• Korean journal of applied entomology
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• v.50 no.2
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• pp.141-149
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• 2011

Five erigonine spider species are described with illustrations: a new species, Saitonia pilosus n. sp., and four records new to the Korean spider fauna, Ceratinella brevis (Wider, 1834), Erigone atra Blackwall, 1833, Maso sundevalli (Westring, 1851), and Parasisis amurensis Eskov, 1984. The occurrences of four spider genera, Ceratinella Emerton, 1882, Maso Simon, 1884, Parasisis Eskov, 1984, and Saitonia Eskov, 1992, are also new to Korea.

• Journal of Korean Elementary Science Education
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• v.25 no.spc5
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• pp.465-475
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• 2007

The purpose of this study was to develop a spider inquiry program for elementary school students based on the scientific-knowledge generating model. For the purposes of this study, we selected three species of snider (e.g. Pardosa astrigera, Argiope bruennichii, Nephila clavata) which were easily found in a school garden by elementary school students. The spider inquiry program was based on a model of the process of scientific-knowledge generation, and consisted of two sections: for students and teachers. The students' program was designed to generate scientific-knowledge, whilst the teachers' program was designed to guide the inquiry smoothly even in the case of teachers who lack experience in inquiry activities or possess limited subject knowledge on spiders. As a result, this program was found to have an influence on generating the scientific-knowledge of elementary students and the results further suggest that it may be helpful to teachers conducting an inquiry activity. Additionally, this program could be used as a selective activity lesson such as a science inquiry lesson, or as a biology inquiry class, as a weekend life experience study or as an activity on a science camp.

• Animal cells and systems
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• v.12 no.2
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• pp.109-116
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• 2008

Among the four kinds of silk glands in the funnel-web spider Agelena limbata, the ampullate gland for dragline silk production is the most predominate one in both sexes, and is composed of three functional parts-excretory duct, storage ampulla and convoluted tail regions. Two pairs of major ampullate glands send secretory ductules to the anterior spinnerets, and another two pairs of minor ampullate glands supply the middle spinnerets. There are no apparent differences between the major and minor ampullate glands not only the external spigots but also their internal silk glands. However, the microstructure is very unique in this spider, because each gland has spherical shaped storage sac with twig-like branched tails. Nevertheless, the wall of the secretory region is similarly composed of a single layer of epithelial cells. The mature secretory silks in glandular epithelium are closely packed and accumulated as electron-opaque vesicles. Most of the secretory products which originated from the rough endoplasmic reticula(rER) are grown up by fusion with the surrounding small vesicles however, the Golgi complex does not seem to play an important role in this process of secretion.

• Animal cells and systems
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• v.6 no.4
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• pp.327-333
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• 2002

Among the silk glands in the black widow spider Latrodectus mactans, the ampullate one is the most predominant gland in both sexes, and is com-posed of three functional parts - excretory duct, storage ampulla and convoluted tail regions. This experiment was performed using mechanical pulling stimulation with electric motor equipment to reveal a correlation between silk usage and silk producing system in this poisonous spider. The mature secretory products in glandular epithelium are closely packed and appear as electron-opaque spherical vesicles. A part of the vesicles with fine fibrillar paracrystalline texture seems to store some proteins which will function at the time of final assembly into fibrils. Most of the secretory silk products which originated from the rough endoplasmic reticula of the glandular epithelial cells are grown by fusion with surrounding small vesi-cles. However, the Golgi complex does not seem to play an important role in this process of secretion. According to progressive maturation of secre-tory silk product, these granules are progressively filled with a fine fibrillar material, and thus appear much more electron-dense than those of earlier states. When the secretory product is extruded from the glandular cavity, the epithelium is rapidly changed to a thinner layer of tall columnar cells with less definitive cell membranes. After extruding there ave a few secre-tory droplets within these cells, thus causing this region to stain much lighter.

• Journal of Life Science
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• v.13 no.2
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• pp.150-153
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• 2003

To determine the effect of newly developed insecticide on two spotted spider mite, Tetranychus Urticae, populations, ten leaf discs were sprayed with three different concentrations (0.5%, 1.0%, and 1.5%) of the tested insecticide solution, and with a water-sprayed control. The tested insecticide solution was toxic to adult female and immature of two spotted spider mite, but was relatively non-toxic to eggs. For equivalent concentrations, more adult females were killed than immature stages. There was no marked difference between the hatch of treated and untreated eggs, although a weak trend between the numbers of unhatched eggs and the insecticide concentration after 7 days is shown.

• Applied Microscopy
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• v.28 no.4
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• pp.539-549
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• 1998

The silk glands of the spiders are of several types. Among the several types of spider's silk glands, the principal fibers used in constructing the eggcase are products of the tubuliform glands (TBG), which are present only in females. Development of these glands parallels maturations of the ovaries and fat bodies. In order to understand the mechanism of eggcase-silk production, this paper has examined the fine structural changes of the TBG during the period of egg maturation in the garden spider, Argiope aurentia. Between the two kinds of secretory granules observed in the glandular epithelium of the mature TBG, the electron-dense granules which have paracrystalline structure are revealed to be the precursors of the eggcase silk fibers. During the production of eggcase, rapid release of the secretory product occurs at apical surface by the mechanism of apocrine secretion. Moreover, secondary lysosomes appear due to the rapid disorganization of cellular components during the eggcase formation. Examinations of formed fibers indicate a multicomponent internal structure, and electron micrographs reveal each fiber contains numerous electron lucent fibrils embedded in an amorphous electron dense matrix. The secretory precursors are produced as separated vesicles via well-oriented rER, and no Golgi complex has been found in the glandular epithelial cells.

• Applied Microscopy
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• v.50
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• pp.9.1-9.8
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• 2020

The fine structural characteristics of cardiac muscle cells and its myofibril organization in the orb web spider N. clavata were examined by transmission electron microscopy. Although myofibril striations are not remarkable as those of skeletal muscles, muscle fibers contain multiple myofibrils, abundant mitochondria, extensive sarcoplasmic reticulum and transverse tubules (T-tubules). Myofibrils are divided into distinct sarcomeres defined by Z-lines with average length of 2.0 ㎛, but the distinction between the A-band and the I-bands is not clear due to uniform striations over the length of the sarcomeres. Dyadic junction which consisted of a single T-tubule paired with a terminal cisterna of the sarcoplasmic reticulum is found mainly at the A-I level of sarcomere. Each cell is arranged to form multiple connections with neighboring cells through the intercalated discs. These specialized junctions include three types of intercellular junctions: gap junctions, fascia adherens and desmosomes for heart function. Our transmission electron microscopy (TEM) observations clearly show that spider's cardiac muscle contraction is controlled by neurogenic rather than myogenic mechanism since each cardiac muscle fiber is innervated by a branch of motor neuron through neuromuscular junctions.

• Applied Microscopy
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• v.50
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• pp.20.1-20.9
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• 2020

Arthropods have an open circulatory system with a simple tubular heart, so it has been estimated that the contractile pumping structure of the cardiac muscle will be less efficient than that of vertebrates. Nevertheless, certain arthropods are known to have far superior properties and characteristics than vertebrates, so we investigated the fine structural features of intercalated discs and cardiac junctions of cardiac muscle cells in the black widow spider Latrodectus mactans. Characteristically, the spider cardiac muscle has typical striated features and represents a functional syncytium that supports multiple connections to adjacent cells by intercalated discs. Histologically, the boundary lamina of each sarcolemma connects to the basement membrane to form an elastic sheath, and the extracellular matrix allows the cells to be anchored to other tissues. Since the intercalated disc is also part of sarcolemma, it contains gap junctions for depolarization and desmosomes that keep the fibers together during cardiac muscle contraction. Furthermore, fascia adherens and macula adherens (desmosomes) were also identified as cell junctions in both sarcolemma and intercalated discs. To enable the coordinated heartbeat of the cardiac muscle, the muscle fibers have neuronal innervations by multiple axons from the motor ganglion.

• Animal Systematics, Evolution and Diversity
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• v.3 no.2
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• pp.64-116
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• 1987

The purpose of the present paper is to record taxonomic notes on several Korean spider mites. The specimens on which this study is based were collected by the authors during the period from May, 1986 to June, 1987. The following species are the spider mites concerned in this paper. 1. Panonychus citri (McGregor), 2. Eotetranychus populi Koch, 3. Eotetranychus smithi Pritchard and Baker, 4. Shizotetranychus bambusae Reck, 5. Schizotetranychus celarius (Banks), 6. Shizotetranychus leguminosus Ehara, 7. Oligonychus orthis Rimando, 8. Tetranychus ranzawai Kishida, 9. Tetranychus phaselus Ehara, 10. Tetranychus trancatus Ehara , 11. Tetranychus vienensis Zacher, 12. Tetranychus urticae Koch . Among them, eight species with asterisk are newly recorded from Korea . In addition, empodiums of pretarsus were carefully observed and enzyme patterns by electrophoresis were compared on some species in order induce their systematic inter-relationship at either species or generic level.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.1
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• pp.43-49
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• 2002

We have cloned cDNAs encoding toxin from the spider, Araneus ventricosus, and constructed a recombinant baculovirus expressing the insecticidal toxin. The cDNAs encoding toxin were cloned from the cDNA library of A. ventricosus. Sequence analysis of the cDNAs encoding the toxin of A. ventricosus revealed that the 240 bp cDNA for AvTox-1 and 192 bp cDNA for AvTox-2 have an open reading frame of 80 and 64 amino acid residues, respectively. The deduced protein sequence of the toxin genes of AvTox-1 and AvTox-2 was aligned to that of the snack Anemonia sulcata and scorpion Centruroides limpidus limpidus, respectively. Northern blot analysis indicated that AvTox-2 toxin gene showed a fat body-spe-cific expression pattern at the transcriptional level. Furthermore, we have explored the possibility of improving baculovirus by incorporating the A. vontricosus toxin gene into Bombyx mori nuclear polyhedrosis virus genome under the control of polyhedrin promoter, The AvTox-2 toxin gene was expressed as approximately 5.8 kDa band in the recombinant baculovirus-injected silkworm larvae. Bioassays with the recombinant virus expressing AvTox-2 on 5th instar silkworm larvae demonstrated a decrease in the time to kill $(LT_{50} days)$ compared to wild-type BmNPV-Kl $(LT_{50} 6.72 days)$ in the injection of 10 viruses. These results indicate that A. ventricosus toxin is a novel member of the spider toxin family, suggesting that the toxin gene can be used in recombinant baculoviruses to reduce insect feeding damage and increase the speed of insect kill.