Spiricoelotes zonatus (Peng & Wang 1997) originally described from Hunan Province, China is newly recorded in Japan, and described on the basis of the specimens collected from an artificial cave in Glover Garden, Nagasaki City, Nagasaki Prefecture. The spider is distributed in the eastern part of China and is regarded as a naturalized species in Japan, which was artificially introduced by ships from China.

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A new genus and species of Opilioninae (Phalangiidae), Redikorcevia platybunoides gen. & sp. n. is described from the mountains of Kazakhstan. A new tribe Scleropilionini trib. n. is established to encompass the new genus and Scleropilio Roewer.

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A new species of Cybaeus spiders collected from Mt. Odaesan, C. aratrum sp. nov., is described with detailed illustrations, leg spination, trichobothrium patterns and SEM photographs. This species can be distinguished from other Cybaeus species by male palpal conductor largely developed plow-like with twisted distal part, embolar tip injector-like, and patellar apophysis with 44 protuberances on the distal part. A key to the species of Korean cybaeid spiders is provided.

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A new harvestman species Homolophus azerbaijanicus from the Lenkoran zone of Azerbaijan is described and compared with its nearest relative - H. potanini (Simon 1895). The diagnosis of the genus Homolophus Banks 1893 is revised to allow its distinctiveness from Opilio Herbst 1798.

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Japanese spiders of the genus Dolomedes are revised and its phylogeny is inferred by mt-DNA. Dolomedes japonicus Bösenberg & Strand 1906 and D. angustivirgatus Kishida 1936 are removed from the synonymy. Dolomedes fimbriatoides Bösenberg & Strand 1906 and D. hinoi Kayashima 1952 are newly synonymized with D. sulfureus L. Koch 1878, and D. stellatus Kishida 1936 is synonimized with D. japonicus. Two new species, D. fontus and D. silvicola are described. Relative leg length and proportion of male palpal tibia are considered as good keys to indentify Dolomedes spiders, whose genital organs closely resemble one another. Dolomedes sulfureus and D. silvicola, often found on vegetation, have much longer legs and male palpal tibia than their relatives that inhabit near water and run on water surface or hide under water when disturbed. Molecular phylogenetic analysis using mt-COI revealed the following; ((((raptor, yawatai), japonica), orion), (((angustivirgatus, sulfureus), fontus), (silvicola, saganus)), horishanus).

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The genus Achaearanea Strand, 1929 (Theridiidae) is revised. Two genera, Henziectypus Archer, 1946 and Cryptachaea Archer, 1946, are revived from the synonymy of Achaearanea. Parasteatoda Archer, 1946 is recognized as an independent genus. Redefinitions and species lists of four genera, Achaearanea, Henziectypus, Cryptachaea and Parasteatoda, are given. Nine species of Henziectypus, 61 species of Cryptachaea, and 37 species and a subspecies of Parasteatoda, are respectively transferred from Achaearanea to the suitable genera.

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A new corinnid species is described from Japan under the name of Otacilia mustela. Specimens of the new species can be distinguished from those of O. vulpes (Kamura 2001) by their small and narrow retrolateral tibial apophysis in male palp, and relatively short and wide spermathecae in female internal genitalia.

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A new species Stenaelurillus abramovi sp.nov. is described from Vietnam.

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The jumping spider, Phidippus audax (Hentz), preys on other spiders both intra- (cannibalism) and inter-specifically (intraguild predation). Smaller individuals become the victims in these predations. One hypothesis for the evolution of IGP/cannibalism is that consuming other carnivores (e.g., spiders) decreases a dietary stoichiometric imbalance because carnivorous prey have higher nitrogen contents than herbivorous prey. This study examined whether the nitrogen content of prey affects growth patterns of spiders by using fruit flies whose nitrogen contents were artificially enhanced. Spiders that were raised on the nitrogen rich prey grew faster than those raised on unmanipulated prey, by shortening moulting intervals. This result is consistent with the stoichiometric argument and would also have important consequences to the community dynamics of these organisms, by altering the size structure of communities with IGP and cannibalism.

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This study examined geographic variation of adult body size and voltinism in the kleptoparasitic spider Argyrodes kumadai in three regions (Boso peninsula in Japan mainland, Amami-oshima Island, and Okinawa Islands) to see how climatic conditions and host use affect life history of this spider. Adult body size differed significantly between populations; Amami-oshima population was larger than the other populations. Voltinism also differed between populations; Boso population was univoltine, Amami-oshima population was probably univoltine with partial bivoltine, Okinawa population seemed to be bivoltine or multi-voltine. The variation of body size appeared to have been created by the combination of the differences in developmental period, food availability in different hosts, and voltinism.

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