• The Korean Journal of Ecology
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• v.20 no.5
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• pp.375-384
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• 1997

The effects of three different irrigating water qualities(clean water, life sewage and animal sewage) on the pattern of arthropod communities in the rice fields were investigated at Banwol, Kyonggi-do, mid-western part of Korea from 1994 to 1996. The total density of arthropod was highest in the rice field which was irrigated with clean water(clean water field), and the arthropod community was mainly composed of aphids and collembolans. Each functional group was found in the order of 'pests>non-pests>natural enemies' in its density. The dominant taxa in the pest group were aphids, planthoppers(Delphacidae), leafhoppers(Cicadelidae) and rice water weevil(L. oryzophilus). In the non-pest group collembolans, non-biting midges and dipterans were main arthropods, and in the natural enemy group Araneae was the dominant taxon. In the early growth stage of rice plant the dominant functional group was pests, and in the mid growth stage both the pest and the natural enemy group became dominant. But in the late growth stage none of the functional group was dominant over the other functional groups. The densities of spiders were much more higher in the clean water field than in the other fields. And through all the growth stages of rice plants the density of spiders in clean water field kept increase in contrast to the others. The species composition of spiders in the life sewage field was similar to that in the animal sewage field, but in the clean water field it was different from the other two fields.

• Journal of Ecology and Environment
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• v.32 no.1
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• pp.19-25
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• 2009

An arthropod community in a rice ecosystem was surveyed to determine the impact of two insecticides frequently used in Korean rice ecosystems: carbofuran 3GR, which targets the rice water weevil, Lissorhoptrus oryzophilus Kuschel (Coleoptera: Curculionidae) in the early season and fenobucarb EC, which targets the brown planthopper, Nilaparvata lugens ($St{\aa}l$) (Hemiptera: Delphacidae) in the mid- and late seasons, respectively. Overall, the application of the insecticides reduced density of total arthropods by 48.4% compared to the untreated field, but their impact on each functional group were different. Carbofuran GR treatment on 1 June reduced the L. oryzophilus population significantly until mid-season. The population of filterfeeding chironomids was also reduced by 50%, whereas the spider population was less disturbed. Fenobucarb EC treatment on 16 August significantly reduced N. lugens and detrivorous entomobryid populations until the late season. Both web-building and wandering spiders were also significantly disturbed by fenobucarb EC although the impact differed according to their behavioral differences. While the population of web-building spiders significantly decreased over time, that of wandering spiders recovered from the disturbance a few weeks later.

• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.52-56
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• 2014

BACKGROUND: It is known that impacts of climate change on damage occurrence by insect pests and diseases are increasing. The negative effects of climate change on production will threaten our food security. It is needed that on the basis of analysis of the impacts, proper strategies in response to climate change are developed. METHODS AND RESULTS: The objective of this paper is to estimate impacts of climate change on rice damage occurrence by insect pests and diseases, using the panal model which analyzes both cross-section data and time series data. The result of an analysis on impacts of climate change on rice damage occurrence by pest insect and disease showed that the damage occurrence by Rice leaf roller and Rice water weevil increased if temperature increased, and damage occurrence by Stripe, Sheath blight, and Leaf Blast increased if precipitation(or amount of sunshine) increased(or decreased). CONCLUSION: Adaptation strategies, supplying weather forecasting information by region, developing systematical strategies for prevention of damage occurrence by pest insect and disease, analyzing the factors of damage occurrence by unexpected pest insect and disease, enforcing international cooperation for prevention of damage occurrence are needed to minimize the impacts of damage occurrence on rice production.

• Korean journal of applied entomology
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• v.5_6
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• pp.33-38
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• 1968

쌀바구미의 유충을 3기로 구분하여 각종 농도의 Apholate를 처리하여 그의 치사율$\cdot$발육속도$\cdot$산란수$\cdot$불임률 및 그의 지속성 여부를 조사하여 다음과 같은 결과를 얻었다. (1) 당대 치사율은 농도가 높아짐에 따라 높아 켰으며, 유령기 처리시의 치사율은 노령기 처리시보다 높았다. (2) 차대 치사율은 처리된 성에 따라 차가 있었고 전체적으로 자충 처리시가 자충 처리시보다 높아 치사돌연변이 유기율이 웅충 처리시에 높아짐을 알 수 있었다. (3) $0.5\%$ 이상의 처리구에서는 우화 성충 중에 각종 기형이 출현하였으며, 그 수는 농도가 높아짐에 따라 컸다. (4) 산란수의 감소는 자충 처리시가 웅충 처리시보다 심하였으며, 이것은 Apholate의 난자형성에 미치는 직접적인 영향이라고 생각된다. (5) 발육속도는 노령기 처리시가 유령기 처리시보다 늦어지며, 그 효과는 농도의 증가에 따라 높아진다. 차대의 생육기간은 자충 처리시가 웅충 처리시보다 길어졌다. (6) 화학적 불임제는 당대의 영향뿐 아니라 차대에도 그 영향력이 지속된다.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.515-520
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• 2017

Sexual dimorphism of the mouthpart, antenna and mandible of the Cyllorhynchites ursulus in South Korea was studied with linear measurements. The mouthpart and antenna measurements were conducted with a stereoscopic microscope using 122 specimens (72 males and 50 females). Microscopic observation of the mandible were conducted with a Field Emission Scanning Electron Microscope (FE-SEM) using 103 specimens (73 males and 30 females). Results showed that the size difference between males and females was significant in the size of the mouthpart and antenna. On the other hand, we could not detect sexual size dimorphism in the microstructure of the mandible. The bivariate plots made by the result of Principal Component Analysis (PCA) and Discriminant Analysis (DA) showed a size dimorphism in the size of the mouthpart and the antenna between males and females. Based on our study, sexual dimorphism in the mouthpart and antenna exists in C. ursulus from the South Korean population, and this difference seems to be related to the behavioral differences between males and females.

• Journal of agricultural medicine and community health
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• v.41 no.2
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• pp.63-74
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• 2016

Objectives: We surveyed the awareness and current status of using fumigant carbon disulfide for exterminate Curculio sikkimensis among chestnut farmers in Chungnam Province to suggest directions for health education and public relations. Methods: We designed questionnaires to evaluate recognition of fumigant carbon disulfide. We conducted a questionnaire survey to assess recognition and recognition level of fumigant carbon disulfide by the study variables. Results: The recognition status for fumigant carbon disulfide was 74.5%, but the recognition level was low (know well 27.5%). The path of recognition was 45.1% and 15.7% for neighbor and rural technology center, respectively. The recognition status for warning label of fumigant carbon disulfide was 52.9%. Recognition for warning label of fumigant carbon disulfide was tended to increase with high educational attainment, bigger owning land area. Recognition on the content of warning label were 29.4%, 27.5%, 21.6%, and 21.6% for inflammability, toxicity, hazard, and explosiveness, respectively. Using personal protection equipment was tended to increase with the high status of awareness on fumigant carbon disulfide. Conclusions: Health education programs for using fumigant carbon disulfide are needed for chestnut farmers. In addition, publicity information activities about prevention and protection of carbon disulfide poisoning are needed for high risk farmers.

• Korean journal of applied entomology
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• v.4
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• pp.67-74
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• 1965

The work on the 'Studies of radiosensitivity' in Korea has been initiated since 1959 by the author at various institutions in home and foreign countries, and more than 20000 of plant materials in 73 varieties and 41 kinds are treated under varied conditions for the studies of radiosensitivity in plants. However, a study of the susceptibility to radiation in insect pests as well as their biological effects has not been previously reported in this country. During the year of 1964 and 1965, near 50000 of insects at the stages of adult, egg, larva and pupa in 14 different kinds are irradiated under acute X and gamma rays to investigate the behavior of growth and lethality after irradiation, and thrir general tolerances to radiations are compared by the kind of insects, stage of growth, radiation sources and exposured dosages. Through the experiments, it is shown that the lethality in most of insects are high as several kilo roentgens above and no significant effects on pupation. emergence, and oviposition in the treated generation at the dose of 3 Kr. below, but in the following generation , the rice stem borer for instance, no oviposition or decreased laying is observed from the dosages at 3 Kr. to 1 Kr., and the hatching was possible from 1.5 Kr. below of irradiated larvae although laying and hatching are seemed in normal. In general, the lethal dose $50\%$ of tested infect materials at the larval stage can he classified some what 60-80 Kr. for Pine caterpillar, Fall webworm, Camphor silk moth and their relatives, at 40-60 Kr. for Gypsy moth, Monley prominent and some relatives and at 20-30 Kr. for House fly, Rice weevil, Pine sawfly etc. Plant parasitic nematodes such as Hirschmannia and Paratylenchus shown very high resistance to radiation and the LD-50 is observed from 100 Kr. or above. A concept to evaluate the radiosensitivity in insects by taxological family line as a practical measure is not answerable yet, but it ran he solved within the near future through the continuing experiments.

• The Korean Journal of Pesticide Science
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• v.2 no.1
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• pp.18-23
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• 1998

In order to obtain leading compound for the development of new pesticide through the organic synthesis of natural products, the synthesis of ricinine, an active compound of Ricinus communis, was established and biological activities of synthetic compounds against insects were examined. The synthetic scheme of ricinine was composed of four steps by the spontaneous condensation of the cyanoacetyl chloride. A modified synthetic process was also estabilshed to enhance the synthetic yield by simple cyclization of ethoxymethylene malononitrile. In the bioassay results of synthetic ricinine and intermediates on four insects, the mortality of ricinine on brown planthopper (BPH, Nilaparvata lugens) and pea weevil(PW, Bruchus rufimanus) was 80% and 75% at the concentration of 1,000 ${\mu}g/ml$ respectively. Chloronorricinine and chlororicinic acid having chloride group in molecular structure gave 60% mortality on two-spotted mite (TSSM, Tetranychus urticae) at the concentration of 500 ${\mu}g/ml$. The mortality of compounds on house mosquito (HM, Culex pipens pallens) was meager at 10 ${\mu}g/ml$ level.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.2
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• pp.41-45
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• 2013

Extractives of garlic (Allium scorodorpasum) and green pepper (Capsicum annuum L.) were used to prevent and exterminate rice weevils which contaminate stored rice. The extractives exhibited great efficacy against Sitophilus oryzae and Tribolium castaneum by annihilating all the weevils contained in a bottle. Furthermore, kraft paper coated by 5% extractives also displayed good effectiveness against the rice weevils. When rice weevils were stored with rice in a sack made of extractives-coated kraft paper, the number of living insects was sharply decreased according to elapsed time. In particular, 1,4-benzoquinone, which is very harmful to human, was detected from rice contaminated by Sitophilus oryzae and Tribolium castaneum through the analysis of GC/MS.

• Applied Biological Chemistry
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• v.31 no.2
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• pp.143-146
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• 1988

The effect of gamma irradiation on controlling infestation of insects on rice grain were investigated. The egg and larva stages of rice weevil (Sitophilus oryzae) were more radiosensitive than the pupal and adult stages. The complete mortal dose of the first two stages was 0.05kGy, while it was 0.5kGy in the second two stages. In indian-meal moth (plodia interpuctella Hubner), sterile doses of egg, larva, pupa and adult were 0.04 to 0.05, 0.05 to 0.06 and 0.2 to 0.25kGy, respectively. Therefore, the irradiation dose within 1.0kGy was considered to be effective for rice storage so far as reinfestation was prevented. Attractiveness of indian-meal moth toward the rice irradiated at 1.0 to 5.0kGy was non-significant in F-test.