Araneus rotundicornis Yaginuma (1972) (Araneae: Araneidae) new to Korean Spider Fauna

Araneus rotundicornis, which has been known as a species endemic to Japan, was caught in Mt. Weolaksan in Chungcheongbuk-do, Korea. And it is described and illustrated in this report.     

中国云南高黎贡山园蛛属4新种记述(蜘蛛目:园蛛科)

本文记述了采自中国云南高黎贡山的园蛛属Amneus 4新种:春林园蛛,新种Amneus chunlin sp.nov.,李氏园蛛,新种Araneusliae sp.nov.,丰盛园蛛,新种Amneua plenus sp.nov.和亚坪园蛛,新种Araneus yapingensis sp.nov..模式标本正模及部分副模保存于湖南师范大学(HNU),部分副模将保存于美国加州科学学院(CaAS).文中量度单位为mm.     

Selected aspects of spinning apparatus development in Araneus cavaticus (Araneae,Araneidae)

In the first half of this century, several workers observed small, seemingly glandular structures attached to the ampullate glands of spiders. Hence, they were termed accessory ampullate glands. In juvenile Araneus cavaticus, two pairs of these structures are present (starting at least with third instars), one pair attached to the major ampullate (MaA) glands and the other pair attached to the minor ampullate (MiA) glands. In adults, two pairs of accessory MaA glands and two pairs of accessory MiA glands are present. The two latter-formed pairs of accessory ampullate glands are clearly the remnants of those ampullate glands which atrophy shortly after adulthood is reached. Morphological similarities between these accessory ampullate glands and those present in juveniles provide an indication that the latter also have their origin in functional ampullate glands. A reduction in the number of ampullate glands following the last molt occurs in many spiders. The reason(s) for these reductions is unknown. In penultimate spiders close to ecdysis, we have observed that while the larger pairs of MaA and MiA glands (those that are retained in the adult) are undergoing molt-related changes which apparently render them nonfunctional, their smaller counterparts are seemingly unaffected and functional. This raises the possibility that the principal role of the smaller ampullate glands may be to assume functions during the pre-ecdysial period which are normally in the domain of the larger ampullate glands. If true, then their degeneration after the last molt would make economic sense. The presence of cylindrical spigots in juvenile females starting with fourth instars is documented.     

四种园蛛同工酶的比较研究

本文采用聚丙烯酰胺凝胶电泳的方法,对叶斑园蛛、角类肥蛛(黑、白2种体色)、大腹园蛛、黑斑园蛛4种园蛛科蜘蛛的酯酶(EST)同工酶、乳酸脱氢酶(LDH)同工酶、超氧化物歧化酶(SOD)同工酶进行了比较研究。结果表明,4种园蛛的EST、LDH具有明显的种族特异性,而SOD在种间基本没有差别。不同种蜘蛛都有各自的EST、LDH同工酶谱型,可以用它们作为识别物种的附加指标。     

Sublethal effects of two neurotoxican insecticides on Araneus pratensis (Araneae: Araneidae)

Spiders are important predators of several agricultural pests and they play an important role as indicators of ecosystem disturb. In Argentina, soybean crop has increased from the introduction of transgenic soybean resistant to glyphosate. This expansion produced an increase in the use of conventional and non-selective pesticides to control soybean pests. The objective of this work was to evaluate the side effects of subletal concentrations of two neurotoxican insecticides with a different mode of action: endosulfan (Glex, 35%, 25 mg/l a.i.) and spinosad (Tracer, 48%, 30 and 3 mg/l a.i) on Araneus pratensis. The insecticides were applied by ingestion of the treated prey (Musca domestica), and the effects on mortality, prey consumption, web building, mating, ootheca construction and fecundity were determined. Spinosad (30 mg/l a.i.) produced higher mortality than endosulfan (25 mg/l a.i.). Tremors and non-coordinated movements were observed in this treatment. The prey consumption was significantly reduced by the two insecticides (approximately 40% lower than control). The spider web building was significantly affected by the two insecticides, but spinosad had a greater effect. Though mating was not affected by both pesticides, abnormal oothecas and dehydrated eggs were observed. This work reports that sublethal concentrations representing approximately from 25 to 2.5% of the maximum field recommended concentrations (105 and 120 mg/l a.i., respectively) showed negative effects on A. pratensis. The consequences of these effects on role of A. pratensis as a natural mortality factor of soybean pests are discussed.     

The Spider Genera Singa and Hypsosinga (Araneae, Araneidae) in Israel

Israeli spiders of the orb-weaver genera Singa and Hypsosinga (Araneidae) have been revised. New and updated information on the little known Mediterranean spider fauna, pertaining to European species as well, is presented. Some of the species have never been adequately described or illustrated. All the species previously described from the Middle East and adjacent countries were re-examined. Aranea neta is newly placed in Singa and the following new synonyms are defined: Lithyphantes sepfemguffafus Simon, 1873, along with Araneus decorus (Simon, 1891) and Lithyphantes pollocki Denis, 1956 = Singa neta (O. P.-Cambridge, 1872); Singa afjinis O. P.-Cambridge, 1876 along with Singa attica Simon, 1884 = Hypsosinga albovittata (Westring, 1851). The presence of three species formerly reported from Israel, including one erroneously determined, has been confirmed, and the occurrence of another three species previously unknown from this country has been proved. All are newly described. Keys, detailed illustrations of diagnostic characters and records of -distribution are provided for each species.     

Elektronenmikroskopische untersuchungen an den Guanin-Speicherzellen von Araneus diadematus clerck (Araneae,Araneidae)

Zusammenfassung Bei einigen Spinnen, vor allem aus der Familie der Araneidae, bilden funktionell umgewandelte Mitteldarmzellen unmittelbar unter der Hypodermic eine nahezu geschlossene Zellschicht, die mehr oder minder stark mit Guaninkristallen angefiillt sein kann.Die distalen Zellbereiche dieser von uns als Guanocyten bezeichneten Zellen verzahnen rich mit der Hypodermis selbst oder stehen mit dem schmalen hypodermalen Hämolymphsinus in Verbindung. Thre proximalen Enden sind lang ausgezogen und schieben sich zwischen nicht umgewandelte Resorptionszellen. Jede Guanocyte steht mit dem Mitteldarmlumen in direkter Verbindung.Auf Grund des Organellenbestandes sind die Guanocyten als spezialisierte Mitteldarmzellen auzusprechen, die während der reproduktiven Periode die übrigen exkretorisch tätigen Gewebe bzw. Organe unterstützen oder ergänzen, indem sie der Hämolymphe, der Hypodermis und den benachbarten Resorptionszellen pinocytotisch purinhaltige Abbauprodukte und andere Exkrete entnehmen. Dieselben werden unter Mitwirkung eines glatten endoplasmatischen Retikulums umgebaut und temporär intrazellulär als kompliziert aufgebaute Kristalle innerhalb von membranösen Kristallsäckehen gespeichert.Die Notwendigkeit intrazellulärer Exkretspeicherung auf Grund der Ernährungs-physiologie und Abwandlungen in der Funktionsmorphologie sowie fortschreitender Alterungserscheinungen wird diskutiert.

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Electromicroscopic studies of the guanine storage cells of Araneus diadematus Clerck (Araneae, Araneidae)

Summary Guanocytes are present in several spiders especially of the family Araneidae. The guanocytes form a compact cell-layer under the hypodermis. Their distal parts remain connected to the hypodermic hemolymph sinus, while the proximal ends establish contact with the midgut lumen in the shape of a long cellular process.The organelle equipment of the guanocytes shows that they are specialized midgut cells. They support or replace the other excretory tissues and organs especially during the reproduction period. By pinocytosis, the guanocytes remove catabolites of the purine and protein metabolism from the hemolymph, the adjacent resorption cells of the midgut, as well as from the overlying hypodermis cells. The stored catabolites are formed into complex crystals assisted by the smooth endoplasmic reticulum.The necessity of the temporary intracellular excretory storage on the basis of the physiology of nutrition, changes in the functional morphology, and general signs of old age are discussed.

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Die Untersuchungen werden dankenswerterweise von der Deutschen Forschnungsgemeinschaft durch Sach- und Personalmittel gefördert.

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Herrn Prof. Dr. H.-U. Koecke danke ich für seine Unterstützung und die Einräumung eines Arbeitsplatzes am Elektronenmikroskop.     

Determinants of Mating Frequency in the Spiny Orbweaving Spider,Micrathena gracilis (Araneae: Araneidae)

Male Micrathena gracilis require two copulations, separated by a dismount, in order to inseminate both reproductive tracts of the female. We examined several factors that might influence a male's copulatory success. Web structure influenced male courtship and dismount tactics, but not copulatory frequency. The presence of another male reduced the likelihood of a given male copulating with both tracts, a limitation mediated by sexual responsiveness of the female. Mating status of the female did influence copulatory frequency; males were less likely to copulate a second time with nonvirgin females. In summary, males modify mating activities to reduce predation by females, to reduce intermale competition, and to avoid expending gametes when there is little chance of fertilization. Females influence males by predatory activities, mediated through web structure, and enhancing sperm competition among males.     

Matriphagy in the Spider Amaurobius ferox (Araneidae,Amaurobiidae): an Example of Mother-Offspring Interactions

In the spider Amaurobius ferox, the mothers are systematically devoured by their young at a fairly constant interval. Observation of broods maintained under normal conditions showed the cannibalistic processes to be achieved within a few hours, in the course of which mothers and offspring appeared to exchange stimulation. In particular, the mothers exhibited ‘solicitation’ behaviours which appeared to activate and synchronize the young. An experiment was carried out to specify the respective role played by the two parties of the dyad in this case of matriphagy. The female's attitude towards the young (‘solicitation’, tolerance or predatory response) appeared to depend on her reproductive state. The attitude of the young towards the female (cannibalism, attraction, or flight) was shown to depend on their stage of development, but also on the female's attitude. These results support the hypothesis that, in A. ferox, matriphagy is regulated by mother-offspring interactions. Such a mechanism could ensure precise tuning of matriphagy in relation to the requirements of the young, and a certain amount of flexibility in reproduction.     

High-Toughness Silk Produced by a Transgenic Silkworm Expressing Spider (Araneus ventricosus) Dragline Silk Protein

Spider dragline silk is a natural fiber that has excellent tensile properties; however, it is difficult to produce artificially as a long, strong fiber. Here, the spider (Araneus ventricosus) dragline protein gene was cloned and a transgenic silkworm was generated, that expressed the fusion protein of the fibroin heavy chain and spider dragline protein in cocoon silk. The spider silk protein content ranged from 0.37 to 0.61% w/w (1.4–2.4 mol%) native silkworm fibroin. Using a good silk-producing strain, C515, as the transgenic silkworm can make the raw silk from its cocoons for the first time. The tensile characteristics (toughness) of the raw silk improved by 53% after the introduction of spider dragline silk protein; the improvement depended on the quantity of the expressed spider dragline protein. To demonstrate the commercial feasibility for machine reeling, weaving, and sewing, we used the transgenic spider silk to weave a vest and scarf; this was the first application of spider silk fibers from transgenic silkworms.     

Immunoreactivity of Glutamic Acid Decarboxylase (GAD) Isoforms in the Central Nervous System of the Barn Spider,Araneus cavaticus

The γ‐aminobutyric acid (GABA) has long been considered as an inhibitory neurotransmitter in the central nervous system (CNS) of both vertebrates and arthropods. Since the glutamic acid decarboxylase (GAD) has a restricted tissue distribution and catalyzes the conversion of L‐glutamate to GABA, immunoreactivity of GAD isoforms can reveal distribution of GABAergic neurons in the CNS. In the CNS of the spider Araneus cavaticus, immunoreactivity of GAD isoforms can be detected in the optic lobes including neurons and neuropiles of the supraesophageal ganglia. Strong GAD‐like immunoreactive cell bodies are concentrated in two bilaterally symmetric cell clusters of the protocerebrum. Some intrinsic cell bodies near the central body also show strong immunoreactivity. However, the intrinsic nerve masses and some of the longitudinal and transverse tracts within the supraesophageal ganglion are only lightly labelled, and the fibers transverse the hemisphere and the central fibrous masses are not labelled. Among the three basic types of cell bodies surrounding the central body, several clusters of the Type‐C cells show strong GAD‐like immunoreactivity, however both of the Type‐A and Type‐B cells are not labelled at all.     

Spider (Araneus diadematus) cocoon silk: a case of non-periodic lattice crystals with a twist?

Transmission electron microscopy was used to investigate the supramolecular structure of Araneus diadematus (garden spider) cocoon silk. Electron diffraction patterns contain features which are consistent with the presence of non-periodic lattice crystals, i.e. highly frustrated crystalline regions as identified previously in the major ampullate silk (MAS, dragline) of Nephila clavipes spiders. The diffraction patterns further suggest that crystals in A. diadematus cocoon silk may be twisted parallel to the chain direction, offering a potential explanation for the lower tensile stiffness of this fibre relative to MAS.     

Lineage Range Estimation Method Reveals Fine-Scale Endemism Linked to Pleistocene Stability in Australian Rainforest Herpetofauna

Areas of suitable habitat for species and communities have arisen, shifted, and disappeared with Pleistocene climate cycles, and through this shifting landscape, current biodiversity has found paths to the present. Evolutionary refugia, areas of relative habitat stability in this shifting landscape, support persistence of lineages through time, and are thus crucial to the accumulation and maintenance of biodiversity. Areas of endemism are indicative of refugial areas where diversity has persisted, and endemism of intraspecific lineages in particular is strongly associated with late-Pleistocene habitat stability. However, it remains a challenge to consistently estimate the geographic ranges of intraspecific lineages and thus infer phylogeographic endemism, because spatial sampling for genetic analyses is typically sparse relative to species records. We present a novel technique to model the geographic distribution of intraspecific lineages, which is informed by the ecological niche of a species and known locations of its constituent lineages. Our approach allows for the effects of isolation by unsuitable habitat, and captures uncertainty in the extent of lineage ranges. Applying this method to the arc of rainforest areas spanning 3500 km in eastern Australia, we estimated lineage endemism for 53 species of rainforest dependent herpetofauna with available phylogeographic data. We related endemism to the stability of rainforest habitat over the past 120,000 years and identified distinct concentrations of lineage endemism that can be considered putative refugia. These areas of lineage endemism are strongly related to historical stability of rainforest habitat, after controlling for the effects of current environment. In fact, a dynamic stability model that allows movement to track suitable habitat over time was the most important factor in explaining current patterns of endemism. The techniques presented here provide an objective, practical method for estimating geographic ranges below the species level, and including them in spatial analyses of biodiversity.     

The Effect of Feeding History on Prey Capture Behaviour in the Orbweb Spider Argiope keyserlingi Karsch (Araneae: Araneidae)

The prey capture behaviour of the orb-web spider Argiope keyserlingi Karsch was examined experimentally by subjecting spiders to two different feeding regimes (food deprived and food satiated) and three types of prey: Drosophila, blowflies (Lucilia cuprina) and bees (Apis mellifera). The attack behaviour of the spiders was influenced by both their foraging history and the type of prey. Food deprived spiders attacked Drosophila and bees more frequently than food satiated spiders, and food satiated spiders travelled more slowly to any of the prey types than food deprived spiders. Furthermore, Drosophila were never wrapped in silk but only grasped with the chelicerae, whereas both blowflies and bees were always wrapped. This provides experimental confirmation that feeding history affects the decision of orb-web spiders to accept or reject any given prey.     

菜田蜘蛛群落组成及生态位分析

根据2006年5月至8月对蕃茄、茄子、豆角、青椒、尖椒及油菜共6种蔬菜田蜘蛛种类及数量的系统调查,经初步整理鉴定,隶属于9科19属27种。通过时空二维生态位分析,星豹蛛的二维宽度最大,草间钻头蛛和齿螯额角蛛的二维重叠值最大。应用模糊聚类法对群落的相似性进行分析,以λ=0.68为聚类阈值,可将9种菜田优势种蜘蛛划分为1个明显竞争群及3个分离种。以λ=0.9736为聚类阈值,可将菜田蜘蛛时间序列分为5月份,6、7月份和8月份3个状态集,即蜘蛛群落建立、发展和瓦解3个阶段。     

How to avoid becoming a prey: Predatory encounters between an orb-weaving spider,Araneus pinguis (Karsch) (Araneae: Araneidae) and flying insects

Insects flying into the web of an orb-weaving spiderAraneus pinguis (Karsch) and their avoidance of (pre-hitting process) and escapes from (post-hitting process) the web were examined by direct observation under natural and semi-natural conditions. In the pre-hitting process, mobile insects such as Brachycera, Lepidoptera and Hymenoptera showed a low hitting ratio (number of insects hitting/number of insects flying within 1 m³ space around the web-site) because of active web avoidance and flying activity in layers lower or higher than those in which the webs are usually laid. In contrast, less mobile insects like Heteroptera, Coleoptera and Homoptera showed a high hitting ratio. In the post-hitting process, Brachycera, Lepidoptera and some Nematocera frequently escaped without being detained by the web. Many Orthoptera and Hymenoptera escaped without any sign of detection by the spider. Coleoptera frequently escaped during the spider's attack. Small insects from the Homoptera, Nematocera and Hymenoptera rarely escaped from the web, but were not immediately attacked. Mean escape time of insects was correlated significantly with capture success of the spider. Overall most of the escapes occurred in the early phases of the predation process. This indicates that escapes are unlikely to result in heavy loss of time and energy expenditure due to unsuccessful predation. Escape patterns of insects seem to be related to their mobility.     

大腹园蛛(Araneus ventricosus)粗毒双向电泳及质谱分析

以大腹园蛛粗毒为材料,用固相pH梯度等电聚焦IPG(immobilized pH gradient)和SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis)获得蛋白质组双向电泳图谱,经Bio-Rad公司的PDQUEST软件进行图像分析,检测到500个左右的蛋白质点．对其图谱的部分蛋白质点酶解后使用Micromass公司的ESI-Q-TOF进行了鉴定．得到了质量较好的MS／MS数据．然后将其在MS-Fit中的genepeptide数据库和Mascot的Swissprot中进行搜索从而对蛋白质点进行鉴定．目前初步获得5个组分的鉴定结果．