megatheloides Paz & Raven 1990 and L. sericata (Karsch 1879), two similar species from Colombia. Also, a discussion about the specimens from Panama studied and identified as L. megatheloides by N. Paz is included.

A new species of the lyrate curtain-web spider genus Trechona C. L. Koch, 1850, Trechona minuana sp. nov., is described, based on males and females from Santa Catarina state, South Brazil. It is the first species of the genus from this Brazilian region. Additionally, we describe for the first time the female of Trechona excursora Pedroso, Miranda & Baptista, 2019 based on specimens from its type localities.

A new Brazilian genus of curtain-web spiders, family Dipluridae Simon, 1889, Harpathele gen. nov., is described, with Harpathele gymnognatha comb. nov. (Bertkau, 1880) (Rio de Janeiro state) as its type species. The new genus is a lyrate Diplurinae and it is known only from southeast Brazil. It may be recognized by the relatively small body, maxilla with dorsal transverse suture showing distinct curve at its basal third, a field of numerous long and thin setae above that suture, and a field of small rigid bristles below it, among other characters. Harpathele gymnognatha comb. nov. (Bertkau, 1880) is revalidated and redescribed, with the designation of a neotype and the first description of a male, based on specimens collected in its type locality that match the original description and illustrations, and is pointed as senior synonym of Diplura annectens (Bertkau, 1880). Additionally, two species of the new genus are described: Harpathele cariacica sp. nov., based on females from Espírito Santo state, and Harpathele salinas sp. nov., based on males from Rio de Janeiro state.

A new monotypic Australian genus in the orb-weaving spider family Araneidae Clerck, 1757 is described, Venomius gen. nov., with V. tomhardyi sp. nov. as type species. Somatically, Venomius gen. nov. is similar to the typical leaf-curling orb-weaving spiders, such as Phonognatha Simon, 1894 or Leviana Framenau & Kuntner, 2022, due to a similar elongate cylindrical abdomen and colouration; however, the genital morphology of the new genus is very different. Most unusual are the presence of two strong macrosetae on the male pedipalp tibia. Male pedipalp sclerites are complex, with diagnostic characters including the tibial macrosetae and a keeled median and a rounded basal process on the stipes. The epigyne of females is wholly covered by the scape that has a short median process. Venomius tomhardyi gen. nov. et sp. nov. has been collected in southern Australia, from Tasmania to Western Australia, where it builds a circular, vertical orb-web. Spiders often hide in silk-lined hollows in branches of trees when disturbed during the day.

A key to the six Australian genera of the wolf spider (Lycosidae Sundevall, 1833) subfamily Artoriinae Framenau, 2007 is provided, now including Artoria Thorell, 1877, Artoriopsis Framenau, 2007, Diahogna Roewer, 1960, Kangarosa Framenau, 2010, Kochosa gen. nov. and Tetralycosa Roewer, 1960. Kochosa gen. nov. is described to include 16 species: K. australia sp. nov. (type species; from New South Wales, Queensland, South Australia, Victoria, Western Australia), K. aero sp. nov. (Western Australia), K. asterix sp. nov. (New South Wales, Queensland, Tasmania and Victoria), K. confusa sp. nov. (Queensland), K. erratum sp. nov. (Queensland), K. fleurae sp. nov. (Victoria), K. mendum sp. nov. (Australian Capital Territory, New South Wales, Queensland), K. nigra sp. nov. (Queensland), K. obelix sp. nov. (Western Australia), K. queenslandica sp. nov. (Queensland), K. sharae sp. nov. (South Australia), K. tanakai sp. nov. (New South Wales, Queensland), K. tasmaniensis sp. nov. (Tasmania), K. timwintoni sp. nov. (Western Australia), K. tongiorgii sp. nov., (Queensland), and K. westralia sp. nov. (Western Australia). Kochosa gen. nov. differs distinctly from all other genera within the Artoriinae by somatic and genitalic morphology. Most conspicuous is a distinct off-white or yellowish-white cardiac mark on an otherwise generally uniformly dark abdomen. The cardiac mark is rendered by thick black setae, which are particularly dense posteriorly. The tegular apophysis of the male pedipalp is heavily reduced, generally forming a semi-transparent small lobe. In turn, the embolic division is often complex with a variety of apophyses. Kochosa gen. nov. generally inhabit mesic habitats such as temperate and tropical shrubs and forests along the eastern and south-eastern coast and in the south-western parts of Australia.