• Journal of Environmental Health Sciences
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• v.28 no.4
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• pp.17-22
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• 2002

In crustaceans, as in other arthropods, the molt cycle and the physiological process of growth are controlled by molting hormones (MH) which are steroid hormones, the ecdysteroids. Ecdysteroids are major arthropod hormones which control both development (embryonic and larval molts, metamorphosis) and reproduction. The purpose of the present study was to evaluate both fenarimol and methoprene for embryotoxicity to daphnids. The embryotoxicity associated with each compound was assessed to discern whether the embryotoxicity of methoprene might be due to ecdysone agonist and the ecdysone antagonistic effects of fenarimol on Daphnia embryo. Exposure of daphnids for three weeks to 50 M methoprene resulted in a significantly high incidence of offspring that exhibited general toxicity. This exposure concentration had significant effects on the overall number of embryo death. However, exposure to 3 or 1 $\mu$M fenarimol were no significant effects on the embryo toxicity. The incidence of both of these toxicity increased with methoprene exposure. This observation suggest that methoprene showed embryonic general toxicity during embryo development, while, only fenarimol showed weak general toxicity with early stages of embryonic development.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1427-1432
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• 2008

This paper describes the locomotion of a water jumping robot which attempts to emulate the fishing spider’s ability to jump on the water surface. While previous studies of the robots mimicking arthropods living on water were focused on recreating their horizontal skating motions, here we aim to achieve a vertical jumping motion. The robot jumps by pushing the water surface with rapidly released legs which were initially bent. The motion is triggered with a latch driven by the shape memory alloy actuator. The robot is capable of jumping to the maximum height of 26mm. Jumping efficiency, defined the maximum jumping height on water over the maximum jumping height on rigid ground, is 0.26 This work represents a first step toward robots that can locomote on water with superior versatility including skating and jumping.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.10a
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• pp.187-188
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• 2002

Chitosan is a natural biopolymer of N-acetylglucosamine (-1,4 linked 2-acetamido-D-glucose), which is obtained after alkaline deacetylation of the chitin derived from the cell walls of lower plants and in the skeletal tissues of lower animals including arthropods and mollusks. In the recent studies, chitin and chitosan have attracted interest for converting them to oligosaccharides because the oligosaccharides are not only water-soluble but also possess versatile functional properties such as antimicobial activity (Jeon and Kim, 2000; Jeon et al., 2001). (omitted)

• Korean journal of applied entomology
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• v.26 no.3 s.72
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• pp.133-138
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• 1987

This study was conducted during Oct. 1986$\sim$Apr. 1987 to investigate the distribution, dominance and species diversity of soil arthropods communities from two collection sites of Suwon and Mt. Jiri. A total of 2,989 specimens of 3 orders, 20 families and 19 species were identified. In overall dominance index, Suwon community showed lower value than Mt. Jiri community. Seasonal variation dominance index were higher in Suwon community than those in Mt. Jiri community.

• Animal Systematics, Evolution and Diversity
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• v.37 no.1
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• pp.64-69
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• 2021

The genus Krenosmittia is a small group of Orthocladiinae, containing a total of twenty species in the world. Among them, six species were found in Japan, four species in China, and five species from the Russian Far East. This genus can be distinguished from other Orthocladiinae genera by the eyes bare, absence of acrostichals on thorax, costa strongly extended, anal vein ending proximal to FCu, squama bare, and having a strongly developed virga. We report three new species: K. danyangensis n. sp., K. triangulia n. sp., and K. pseudoannulata. The genus Krenosmittia is the first record in Korea. Line drawings of the diagnostic characters are provided for all the species recognized in this study.

• Animal Systematics, Evolution and Diversity
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• v.37 no.1
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• pp.70-77
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• 2021

The genus Parorthocladius is a small group among the subfamily Orthocladiinae (Diptera: Chironomidae). A total of ten species of Parorthocladius have been recorded in the world, of which two species were found from Japan, three species from China, and three species from the Russian Far East. Only one species, P. nudipennis is widely distributed in Europe and the Russian Far East. This genus can be distinguished from other genera by the absence of acrostichals on the thorax, wing vein R4+5 ending proximal to the tip of vein M3+4, anal point parallel side, rounded apically. We report four new species of Parorthocladius collected in Korea and described them with illustrations. As a result, fourteen species of Parorthocladius have been recorded in the world.

• The Korean Journal of Zoology
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• v.21 no.3
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• pp.103-125
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• 1978

The present papers (I and UU) deal with the total records of Korean subterranean animals reported during the last forty years since its first one in 1938 through 1978. They have been published in 33 different articles by 29 authors from 7 different countries. They enlist 109 species in 53 families in 7 classes belonging to 3 different phyla collected from 45 caves and 9 wells around the country. Predominant are arthropods enumerating 101 species (92.7%), of which insects are represented by 37 species. The number of species reported exclusively from subterranean habitats, presumably troglobionts, amount to 60 (55%). Discussions regarding the systematic situation of each taxa in question are made and the rate of occurrences of totally subterranean animals is determined and compared by respective taxa in a few different geographic regions. Also checklists are prepared and given in systematic order, which are followed by general analysis. Some attempts are also made to give suggestions, hopefully, for the prograess and improvement of korean biospeleology. the present article, Part I, will be completed by Part II dealing with insects which sppears in the Korean Journal of Entomology Vol. 8, No. 2 of the 1978 edition.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.601-615
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• 2013

This study was conducted to compare the community structure and biodiversity of arthropods between conventional and organic red pepper fields. A total of 36 species of 24 families belonging to 10 orders from collected 28,718 arthropods; 6,901 individuals from conventional field and 21,871 individuals from organic field. A number of species comprising arthropod community was same in both fields as 32 species. Species richness of Diptera was the highest in conventional field and that of Hymenoptera and Colembolla was the highest in organic field. Abundance of Frankliniella intonsa was the highest regardless of farming method. Helicoverpa assulta was dominant in conventional field, and Homidia mediaseta, Diptera sp. 4 and Pardosa astrigera were dominant in organic field. Diversity of community on the ground was higher in organic field and statistically different. Similarity of arthropod community showed difference with 34.07% on the ground and 26.95% in the plant above ground. In the ecologically functional guild: species richness of general, pest and parasitoid of natural enemy groups in the plant above ground were statistically different and pest and parasitoid groups were higher in organic field, abundance of predator group of natural enemy on the ground was 2 times higher in organic field and statistically different and diversity of general and parasitoid groups in the plant above ground were statistically different. In the relative occupancy rate, pest group was the highest in conventional field and decomposer group was the highest in organic field. The results of present study is considered to provide useful information of arthropod community for developing efficient insect pest management in organic farming.

• Korean journal of applied entomology
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• v.49 no.1
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• pp.23-29
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• 2010

The environmental risks of cucumber mosaic virus resistant transgenic chili peppers with the CMVP0-CP gene on non-target organisms in the agroecosystem environments was evaluated during the periods of the chili pepper growing season (June 19, July 30, August 31) in 2007. Arthropods assemblages leaves and flowers of chili peppers were quantitatively collected by using an insect vacuum collector to compare the arthropod community structures between non-transgenic chili peppers (nTR, P 915) and mosaic virus resistant transgenic chili peppers (TR, CMV-cp, line 7). There was no statistical difference in the arthropod community structure between the two types of crops, nTR and TR, at the same season, although the species richness and Shannon's index were somewhat different among seasons; indicating no effects of genetically modified peppers on the arthropod community. However, further studies were required to conclude more concretely for the potential environmental risk of the transgenic chili pepper of CMV-cp.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.55-66
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• 1997

This study was conducted to analyze arthropod community patterns in small rice fields associated with different planting methods (water seeding, drill seeding, and hansplanting) in Suwon and Icheon in 1994. Total 15 orders and 45 families of arthropods were collected. The arthropod community was analyzed using guild categories. The arthropods were found in the order of 'natural enemy>pest(phytophage)>non-pest' in their densities in all sites. The pest (phytophage) species were mainly Homoptera and dominated by Delphacidae (Nilaparvata lugens Stsl, Sogatella fircifera Horvath and Laodelphax striatellus Fallen) and Cicadelidae (Nephotettir cincticeps Uhler). They constituted >80% of pest abundance. Differences in pest abundance were not found among rice fields associated with different planting methods. Spiders were the most dominant group in the natural enemy and constituted >90% of natural enemy abundance. Hunting spiders constituted >SO% of spider abundance and were dominated by Pirata subpiraticus Bos. et Str. (Lycosidae). Pacliygnatha clerki Sundevall (Tetragnathidae) was a dominant species in webbing spiders. No differences were found in species richness and diversity in spider community among rice fields associated with different planting methods. The nonpest species were mainly Diptera and occurred abundantly in early growing season and decreased drastically as rice development proceeded. The non-pest abundance was higher in direct seeding sites than in transplanting site, and especially abundant in a drill seeding site.