Species richness of arachnids associated with Protea nitida (Proteaceae) in the Cape fynbos.

Regular counts of Arachnida on Protea nitida Mill. were made in three study areas in the western Cape over a period of one year. They were also investigated in the rest of the natural distribution area of P. nitida in the southern and western Cape. Collections were made according to three standardized methods. Five arachnid orders were collected, of which the Araneae (spiders) were dominant. Thirty-two spider species (653 individuals) representing 18 families were collected, of which five families and eight genera (eight species) were recorded for the first time on the Proteaceae in the Cape fynbos. Four non-Araneae orders were collected. A microhabitat preference was observed in some families. Numbers of immature spiders peaked in autumn. Adults and immatures did not always have the same habitat distribution and did not always peak during the same season. Families also showed differences in seasonal abundance. Plant architecture and distribution influenced the number of species collected. Protea nitida hosted more spider species than less complex plants with smaller distributions. The implications of these findings are discussed in terms of biodiversity and invertebrate conservation.     

Distribution of Dermatophagoides mite (Acari: Pyroglyphidae) antigens in homes of allergic patients in Japan

Dust samples collected in 61 homes of patients with mite allergies and 11 homes of non-allergic people as controls were examined for antigen levels of Dermatophagoides farinae Hughes and Dermatophagoides pteronyssinus (Trouessart) to reveal the current distribution of allergenic mites in homes in Japan. Patient homes had higher antigen levels than control homes in comforters and pillows but not in futons, earpets, tatamis and wooden floors. Samples with antigen levels of 10 g m^-2 were more frequent in and around summer (approximately April-October) than other seasons of the year in most materials and the differences between patient and control homes in comforters and pillows observed in yearly totals was also observed during this period. Wooden structures showed higher antigen levels than concrete structures in comforters, futons, pillows, carpets and tatamis in patient homes. Mite contamination in patient homes in relation to environmental factors was discussed.     

我国捕鸟蛛两种雄蛛的描述(蛛形纲,蜘蛛目)

中国捕鸟蛛科2)过去记述5种.除虎纹捕鸟蛛Ornithoctonus huwena外,其它4种均为单性描述.经补充采集,发现了广西近捕鸟蛛Plesiophrictus guangxiensis Yin et Tan,2000和海南捕鸟蛛Selenocosmia hainana Liang,Peng,Wang et Chen,1999的雄性个体.补充描述如下.标本保存在湖南师范大学生命科学学院,文中量度单位均为mm.     

Venom apparatus of the Brazilian tarantula <Emphasis Type="Italic">Vitalius dubius</Emphasis> Mello-Leitão 1923 (Theraphosidae)

Tarantula venoms are a cocktail of proteins and peptides that have been increasingly studied in recent years. In contrast, less attention has been given to analyzing the structure of the paired cephalic glands that produce the venom. We have used light, electron, and confocal microscopy to study the organization and structure of the venom gland of the Brazilian tarantula Vitalius dubius. The chelicerae are hairy chitinous structures, each with a single curved hollow fang that opens via an orifice on the anterior surface. Internally, each chelicera contains striated muscle fiber bundles that control fang extension and retraction, and a cylindrical conical venom gland surrounded by a thick well-developed layer of obliquely arranged muscle fibers. Light microscopy of longitudinal and transverse sections showed that the gland secretory epithelium consists of a sponge-like network of slender epithelial cell processes with numerous bridges and interconnections that form lacunae containing secretion. This secretory epithelium is supported by a basement membrane containing elastic fibers. The entire epithelial structure of the venom-secreting cells is reinforced by a dense network of F-actin intermediate filaments, as shown by staining with phalloidin. Neural elements (axons and acetylcholinesterase activity) are also associated with the venom gland. Transmission electron microscopy of the epithelium revealed an ultrastructure typical of secretory cells, including abundant rough and smooth endoplasmic reticulum, an extensive Golgi apparatus, and numerous mitochondria.     

Biogeography of the world: a case study from cyphophthalmid Opiliones, a globally distributed group of arachnids

Aim To test the hypothesis that continental drift drives diversification of organisms through vicariance, we selected a group of primitive arachnids which originated before the break‐up of Pangaea and currently inhabits all major landmasses with the exception of Antarctica, but lacks the ability to disperse across oceanic barriers. Location Major continental temperate to tropical landmasses (North America, South America, Eurasia, Africa, Australia) and continental islands (Bioko, Borneo, Japan, Java, New Caledonia, New Guinea, New Zealand, Sri Lanka, Sulawesi, Sumatra). Methods Five kb of sequence data from five gene regions for more than 100 cyphophthalmid exemplars were analysed phylogenetically using different methods, including direct optimization under parsimony and maximum likelihood under a broad set of analytical parameters. We also used geological calibration points to estimate gross phylogenetic time divergences. Results Our analyses show that all families except the Laurasian Sironidae are monophyletic and adhere to clear biogeographical patterns. Pettalidae is restricted to temperate Gondwana, Neogoveidae to tropical Gondwana, Stylocellidae to Southeast Asia, and Troglosironidae to New Caledonia. Relationships between the families inhabiting these landmasses indicate that New Caledonia is related to tropical Gondwana instead of to the Australian portion of temperate Gondwana. The results also concur with a Gondwanan origin of Florida, as supported by modern geological data. Main conclusions By studying a group of organisms with not only an ancient origin, low vagility and restricted habitats, but also a present global distribution, we have been able to test biogeographical hypotheses at a scale rarely attempted. Our results strongly support the presence of a circum‐Antarctic clade of formerly temperate Gondwanan species, a clade restricted to tropical Gondwana and a Southeast Asian clade that originated from a series of early Gondwanan terranes that rifted off northwards from the Devonian to the Triassic and accreted to tropical Laurasia. The relationships among the Laurasian species remain more obscure.     

Biodiversity and origin of the non-flying terrestrial arthropods of Henderson Island

Henderson Island, a raised coral island on the extreme south-easterly edge of the Indo-Pacific plate, is of great importance as one of the few examples of a Pacific island with intact lowland forest. It is also of biogeographic interest as it is practically the final island in a series of island chains, along which the fauna of Polynesia has colonized, reaching back to New Guinea. New collections of the non-flying terrestrial arthropod fauna were made on Henderson Island in 1991. In excess of 100 taxa are now known. There is a rich mite fauna (especially oribatids), with many apparently endemic, some 26 species of spider, and nine species of isopod (including three endemic to Henderson or nearby Ducie Atoll). In addition Diplopoda, Chilopoda, Amphipoda, Pseudoscorpiones, Diplura, Protura and Collembola are represented. The majority of the fauna is derived from the west, as expected, though many taxa appear to be introduced, some of them from the neotropics (e.g. Frigga crocuta and perhaps Hoplophorella stilifer).