Taxonomic revision of the Neotropical spiders of the genus Idiops Perty, 1833 (Araneae, Idiopidae), with description of four new species

Abstract

Neotropical species of the genus Idiops Perty, 1833 are reviewed, and four new species are described from Brazil: I. duocordibus Fonseca-Ferreira, Guadanucci & Brescovit sp. nov., I. guri Fonseca-Ferreira, Guadanucci & Brescovit sp. nov., I. mocambo Fonseca-Ferreira, Guadanucci & Brescovit sp. nov. and I. sertania Fonseca-Ferreira, Guadanucci & Brescovit sp. nov. The majority of species are redescribed based on the examination of the types and extensive material. Males of I. petiti (Guérin, 1838), I. rastratus (Pickard-Cambrige, 1889), I. rohdei Karsch, 1886 and I. nilopolensis Mello-Leitão, 1923, and females of I. fuscus Perty, 1833 and I. pirassununguensis Fukami & Lucas, 2005, hitherto unknown, are described for the first time. Idiops nilopolensis, considered a nomen dubium, is revalidated. Idiops fulvipes Simon, 1889 is synonymized with I. argus Simon, 1889, and I. santaremius (Pickard-Cambrige, 1896) is synonymized with I. petiti. Neotypes are designated for Idiops fuscus, I. nilopolensis and I. siolii (Bücherl, 1953). Idiops bonapartei Hasselt, 1888 is considered species inquirendae, since the type is an immature female. Finally, an updated distribution map of Neotropical species is included. The genus now has 24 species in the Neotropical region.

Morphometric Analysis of a Trapdoor Spider (Araneae, Idiopidae) across Different Brazilian Biomes Reveals the Geographic Variation of Spiders from the Caatinga Biome

“…The current distribution of I. pirassununguensis over a large geographic area shows an unusual pattern that is distinct from that observed for other trapdoor spider species, which, in general, have a restricted range and strong geographic and genetic structuring, as observed, for example, in spiders from the families Euctenizidae [30,41,78], Antrodiaetidae [42,79,80], Migidae [43,81,82], Halonoproctidae [83], and even Idiopidae [84]. It is remarkable that, even though I. pirassununguensis has a wide distribution across different biomes and presents significant variation in relation to the size and shape of non-sexual structures, the specimens share a series of diagnostic sexual characteristics for the species, related to the copulatory bulb, pedipalp, and tibial apophysis [46]. This finding supports the hypothesis that, based on various species of insects and spiders [85], male genitalia show less variation than other body parts, indicating a case of intraspecific variation.…”

“…For the morphometric analysis, we selected 64 specimens of I. pirassununguensis, previously identified during the review of neotropical species of the genus Idiops [46]. Only males were used in the analysis, as they represent more than 90% of the material available for examination.…”

“…Here, through a broad analysis based on linear and geometric morphometric methods, we investigated the patterns of geographic variation of the trapdoor spiders of the species Idiops pirassununguensis Fukami and Lucas, 2008 (Idiopidae). The sampled populations are from different biomes in Brazil, including a tropical rainforest (Amazon), a savanna (Cerrado), and a seasonally dry tropical forest (Caatinga) [46].…”

Idiopidae Simon, 1889 in the Brazilian Amazon: two new species and a new geographic record

“…All measurements are expressed in millimeters (MM). The terminologies used are based on Rossi et al (2021), andFonseca-Ferreira et al (2021). Photographs and measurements were taken using a Leica M205C stereomicroscope and the Leica Application Suite version 4.10.0.…”

“…Despite being highly diverse and found in virtually every part of the globe, the Idiopidae family still requires further studies focused on taxonomy, biogeography, and ecology. This need is particularly pronounced in the Amazon region, especially in Brazil, where only seven species of Idiops and two of Neocteniza have been recorded, still being the least sampled region compared to other Brazilian states (Fonseca-Ferreira et al 2021;Rossi et al 2021). Many areas in Brazil remain undersampled, and as a result, the actual distribution of the family in the country is not well understood (Fonseca-Ferreira et al 2021;Rossi et al 2021).…”