We surveyed the populations of spiders and their prey insects in a paddy field under sustainable cultivation in Aso, Kumamoto Prefecture in 2001 and 2003. Dominant species of spiders were Pardosa pseudoannulata, Tetragnatha sp. (certainly T. maxillosa) and Clubiona kurilensis and dominant prey insects included a non-pest, i.e. chironomids, and rice pests, i.e. Sogatella furcifera and Nephotettix cincticeps. We investigated the spatial distribution of the dominant species involving the vertical distribution on rice plants and the horizontal distribution within a paddy field. Sogatella furcifera and C. kurilensis were mostly located at lower parts of rice plants, 0-10 cm high, and sometimes at the upper parts. Pardosa pseudoannulata inhabited significantly lower parts, 0 and 0-5 cm, than the two species. On the other hand, N. cincticeps was observed from lower to upper parts. We surveyed the number of spiders and prey insects in 26 quadrats of 1 × 1 m and analyzed the degree of spatial overlapping between them using the Iwao's (1977) ω index. High values of ω were obtained between all spiders and chironomids and between C. kurilensis and S. furcifera. These results suggest that chironomids are important prey for spiders and C. kurilensis is an effective predator of rice planthoppers though this spider has not been regarded as an important predator.
Six species of the genus Otacilia are reported from Japan. A new species is described from Okinoerabu-jima Island, Kagoshima Prefecture, southwest Japan under the name of Otacilia stella. Three species, Otacilia komurai (Yaginuma 1952), O. taiwanica (Hayashi & Yoshida 1993) and O. vulpes (Kamura 2001) are transferred from the genus Phrurolithus. Although the genus Otacilia has been placed under Liocranidae, it is treated under Corinnidae in this study.
The family Paracortinidae Wang & Zhang 1993, comprising eleven species from southern China as well as Vietnam, is reviewed. Two new cave-dwelling species, Paracortina chinensis sp. n., from Yunnan Province, China, and P. multisegmentata sp. n., from Thanh Hoa Province, Vietnam, are described. The new discoveries permit a reconsideration of some characters applied in the systematics of the family. The monotypic genus Scotopetalum Shear 2000, with S. warreni Shear 2000, so far known only from two caves near Hanoi, Vietnam, and the apparently polytypic (sub) genera Altum Wang & Zhang 1993 and Relictus Wang & Zhang 1993, are synonymised under Paracortina Wang & Zhang 1993 (s. str.), all syn. n. A distribution map of, and a key to all hitherto described paracortinid millipedes are also provided.
Spiders of the families Thomisidae and Philodromidae (Arachnida, Araneae) mainly collected in the mountainous areas of Iran in 1978 are taxonomically studied and classified into 21 species of 10 genera. Most species are illustrated and described on the basis of the present specimens. Except for only two species, Xysticus kulczynskii Wierzbicki 1902 and Synaema globosum (Fabricius 1775), already known from this country, 19 species are new records to the Iranian fauna. Of these, 14 species, Tmarus stellio Simon 1875, Xysticus ninnii Thorell 1872 (subsp. fusciventris Crome 1965), X. cristatus (Clerck 1758), X. kochi Thorell 1872, X. gallicus Simon 1875, Oxyptila nigrita Thorell 1875, Heriaeus spinipalpus Loerbroks 1983, Misumena vatia (Clerck 1758), Pistius truncatus (Pallas 1772), Runcinia lateralis (C. L. Koch 1838), Thomisus hilarulus Simon 1875, Philodromus longipalpis Simon 1870, P. cespitum (Walckenaer 1802), and P. emarginatus (Schrank 1803), are previously known to science, while five species are regarded as new and described under the names Xysticus marusiki, X. logunovi, X. pieperi, Oxyptila makidica, and O. lutosa.
A new case of Caucaso-Far East disjunction was found in the spiders Yaginumena maculosa (Yoshida & Ono 2000), which is known from Caucasus and Japan. Ten other similar ranges in spiders are surveyed. The previously unknown female of Y. maculosa is described and the male is redescribed and illustrated.
Five new species, Cybaeus bitchuensis, C. daisen, C. mimasaka, C. momotaro, and C. tajimaensis, from eastern part of the Chugoku District consisting of Okayama, Tottori and Hyogo Prefectures, western Honshu, Japan, are described under the kuramotoi-group in the genus Cybaeus (Cybaeidae). The kuramotoi-group is medium in size and characterized by presence of the copulatory plug. Geographic distributions of the five species belonging to the kuramotoi-group and C. ashikitaensis, a species closely related to the group, are shown. Their ranges are parapatric one another except for some cases of partial overlap.
A wolf spider, Alopecosa volubilis Yoo, Kim & Tanaka 2004 is newly recorded from Japan based on specimens recently collected from Hokkaido by pit fall trapping. This species is redescribed with illustrations of its male palpal organs and female genitalia.
Collecting data newly obtained of two Japanese species belonging to the family Theridiidae, Robertus nojimai Yoshida 2002 and R. ogatai Yoshida 1995, are presented. Robertus yasudai Yoshida 2001 is newly synonymized with Leptorhoptrum robustum (Westring 1851) belonging to Linyphiidae.
The Japanese spiders of the genus Tylorida is revised. T. magniventer Bösenberg & Strand 1906 is newly synonymized with T. striata (Thorell 1877). T. ventralis (Thorell 1877) is a new record for Japan, although whether or not it is an indigenous species remains unclear.