Olios

Abstract: In the vast majority of spider species studied to date, the karyotype is homogeneous in morphology and exclusively telocentric. The sex-determining system consists of one to three X chromosomes in the male and, correspondingly, two to six in the female. This is the case in species of huntsman spiders belonging to the genera Heteropoda (2n=40+3X), Isopoda, Olios, and Pediana (2n=40+3X) and some populations of the colonial species Delena cancerides (2n=40+3X). In other populations of D. cancerides, wholesale fusion of the karyotype has occurred, reducing the standard huntsman karyotype of 43 telocentric chromosomes to 21 metacentrics and 1 telocentric. Eight of the centric fusion products, including an X-autosome fusion, are maintained in the heterozygous condition in males and, with the single telocentric, form a chain of nine chromosomes at meiosis. The two complexes comprising the chain behave as neo-X and neo-Y chromosomes, and thus the ancestral X1X2X3♂∶X1X1X2X2X3X3♀ sex-determining system has been converted to a system of six X and four Y chromosomes in the male and twelve X chromosomes in the female. Since sex-linked complex heterozygosity is also found in a number of species of social termites, it is suggested that such heterozygosity may have adaptive significance for a colonial lifestyle. Breakdown products of the chain of nine are present in specimens of D. cancerides from Canberra and these appear to represent hybrid products between the 2n=22 and 2n=43 forms. Hybridisation may also have been involved in the origin of the chain-forming races.

Abstract: Spiders from Laos collected on expeditions from 2003 to 2008 are investigated. Currently, 89 spider species are recorded from Laos. Records of 51 species are included in the present paper. Four species are described for the first time: Argiope dang sp. n. (male, female) from Vang Vieng, Pseudopoda wang sp. n. (male, female) from Nam Khan valley, Olios muang sp. n. (male) from Ban Thathot, and Thelcticopis folia sp. n. (female) from Nam Khan valley. Sixteen species are recorded from Laos for the first time: Acusilas malaccensis Murphy & Murphy 1983, Agelena limbata Thorell 1897, Anepsion maritatum (O. Pickard-Cambridge 1877, Arachnura melanura Simon 1867, Araneus ellipticus (Tikader & Bal 1981), Argiope pulchella Thorell 1881, Eriovixia pseudocentrodes (Bosenberg & Strand 1906), Hersilia flagellifera Baehr & Baehr 1993, Menemerus bivittatus (Dufour 1831), Myrmarachne turriformis Badcock 1918, Oxyopes birmanicus Thorell 1887, Portia assamensis Wanless 1978, Tetragnatha ceylonica O. Pickard-Cambridge 1869, Tetragnatha lauta Yaginuma 1959, Tylorida striata (Thorell 1877), Tylorida ventralis (Thorell 1877). New observations on the biology of Eurychoera banna Zhang, Zhu & Song 2004 are documented. E. quadrimaculata Thorell 1897 is firstly recorded from Brunei. The following species are transferred from the genus Zygiella (Araneidae) to the genus Guizygiella (Tetragnathidae): Guizygiella indica (Tikader & Bal 1980) comb. nov., Guizygiella shivui (Patel & Reddy 1990) comb. nov. Illustrations are given for Argiope pulchella, A. ?versicolor, Eriovixia pseudocentrodes, Laoponia saetosa Platnick & Jagerger 2008, Orsinome vethi (Hasselt 1882), Oxyopes birmanicus, Tylorida ventralis, mostly showing intraspecific variation. A map of Laotian collecting localities is given. Orsinome vethi is recorded for Flores the first time, the record represents the eastern most distribution of this species.

Abstract: An overview on the systematics of the stone huntsman spider genus Eusparassus Simon, 1903 and an identification key to the known species are presented. Six species-groups are proposed: the walckenaeri group (3 species, Eastern Mediterranean to Arabia and parts of North-Eastern Africa), dufouri group (8 species, Iberian Peninsula to parts of North-western Africa), vestigator group (3 species, Central to Eastern Africa and an isolated area in India), jaegeri group (4 species, Southern and South-Eastern Africa), tuckeri group (2 species, South-Western Africa) and doriae group (7 species, Middle East to Central and South Asia). Two species, E. pontii Caporiacco, 1935 and E. xerxes (Pocock, 1901) could not be placed in any of the above groups. The species from Africa and Arabia are revised. The following ten species are re-described: Eusparassus barbarus (Lucas, 1846), E. atlanticus Simon, 1909 stat. nov., E. syrticus Simon, 1909, E. oraniensis (Lucas, 1846), E. letourneuxi (Simon, 1874), E. fritschi (Koch, 1873) stat. rev., E. walckenaeri (Audouin, 1826), E. vestigator (Simon, 1897) comb. nov., E. laevatus (Simon, 1897) comb. nov. and E. tuckeri (Lawrence, 1927) comb. nov. The latter three species are transferred from Olios Walckenaer, 1837. Seven new species are described: Eusparassus arabicus spec. nov. (male, female) from Arabian Peninsula, E. educatus spec. nov. (male, female) from Namibia, E. reverentia spec. nov. (male, female) from Burkina Faso and Nigeria, E. jaegeri spec. nov. (male, female) from South Africa and Botswana, E. jocquei spec. nov. (male, female) from Zimbabwe, E. borakalalo spec. nov. (female) from South Africa and E. schoem-anae spec. nov. (male, female) from South Africa and Namibia. Three taxa, E. dufouri maximus Strand, 1906 syn. nov., E. rufobrunneus Caporiacco, 1941 syn. nov. and Olios furcatus Lawrence, 1927 syn. nov. are proposed as junior syn-onyms of E. oraniensis, E. vestigator comb. nov. and E. tuckeri comb. nov. respectively. Males of E. atlanticus stat. nov. and E. fritschi stat. rev. are described for the first time as in the female of E. vestigator comb. nov. Neotypes are desig-nated for E. barbarus, E. oraniensis and E. letourneuxi (all from Algeria). The male and female of Cercetius perezi Simon, 1902, which was known only from the immature holotype, are described here for the first time. This resulted in recogniz-ing the monotypic and little used generic name Cercetius Simon, 1902 as a synonym of the widely used name Eusparas-sus. Nearly all the species are illustrated for the first time. Eusparassus concolor Caporiacco, 1939 is transferred to Olios and the replacement name Olios quesitio is proposed because of secondary homonymy. For the majority of the species, new geographical records are presented. The systematics and zoogeography of the currently known species and species groups are discussed. A brief note on the copulation process of E. walckenaeri is presented.