The life history and reproductive activity of the Uloborid spider Octonoba sybotides were investigated. The seasonal change in the size distribution of the O. sybotides population at the study site showed that this spider has two generations per year: an overwintering generation and a summer generation. The overwintering generation hibernates from late November to early March as the juvenile stages. The duration of egg incubation varied greatly through the reproductive season, and seemed to be related to the total effective temperature. The number of eggs in each egg sac was significantly correlated with the weight of the mother. O. sybotides constructs a horizontal orb-web that frequently contains dimorphic stabilimenta (spiral and linear). The weights and condition indices of spiders showed that the spiders on webs with spiral stabilimenta to be in poorer energetic condition than spiders on webs with linear stabilimenta. The proportion of spiders on webs with spiral stabilimenta was negatively correlated with the prey abundance in their environment. The frequencies of spiral and linear stabilimenta in a population seem to be influenced by prey abundance, and prey-limited conditions induce the majority of O. sybotides to construct webs with spiral stabilimenta.
Three Japanese spider species, which have been placed in the genus Zilla, are moved to the genus Eriophora, based on cladistic analysis. Three known species, Eriophora sagana (Bösenberg & Strand 1906) comb. nov., E. sachalinensis (S. Saito 1934) comb. nov., and E. aurea (S. Saito 1934) comb. nov. are redescribed and one new species, E. yanbaruensis sp. nov., is described from Okinawajima Island, Japan. On the other hand, Aranea sagana Bösenberg & Strand 1906 is revived from a homonym of Aranea sagana (Keyserling 1893). Eriophoramigra Zhu & Song 1994 is newly synonymized with Eriophora sagana (Bösenberg & Strand 1906) comb. nov. and Eriophora flava Zhu & Song 1994 is newly synonymized with Eriophorasachalinensis (S. Saito 1934) comb. nov.
A small troglobiontic coelotine spider is described under the name of Coelotestroglocaecus sp. n. found in limestone caves on Okinawa Island, Japan. This is the first record of an eyeless coelotine spider. Morphological description is given in comparison with a sympatric Coelotes okinawensis. Extensive field survey over the Ryukyu Islands showed that the new species is endemic to Okinawa Island, where it has been found rather widely but exclusively in limestone caves. The population density was extremely low, and the facts that only females have been collected and that they have extremely degenerated structures in epigynum projections and degenerated copulatory opening for coupling strongly suggest parthenogenetic reproduction. It has some additional morphological traits which seem adaptive to the life in the caves. Specialization to cave habitat is discussed in relation to the geological history of the Ryukyu Islands.
Four new species of the spider family Sparassidae are described from Japan under the names Olios japonicus sp. nov., Heteropoda simplex sp. nov., Sinopoda okinawana sp. nov. and S. tanikawai sp. nov. The genus Olios is recorded for the first time from Japan. Taxonomical notes and new records of some known species and comments on diagnostic characters of the subfamilies and genera of the Japanese Sparassidae are presented.
Two new genera of the subfamily Heteropodinae (Araneae: Sparassidae) are described from southern continental Asia: Pseudopoda gen. nov. and Bhutaniella gen. nov. Type species are designated and described: Pseudopoda prompta (O.P.-Cambridge 1885) COMB. NOV. and Bhutaniella hillyardi sp. nov. The following species, originally described as Heteropoda spp., are included in Pseudopoda gen. nov.: P. casaria (Simon 1897) COMB. NOV., P. exigua (Fox 1938) COMB. NOV., P. exiguoides (Song & Zhu 1999) COMB. NOV., P. grahami (Fox 1936) COMB. NOV., P. lushanensis (Wang 1990) COMB. NOV., P. virgata (Fox 1936) COMB. NOV., P. zhangmuensis (Hu & Li 1983) COMB. NOV., P. zhejiangensis (Zhang & Kim 1996) COMB. NOV. The following species, originally described as Heteropoda species, is included in Bhutaniella gen. nov: B. sikkimensis (Gravely 1931) COMB. NOV. Species of both genera seem to inhabit only higher altitudes (>1000 meter above sea-level).
Two opilionid species of Phalangiinae (Phalangiidae), Acanthomegabunus sibiricus n. gen. and n. sp., and Homolophus gobiensis n. sp. are described from southern Siberia, Russia, and Mongolia, respectively. A refined diagnosis of the genus Homolophus is presented. Phalangium pallens Kulczynski is resurrected and placed under Homolophus. Homolophuspotanini is removed from the genus and is placed provisionally in the genus Opilio. Opilioasiaticus Gricenko 1979 is first synonymized with Opilio potanini (Simon 1895).
Scleropilio insolens (Simon 1895) is redescribed based on the materials collected from southern Siberia, Russia. A total of six species are synonymized with Scleropilio insolens: four species of Scleropilio, S. coriaceus Roewer 1911, S. tibialis (Roewer 1956), S. diadema (Gricenko 1975), S. elenae (Gricenko 1975), Opilio armatus Roewer 1911, and Udezatusspinous Nakatsudi 1943. Ovipositor and seminal receptacle of the species are illustrated and described for the first time.
A lycosid spider, Pardosa okinawensis Tanaka 1985, which is distributed in the Southwest Islands (Okinawa Is., Kumejima Is., and Amami-Oshima Is.), Japan, was newly found to be a member of the genus Wadicosa Zyuzin. This species resembles Wadicosa venatrix from Europe and China but differs from it by having an embolus with non-twisted tip on the male palp.