• Journal of Ecology and Environment
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• v.38 no.2
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• pp.157-162
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• 2015

The physical factors of Argiope bruennichi (Araneae, Araneidae) that influence the stabilimentum decoration on the web, a conspicuous white silk structure reflecting much more ultraviolet light than other spider silks in the web, have been poorly understood. In this study, individual variables involved in decorating the webs with stabilimenta by A. bruennichi were examined. The results revealed that the physical condition of the female A. bruennichi affected the behaviors of the stabilimentum decoration on the web. Among the 82 female spiders building their webs, the 49 female spiders adding upper and lower stabilimenta on their web weighed less, and had a narrower cephalothorax and shorter abdomen than the 33 female spiders that did not use stabilimentum. The heavier females decorated their webs with stabilimentum of greater widths. There were also significant positive relationships between the stabilimentum area and the female spider's cephalothorax width, and between the stabilimentum area and female spider's abdomen length. Taken together, this study suggests that spiders allocate their resources in stabilimentum decoration as a functional response to the spider's physical conditions, and also supports the "prey-attraction hypothesis," which states that the use of stabilimentum increases the foraging success by attracting more prey to the web.

• Korean Journal of Environmental Biology
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• v.28 no.2
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• pp.108-113
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• 2010

Spider fauna of Mt. Gajisan in Miryang, Gyeongsangnam-do was investigated from June to October. Collecting spiders was made by sweeping, beating, sieving and pitfall trapping. Total 66 species of 59 genera belonging to 20 families were identified from 317 collected spiders. Species richness was high in Salticidae (12 species, 20.0%), Theridiidae (8 species, 12.1%), Linyphiidae (5 species, 7.6%), Araneidae, Corinnidae, Gnaphosiade and Thomisidae (4 species, 6.1% repectively), Tetragnathidae, Amaurobiidae and Philodromidae (3 species, 4.5% repectively). Zoogeographical species were 1 Pantropical species (1.5%), 4 Palearctic species (6.1%) and 3 Korean endemic species (4.5%). This result will be a valuable monitoring data in comparative study of mountain spiders.

• Journal of Forest and Environmental Science
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• v.34 no.3
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• pp.262-274
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• 2018

Spider fauna of Demilitarized Zone (DMZ) and adjacent areas in Korea was surveyed in 2001-2003, 2013-2015, and 2017. Total of 34 surveyed areas across 10 provinces were divided into four main regions (east coast, mid-east mountain, midland, and west coast areas) in accordance with administrative districts and topography. Total of 273 species of 145 genera in 32 families were identified from 10,886 collected spiders. In conclusion, the spider fauna in the DMZ is 281 species of 147 genera in 32 families with 162 species of 99 genera in 23 families in the previous reports. This corresponds to about 37.6% of the Korean spiders as of 2015. The species richness among surveyed localities was ranged 45 species to 92 species. The species richness of each taxon is high in Araneidae, Salticidae, Linyphiidae and Theridiidae. Habitat generalists were 22 species and habitat specialists were 69 species. The 143 species were web builders and 130 species were wanderers by the outlined life style. In DMZ spiders, only 7 species, Thymoites ulleungensis, Arcuphantes pennatus, Lycosa coreana, Allagelena koreana, Cybaeus mosanensis and Cybaeus triangulus, Kishidaia coreana, were recognized as Korean endemic. Five species, Scytodes thoracica, T. ulleungensis, Lycosa labialis, Takeoa nishimurai, and Phrynarachne katoi, are rare species with a trend of decreasing density in recent years. Araneus rotundicornis has been discovered for the first time since its first report. This study may be useful in the conservative management and will contribute to knowledge of the distribution and biogeography of DMZ areas in the future.

• The Korean Journal of Zoology
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• v.33 no.3
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• pp.354-364
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• 1990

The ultrastructure and silk formational process of the flagelliform glands, one of the capture thread producing organs in the orb web spider (Nephila clavata L. Koch), have been studied with electron microscope. A pair of flagelliform glands consist of three distinct regions: excretory duct, storage sac and convoluted tail. This gland is connected to the large spinning tube (spigot) of the posterior spinnerets with two pairs of aggregate glands, and showed a characteristic spigot structure called "triad". The excretory duct consists of three long segments surrounded by the same sheath of connective tissue. The distal duct near the spinning tube bears the electron lucent subcuticles which have the functions of water removal and orientation of the silk fiber, whereas the proximal duct near the sac contains the cuticule precursor transported through the intercellular space. Cytoplasms of the sac and tail regions have well developed rough endoplasmic reticulum and contain the round secretory granules commonly, but the electron densities and internal textures of the granules do not coincided. Adjacent epithelial cells are connected with the specialized septate junctions, and secretory granules accumulated at the apical pole are released to the lumen by the apocrine secretion.secretion.

• The Korean Journal of Zoology
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• v.32 no.3
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• pp.211-220
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• 1989

The fine structure of the aggregate glands-one of the capture thread producing organs-in the orb web spider, Nephila clavata L.Koch, is studied with light and electron microscopes. Gluey capture threads or sticky spirals of the orb web are originated from the silks of two flagelliform glands and four aggregate glands which are connected to the posterior spinnerets, and the arrangement fo their spigots(large spinning tubes) shows a charaterstic form called "triad". The aggregate galnd is composed of large and multilobed secretory portion and thick excretory duct surrounded by large irregular nodules. The excretory duct of the aggregate galnds basically consists of three superposed types of cells which are inner columnar epithelium, nodule-forming cells and outer connestives. The cuticles of the proximal duct near the secretory portion are composed of endocuticle and exocuticle, whereas ghe distal duct near the spinning tubes has a electron lucent subcuticle which had the functions of water removal and orientation of silk fibers. In the cytoplasmic process of the large and irregular nodule-forming cells surrounded by invaginations of the plasma membranes, numerous mitochondria and glycogen particles are contained. The maturational level of the nodule cells is perceived from the appearence of these cell inclusions. The secretory portion of the glands which porduce the secretory silk material shows two layers of the cells which are simple cuboidal epithelium and several connective layers. In the cytoplasm of the glandular epithelial cell, rough endoplasmic reticulums are well developed, and two types of secretory granules are observed. Between the adjacent epithelial cells, specialized septate junctions are formed along the plasma membranes.membranes.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.209-215
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• 2020

Debates over the ecological and public health impacts of aerial pesticide sprays are increasing. This is particularly true for controlling Monochamus beetles, which are vector insects of pinewood nematodes. In 2017, adult female orb-web spiders, Trichonephila clavata, were sampled from pine forests in Yangsan-si, Gyeongsangnam-do, Korea, where the aerial pesticide spray, fenitrothion or thiacloprid, was used for several decades. The biological traits of the spiders (body weight, body length, carapace width, and total hind leg length) were compared among treatment sites (no-spray, sprayed three times, and sprayed five times), and differences were observed. The body length, carapace width, and total hind leg length of the spiders in the sprayed areas were significantly shorter than in the no-spray area, but there were no differences between the area sprayed three or five times. These results indicate that repeated exposures to an aerial pesticide spray can alter morphological parameters, which influences population-level fitness. Future studies should monitor the spider long-term responses to pesticides (a direct effect) and prey availability (an indirect effect).

• The Korean Journal of Soil Zoology
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• v.5 no.1
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• pp.21-32
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• 2000

A faunistic study on the spiders (Arachnida: Araneae) from Mt. Jumbong Kangwon-do was carried out from 1996 to 1999. During the survey period, 144 species of 88 genera belonging to 27 families including 5 undetermined species were identified from 900 collecting individuals. The dominant families were Linyphiidae 21 species; 14.6% of total species), Araneidae (20 species, 13.9%), Theridiidae (16 species, 11.1%), and Salticidae 12 species, 8.3%). The composition of the species of web builders was richer than that of hunters. As for species commonness with adjacent countries, the numbers of common species between Mt. Jumbong and Japan, Mt. Jumbong and China, and Mt. Jumbong and Russia were 15 species (80.4%), 98 species (68.5%), and 48 species (33.6%), respectively. The number of common species among these four regions were 39 species (27.3%). So, the spider species composition in Mt. Jumbong seemed being much similar to those in neighbor countries. An outline of biogeographical distribution of spiders can be summarized as 1 Cosmopolitan species (0.7%), 16 Palearctic species (11.2%), 7 Holarctic species (4.9%), 25 Korean endemic species (17.4%) and no Oriental species. In the spider fauna at Mt. Jumbong, therefore, there are high level of occurrence of Korean endemic species with northern spiders as Palearctic and Holarctic species. The level and direction of man-made development may have negative effect on regional biota.