• Korean journal of applied entomology
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• v.29 no.3
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• pp.176-179
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• 1990

Seasonal occurrence in each stages of rice water weevil, Lissorhoptrus oryzophilus Kuschel, was studied in paddy field transplanted on May 25, Siehung, 1989. The peak of overwintered adults was late May an that of newly emerged adults was early August. Oviposition occurred in late May and late June and its peak was observed on early June. Larvae were observed from early June to early August and pupation occurred from early July to late August. The first adults of newly emerged rice water weevil was observed on early July and its emergence peak was early August.

• Korean journal of applied entomology
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• v.29 no.1
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• pp.6-13
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• 1990

The banana insect pest species and their damages were surveyed from 9 vinyl hoses of Cheju Island on August in 18. A total of 5 pest species wre found ; banana root weevil (BRW) Cosmopolites sordidus Germar (Curculionidae) a wireworm Melonotus sp. (Elateridae), a spider mite teranychid sp. (Tetranychidae), mulberry mealybud Pseudococcus comstocki (Kuwana)(Pseudococcidae), and common cutworm Spodoptera litura (Fabricius)(Noctuidae). Among them, the BRW which attacked the rhizome of banana plant was newly recorded from Korea. It is assumed that the weevil would be introduced from Japan, Philippine or SriLan-Ka wiht the banana seedlings imported during early 1980's.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.399-402
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• 1985

Polished rice was stored for 24 weeks at $28^{\c수분함량이 16.0% after infestation with rice weevil (Sitophilus oryzae), inoculation with a storage mold, or both treatment. The moisture contents of stored rice with and without rice weevil were 16.6%-17.3% and 13.70%-14.1% respeotively. Fungal numbers were $4.3{\times}10^{6}$/g to $7.2{\times}10^{6}$/g with insects while no fungal growth occurred without them. There were considerable differences between rice weevil infested- and non-infested rice in rice kernel hardness, 1000 kernel weight, maximum viscosity on amylogram, reducing sugar content, fat acidity, and n-hexanal content in head space gas.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.377-380
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• 2001

Herbivory is an important selective forces on plants by reducing the ability of the plant to compete with its neighbors and to produce offspring. Oak nut weevil(Mechoris ursulus Roelofs) females lay eggs in unmatured acorns and cut off the branch of oviposited acorns. To investigate the influences of branch-cutting behavior of oak nut weevils on oak production, we surveyed the horizontal and vertical distribution ranges of damaged oaks and depth of sites of overwintering larvae and quantified the amounts of biomass and acorn removed by the weevils on deciduous oak species. All of the endemic oak species in Korea were damaged by oak nut weevils in all of the study sites including Mt. Halla and Mt. Seorak. The upper limit of vertical distribution of damaged oaks by the weevils raried from 700 m to 900 m. Mostly their larvae were found in soil from 8.1 cm to 10.0 cm depth in winter. Percentage of annual net primary productivity($720g{\cdot}m^{-2}{\cdot}day^{-1}$) of oak species removed by the weevils was about 7%, which is higher than the percentage removed by all the herbivores in typical temperate forest(5%) and equivalent to that by all the herbivores in tropical forest. The predation percentage of annual acorn production by oak nut weevil was 27% in Q. mongolica and 33% in Q. acutissima. This results indicate that the branch-cutting behavior of oak nut weevil may be the most important factor regulating oak population and affecting other predators dependent on acorns.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.139-143
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• 1992

Feeding plants of rice water weevil(RWW) adult and larvae were observed. Thirteen families including 104 species were found as host plants of RWW adult, and 74 species of them were newly identified as its host. Thmedia triandra var. japonica, Luzula capitata, Agropyron tsukushiense var. ransiens, and Zoysiama crostachya were most favorable hosts of adult RWW. Host plants for larvae were 9 species of weeds including Cperus nipponicus, Eleccharis kuroguwa, Sagittaria trifolia, and Claviceps purpurea in the rice paddy fields.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.265-269
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• 1989

Effects of air-tighteness of packing material and aluminum phosphide fumigation on mortality of rice weevil were studied during rice storage. Air-tight storage of rice in sealed bag of 0.1mm PE film or sealed glass bottle reduced the deterioration of rice quality and killed all rice weevils after 60 days storage, while paper bag, PP bag and straw bag storage kept them alive. One tablet of aluminum phosphide in one cubic meter heap of rice packed in PP bag was sufficient to kill all rice weevil in it, when the heap was covered by 0.15 mm PE film during fumigation.

• The Korean Journal of Pesticide Science
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• v.14 no.3
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• pp.284-288
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• 2010

A series of experiments was carried out for selecting insecticides and determining proper spraying time to control pea weevil (Bruchus pisorum Linnaeus) in Jeonnam area. In the field trial two times spray with diazinon, carbaryl, imidacloprid, spinosad, etofenprox, clorpyrifos-methyl showed good control effect and threetimes spray showed the better control effect. The second spray (spraying on 10th of May) took the major role of insecticide effectiveness expression for controlling pea weevil. Further trial for selecting insecticides among organophosphates to control pea weevil in lab was conducted and every organophosphate insecticide tested was very effective to pea weevil even at the concentration of one forth of its recommending concentration.

• Korean journal of applied entomology
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• v.48 no.1
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• pp.45-51
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• 2009

This paper presents sequential sampling plans for evaluating the pest density based on complete counts from probe in a rice storage warehouse. Both maize weevil and Indian meal moth population showed negative binomial dispersion patterns in brown rice storage. For cost-effective monitoring and action decision making system, sequential sampling plans by using the sequential probability ratio test (SPRT) were developed for the maize weevil and Indian meal moth in warehouses with 0.8 M/T storage bags. The action threshold for the two insect pests was estimated to 5 insects per kg, which was projected by a matrix model. The results show that, using SPRT methods, managers can make decisions using only 20 probe with a minimum risk of incorrect assessment.

• Korean journal of applied entomology
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• v.1
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• pp.20-25
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• 1962

A. The increases moisture contents of grain at R.H $75\%,\; and\; 28^{\circ}C$ 1) The moisture contents of polished rice were $0.4\%,\; 1 \%,\; 3.3\%$ higher than control after 4weeks in which had been infested with 100, 200, 500 individuals of weevil at the beginning. respectively. 2) The greatest moisture contents of polished rice was $16.26\%$ for 500 individual infested grain and the lowest one was $14.86\%$ for the 100 individual weevil infested grain after 4 weeks. 3) The increases in moisture contents of grain were proportionally greater with the size of the weevil population. B. Changes in moisture contents of polished rice at the three levels of cylinder which contain 3kgs of grain and 1000 weevils were infested at the beginning of the experiment. 1) The moisture contents of the grain at all the levels of the cylinder which was not infested with weevil, were consistantly decreased in 12 weeks. 2) The moisture contents of the grain at all the levels of the cylenders which had been infested with 1000 weevils at the beginning of the experiment, were increased except top lovel, that were $15.6\%$ for middle, $41.55\%$ for the bottom levels after 12 weeks. 3) The moisture contents of the grain were greater toward bottom in both weevil infested grain and in control. 4) The moisture content increase might be caused by the respiration of the weevils and deterioration of the grain by microorganisms. 5) There were no tendency to confine the weevils at any definite levels, but as the deterioration of the grain goes on, the weevil moved to top levels of cylinders. 5) The decreases in moisture contents of the grain at the top levels of the cylinders might be caused by diffusion of water to the environment. 7) The differences in temperature at three levels of the cylinder from enviroment were little or negative in control but were greater and positive. and the bottom were higher than top in experimental cylinders. 8) The increases of temperature might be caused by the respiration of the weevil and microorganisms.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.914-917
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• 2001

The rice water weevil, Lissorhoptrus oryzophillus are major pests of aquatic rice plant throughout the country. In field, we examined efficacy of Steinernema carpocapsae and Xenorhabdus nematophilus against rice water weevil, Lissorhoptrus oryzophilus. Steinernema carpocapsae showed 71-74.2% mortality after 15days in the field. Also symbiotic bacteria Xenorhabdus nematophilus isolated from Steinernema carpocapsae showed 33.3-58.3% mortality after 15days at vat against rice water weevil, Lissorhoptrus oryzophilus.