• Korean journal of applied entomology
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• v.60 no.3
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• pp.277-286
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• 2021

The natural enemy was identified as a parasitic wasp, Binodoxys communis Gahan. B. communis taxonomically belongs to the family braconidae, subfamily aphidinae, and genera binodoxys. It develops normally at 17.5 to 32.5℃, and not at 35℃. Depending on the temperature, the longest development period of B. communis was 21.9 days at 17.5℃, and shortest was 6.46 days at 32.5℃. The effective accumulated temperature was 175.44 DD for females as well as males; however, the developmental threshold temperature was 10.87℃ and 10.74℃ for females and males, respectively. This parasitic wasp was found to prefer cotton aphids and soybean aphids as its prey.

• Korean journal of applied entomology
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• v.48 no.4
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• pp.553-556
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• 2009

We surveyed natural enemies of Pachynematus itoi Okutani, newly recorded sawfly pest of Larix leptolepis, and investigated their occurrence and life cycle at Cheolwon and Taebaek, Gangwon Province in 2006~2007. Endasys liaoningensis was identified as main natural enemy of P. itoi Okutani. Parasitism of E. liaoningensiswas was 42%. Emergence period of E. liaoningensis was from May to September, and the peak of emergence was from 21th May to 20th June. It was suggested that the occurrence number and period of E. liaoningensis were quite closely relative to those of host, P. itoi.

• Journal of Environmental Science International
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• v.32 no.12
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• pp.973-978
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• 2023

This study determined the mechanisms of selection of companion plants that will increase natural enemies and compared and analyzed the effect of suppression of pest density and changes in pest and natural enemy density and spatial distribution, aiming to select suitable companion plants to control major pests that are problematic in organic tomato facility cultivation. As a result of the companion plant selection, 13.5 days were identified in the area with daily flowers among five species of flowering plants. In the experiment to determine the timing of natural enemies, the best results were found in the treatment group introduced two weeks before the pest occurred. As a result of the actual package test, farmers could see that the density of greenhouse pollen decreased significantly (100-500% for adults and 11-67% for larvae compared to no treatment) in the treatment with companion plants. Based on the results of this study, we expect that ecological pest management using companion plants that attract natural enemies will help to increase biodiversity through vegetation management, secure the safe production of organic products and improve the sustainability of agriculture.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.253-259
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• 1985

This paper presents a natural enemy complex of plant and leafhoppers in rice plants and a relationship between the host insects and their natural enemies. Feeding preference of major paddy spiders have been tested. To date, 32 species of natural enemies of plant and leafhoppers have been recorded, including 30 species of parasites and predators (15 parasitoids, 14 predators and nematode) and 2 species of insect pathogens. Some of species have shown great potential for controlling plant-leafhoppers populations; parasites, Anagrus nr. flaveolus, Gonatocerus sp., Haplogonatopus atratus and paddy spiders. Pirata subpiraticus and Gnathonarium dentatum. Plant and leafhoppers-natural enemy relationship have been observed in different developmental stages of the host insects. Pirata sub-piraticus is the most active to searching the host insects and also prefered nymphs to adults.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.861-873
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• 2017

The present study was conducted to investigate the developmental characteristics of Propylea japonica Thunberg (Coleoptera : Coccinellidae), a predator of aphids under laboratory conditions. The development times of the egg and immature stages of Propylea japonica were investigated at ten constant temperatures(15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35 and $38{\pm}1^{\circ}C$; 14L:10D; $60{\pm}5%$ RH). Development time was longest at $17.5^{\circ}C$. The developmental periods of P. japonica from the time of egg oviposited to adult emergence was 36.9 days at $17.5^{\circ}C$, and it decreased ash temperature increasing. Threshold temperature of development and degree days of the P. japonica from egg to adult were $11.9^{\circ}C$ and 196.0 respectively. The Briere 2 and Lactin 2 modes were best fitted for all development stages. The distribution of completion of each development stage was explain relatively well that 2-parameter, 3-parameter and Logistic model except egg and pupal stage.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.115-123
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• 2005

Historical changes of population abundances of European red mite (ERM), Panonychus ulmi (Koch), and two-spotted spider mite (TSSM), Tetranychus urticae (Koch) (Acari: Tetranychidae), were described in selected apple orchards in the National Horticultural Research Institute (NHRI, Suwon, Korea), based on research reports of the NHRI from 1958 to 1998. ERM was an abundant species up to 1970, and TSSM became a dominant species after 1980. The change occurred around mid 1970. Three hypotheses were made to explain the change: TSSM competitively replaces ERM, ground cover weeds are a major influencing factor on movement of TSSM (TSSM movement into trees is accelerated by destroying weeds), and ERM and TSSM populations are regulated by natural enemy complexes when the orchard system is not disrupted. And long-term results of the interaction between two species were projected according to the combination of different orchard management strategies: pesticide sprays (non-selective toxic pesticide spray : heavy pesticide pressure (HPP), and selective soft pesticide spray = low pesticide pressure (LPP)) and weed control methods (grass planting, and clean culture system with herbicides). In the HPP and grass planting system, ERMs are abundant because ERM can avoid competition with TSSM as movement of TSSM to trees are restricted, and natural enemy complexes are destroyed by toxic pesticides. In the HPP and clean culture system, TSSMs are abundant because TSSM moves to trees from early season and competitively replaces ERM. In the LPP and grass planting system, ERMs are abundant because movement of TSSM to trees is reduced, but they do not build up a high population density since their densities are regulated by natural enemy complexes. In the LPP and clean culture system, TSSM moves to trees and competes with ERM, but the competition pressure is reduced because population densities of mites are regulated in a lower level by natural enemy complexes. So, ERM can occurs in late season. Thus, two species can coexist temporarily with more ERM in early season and more TSSM in late season. TSSM abundant phenomenon presented in this study can be partially explained as a result of long-term interaction between ERM and TSSM under the HPP and clean culture system.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.15 no.1
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• pp.27-33
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• 2012

This study was performed in the Tropical Plant Resources Research Center of Korea National Arboretum to assess the effects of natural enemy attack on aphid population feeding on tropical plants. We measured the density of leaf-feeding aphids, Myzus persicae and Aphis gossypii, cohabiting with 5 types of tropical plants at intervals of approximately 2 weeks after introducing their natural enemy, Aphidius colemani. The density of aphids cohabiting with 4 types of tropical plants-Sanchezia parvibracteata, Hibiscus rosa-chinensis, Ficus kurzii, and Aloysia triphylla-started decreasing after 2 weeks of observation and was completely in control after 4 weeks of observation; however, the density of aphids cohabiting with the tropical plant, Hamelia patens, increased during 22 weeks of observation but decreased after the $23^{rd}$ week of observation. We suggest that a banker plant is necessary for the maintenance of A. colemani in tropical greenhouses, and monitoring studies on H. patens, which was weakest against the aphids, should be performed. Our results indicate that biological pest management strategies using their natural enemies were formulated for the construction of new tropical greenhouses.

• Applied Microscopy
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• v.46 no.2
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• pp.89-92
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• 2016

The bluegill Lepomis macrochirus is an invasive species, not native to Korea, introduced for aquaculture. This species is ranked as a new top predator due to its massive aquatic carnivorous and herbivorous nature by acute vision and the absence of a natural enemy. The visual cells of the retina of L. macrochirus are composed of short single cones and equal double cones and long and bulky rods by light and electron microscopes. In particular, the cones show a regular square mosaic arrangement. This pattern is widely considered as a strong predator. With regard to the visual system, this mosaic pattern may closely be related to a dynamic visual acuity to track and hunt prey.

• The Research Journal of the Costume Culture
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• v.9 no.3
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• pp.458-484
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• 2001

The costume originated from the idea that it could protect human beings from ferocious beasts. The military costume was from protection against an enemy equipped with weapons. Furthermore, the makers of the costume were afraid of supernatural powers and it made them devise an armour and decorate it by the concept of superstition for the purpose of overcoming it. The function of military uniform was important for increasing the protection against any enemies while they join in battle. However in harmonious time, it represented artwork of peace, dignity, and order. Since the uniform was a king of symbol to show their position, and their role. They could feel proud as a member of a military group they belong to and they gain honor, courage, patriotic sentiment through their military costume. The purpose of this study was to investigate the originality the military costume as it changed and developed continuously from ancient Egypt, Greece and Rome to modern times. This study was performed to show the comparison and characteristic marks of the past, and the influence of them on the modern military uniform. The method used in this study was using past manuscripts of the early times, information attained from domestic and foreign military documents and previously written reports. As a result, the military costume was one of many means of expression of their natural and social environment. It can be said that the most epoche-marking and powerful changes to the social environment are revolution or war. War absolutely has influenced on the changes of the changes of costume and the military armour according to the type of war and the development of weapons. Especially using the amour, the main purpose that of protecting the body has changed into distinguishing our forces from the enemy and instilling fear into enemy, Furthermore, the class who has the power has used it in order to express their power and dignity. Therefore, armour had required two rules to not only protect the body but also discriminating between classes.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.465-469
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• 2016

An entomopathogenic fungus was isolated from the two-spotted spider mite (Tetranychus urticae) in a rearing house, and identified as Neozygites floridana (Entomophthorales: Neozygitaceae). A high infection rate induced by N. floridana could increase the price of the natural enemy. The body color of mites infected by this fungus changed to red or orange and swelling occurred. Fungal conidia were discharged into the webbing produced by the spider mites, making it relatively easy to infect the mites. Primary conidia were pear shaped and capilliconidia almond shaped. The fungus could not be cultured on solid media (PDA, SDAY, or EYSDA), but could possibly be cultured in liquid media (Grace's insect tissue culture medium + 5% fetal bovine serum). Kidney beans were supplied as food for T. urticae; the mite infection rate in a kidney bean canopy was about 36.1%. The density of infected mites was higher on the underside than on the upper side of leaves. Based on the results of this survey, we need to identify methods of fungal control for natural enemy production and biological control agents for T. urticae for effective crop management.