Effects of ultraviolet rays and temperature upon drag lines of mature spider Argiope amoena were studied by the electron spin resonance ESR method. The relative signal intensity as a measure of decomposition of protein molecules increased at room temperature with irradiation time of ultraviolet rays. This shows that the protein molecules constituting drag lines were decomposed by the ultraviolet rays. The signal intensity without ultraviolet rays decreased gradually to 100°C, above 100°C increased, and then showed a peak at about 170°C. The peak may come from the superposition of two factors such as an increase in radicals ascribed to chemical decomposition at high temperatures and a decrease in radicals ascribed to the enhancement of molecular motion of silk protein.

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Interspecific differences in diel activity and habitat preference of wolf spiders (Araneae: Lycosidae) were observed by pitfall trapping in a northwest area of Kanto Plain, Japan. Pardosa agraria, P.astrigera and P.graminea were all collected only in daytime, and Pirata yaginumai and Pirata piratoides showed slightly diurnal and nocturnal tendency, respectively. Arctosa fujiii, Pirata clercki, Pirata procurvus, Pirata tanakai, and Tricca japonica can be regarded as aperiodic. Lycosid habitats were classified by combining qualities or grades of three environmental elements of substratum (B, bare soil; L, live plants; D, dead plants), light condition (s, sunshine; d, dark or shade) and water condition (0, rain alone; 1, standing water; 2, running water). Though every lycosid species occurred in three or more habitat classes, and seldom on upper parts of live plants, the highest frequency was observed in Bs0 in Pardosa astrigera, Ls0 in Pardosa graminea and Trochosa ruricola, Ls1 in Pirata clercki, Ls2 in Pardosa agraria, Pirata piratoides and Pirata yaginumai, Ds0 in Pirata procurvus and Pirata tanakai, Ds1 in Arctosa ebicha and Tricca japonica, and in Dd0 in Arctosa fujiii. Other seven lycosid species (Alopecosa virgata, Arctosa depectinata, Arctosa subamylacea, Lycosa coelestis, Pardosa pseudoannulata, Pardosa yaginumai and Pirata subpiraticus) in the study area were not or seldom trapped because of their low mobility or low density at the trapping sites. Differences between stages or sexes were obscure both in diel activity and habitat preference.

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Dissoloncha superbus (HULL, 1918) is newly recorded from Japan. There is slight difference between the present materials and the British ones in the shape of dorsal setae and the surface ornamentation of ventrianal shield.

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A new species of the spider genus Heptathela belonging to the family Liphistiidae is described from Tam Dao, northern Vietnam under the name of Heptathela tomokunii sp. nov. The spiders of the species built retreats with a trapdoor typical for the Heptathelinae. A close relationship is recognized between this new species and Heptathela tonkinensis (BRISTOWE, 1933) described from the area of Song Luc Nam, about 100km east of the type locality of the new species.

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The male of Cyclosa angusta TANIKAWA, 1922 is described for the first time.

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The breeding and nymphal development of Lycosa coelestis L. KOCH were investigated by means of rearing under seminatural conditions. Three females successfully bred twice in their life. Breedings were carried out in underground nest. The mean number of progenies produced per female in each brood and its standard deviation were calculated to be 202.0±19.5 in the 1st brood and 76.7±25.5 in the 2nd. The mean total number of progenies produced per female in life was 278.7±35.3. The 2nd instar nymphs dispersed from mother's back on 19th July, 1995, developed to adult by late May-July of the next year. The number of molts required was 6-8 in the male and 7-9 in the female. Overwintering nymphs often dug underground nest and stayed in it.

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A comparative study was done on the morphology and distribution of two forms in Rhysotritia ardua (C. L. KOCH, 1841) in Japan. Compared with the form M (claws on legs I-IV: 1-1-1-1), the form BT (claws on legs I-IV: 2-3-3-3) showed larger body size, stouter body form, darker body color, thicker body setae, sensilli with stronger barbation and lamellar setae more closely situated to rostral setae. No segregation was found in horizontal as well as vertical distribution of these two forms and it suggests that they cannot be treated as separate subspecies. An appropriate decision on the taxonomical treatment of these two forms will be done after ecological and biochemical studies.

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The web structure of Wendilgarda sp. was one of the most unique types that had been known in spiders. This web was built above the stream and did not have radii and sticky spirals, but had some horizontal lines and sticky threads. The horizontal lines were non-sticky silks, slightly inclined, and attached directly to branches or rocks in the stream. The sticky threads were spun between the horizontal line and the water surface. Each end of these vertical sticky threads was connected with the surface of the water. The predatory behavior of this species was also observed. As soon as the prey struck sticky thread, the spider moved to the point above entangled prey along horizotal line, and reeled up the sticky thread with prey. After wrapping the prey with dry silks, she returned to the center of the web.
These observations suggested that Wendilgarda web did not resemble the ray-formed orb web of the genus Theridiosoma, but related to the other theridiosomatid spider: e.g. the genus Ogulnius.

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