• Korean journal of applied entomology
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• v.39 no.4
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• pp.251-258
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• 2000

These studies were conducted to investigate the prey consumption and suppression of cotton aphid and green peach aphid by Chrysopa pallens Ramber as a predator. The 3$^{rd}$ instar of C. pallets fed on 29.8, 77.9, 133.6, and 155.7 individuals of apterous Aphis goussypii Glover a day at 17,22, 27, and 32$^{\circ}C$, respectively. A preovipositing female fed on 73.1 individuals, ovipositing female on 86.6 individuals, and adult male on 69.7 individuals of apterous Myzus persicae (Sulzer) a day at the 27$^{\circ}C$. The functional response curve of the larvae and adults of C. pallens to the densities of A. gossypii indicated Helling’s Type II: the consumption of prey by the C. pallens increased with the prey density but the consumption rate decreased. The attack rate of 3rd instar of C. pallens was the highest among the 2nd instar, 3$^{rd}$ instar, adult male and adult female, and handling time was the shortest. The critical ratio of the predator vs. the prey to effectively suppress the population of A. gossypii by releasing C. pallets eggs was 1 : 4 on red pepper and egg plant, and 1 : 3 on cucumber. Release of second larval stave of C. pallens at the ratio of 1 : 30 of the predator vs. the prey controlled satisfactorily A. gossypii on red pepper, and 1 : 20 on cucumber and tomato. The three-times introduction of the eggs of C. pallens was as effective as four applications of insecticides from mid-June to late September.r.

• Korean journal of applied entomology
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• v.45 no.2 s.143
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• pp.145-152
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• 2006

Predation of Neoseiulus fallacis was observed for biological control of Panonychus citri that is one of the major insect pests on citrus. The daily predation of development stages of P. citri by an adult female of N. fallacis were 20.1 eggs, 26.1 larvae, 18.2 protonymphs, and 7.4 deutonymphs at 25$^{\circ}C$, The daily predation of P. citri eggs by N, fallacis was observed under different temperatures. The predation was increased as the temperature rise. At this time, ratio of eggs production of l! fallacis after predation of P. citri eggs (number of eggs N. fallacis/number of eggs P. citri consumed by N. fallacis) was 0.09. The daily predation of P. citri eggs by N, fallacis was 21.1, 17.3, and 16.7 on the different arenas (diameter: 20, 40, and 60 mm), respectively. The predation was decreased as the arena of the leaf increase. The functional response of M fallacis to P. citri showed Holling's Type II response: the consumption of prey by N. fallacis increased as the density of prey increase but increasing rate was gradually reduced. As the result, it seemed that N. fallacis can be use for biological control of P. citri.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.3
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• pp.257-264
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• 2011

On April 20, 2010, semi-submersible offshore drilling unit Deepwater Horizon was exploded and sank, and 4.9 million barrels(about 778 thousand tons) of crude oil was spilled into the Gulf of Mexico. As more than one year has been passed since the incident, a lot of investigation reports and lessons learned have been made public and also a lot more will be released soon. This paper studies the final report of the National Commission on "the BP Deepwater Horizon Oil Spill and Offshore Drilling", which was organized by the executive directive of U.S. President Barack Obama, and the interim report of Joint Investigation team of U.S. Coast Guard and BOEMRE of "Report of Investigation into the Circumstances Surrounding the Explosion, Fire, Sinking and Loss of Eleven Members Aboard the Mobile Offshore Drilling Unit Deepwater Horizon". The review is focused on the response to the oil spill. And the paper suggests how to improve national marine pollution response policy. In the paper, the Korean governments is suggested to reinforce the capability for instructing and supervising the responsible party's source control measures, to review how to introduce in-situ burning and vessel of opportunity program into our country, and to continue monitoring on the progress of developments of R&D projects related to oil spill response in the U.S..

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.437-445
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• 2017

An analysis of recent studies and a field survey were conducted to investigate the distribution of the exotic species Ophraella communa LeSage (Coleoptera, Chrysomelidae) and the results' applicability for biological control against ragweed, which disturbs the island's ecosystem. The ragweed beetle (O. communa) can be found anywhere on the host plant Ambrosia artemisiifolia L., which grows in Jeju Island. Moreover, ragweed beetles possess the following characteristics: a high host plant specificity, a high-temperature resistance, an excellent mobility, and multivoltinism. Ragweed is extensively distributed and gradually expands its habitat further on Jeju Island. For this reason, it is recommended to take advantage of O. communa for the biological control of ragweed instead of pesticides or direct removal, considering that Jeju is endowed with many natural reserves and unique insular traits.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.91-100
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• 2022

Ticks are the arthropod vector capable of transmitting diverse pathogens, which include bacteria, viruses, protozoan and fungi. Ticks are able to survive under stressful environmental conditions. One of evolutionary outcomes of these obligatory hematophagous arthropods is the survival for extended periods of time without a blood meal during off-host periods. Water conservation biology and heat tolerance have allowed ticks to thrive even under high temperatures and low relative humidity, thus they have become highly successful arthropods as they are distributed globally. Tick osmoregulatory physiology is a complex mechanism, which involves multiple osmoregulatory organs (salivary glands, Malpighian tubules, hindgut and synganglion) for the acquisition and excretion of water and ions. Blood feeding and water vapor uptake have been early reported as the primary passages for ixodid tick to acquire water. Recently, we have learned that ticks can actively drink environmental water allowing hydration. The acquired water can be traced to the salivary glands (type I acini) and the midgut diverticula. This opens new avenues for tick management through the delivery of toxic agents into their drinking water, in addition to an alternative strategy for the study of tick physiology. Here we address the osmoregulatory physiology in the ixodid ticks as a potential target physiological mechanism for tick control. We discuss the implications of water drinking behavior for tick control through the delivery of toxic agents and discuss the dermal excretion physiology as an additional pathway to induce tick dehydration and tick death.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.356-369
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• 1985

In Korea, inevitable researches for the blast control exactly started from 1927 by the organization of Office of Rural Development with the local extensive outbreak of panicle blast at Jeonlla Buk-Do Province in 1926. At present, the rice blast is still one of the most destructive and widespread diseases in spite of considerable contributions by rice scientists, particularly plant pathologists during last 55 years in Korea. Rice blast control and management are very difficult because of the marked variability in pathogenicity of the blast fungus. From the results obtained through the disease surveys during last 70 years, different 3 prevalence type of blast such as bimodal leaf-blast type, bimodal panicle-blast type and bimodal continual blast type were recognized. In generally speaking, pattern of blast outbreak is said to be characterized by severe outbreak of panicle blast after slight outbreak of leaf blast with discontinuity between leaf and panicle blast. So we have to pay much attention for successful management of panicle blast giving direct influence to rice yield. Main factors induce blast epidemic were pointed out to be breakdown of the disease resistance, nutritional unbalance such as excess application of nitrogen, delay of transplantation and longspell of rain fall by extensive surveys and researches on blast during last 70 years in Korea. The fact some of Japonica varieties such as Kokuryomiyako, Tamanishiki, Ginbozu and Pungok belong to varietal group A had been cultivated with extensive acrage over 30 years in this country should be mentioned by Korean rice scientists. Differences in field resistance between varieties in the same group are detectable and apparently small but sometimes epidemiologically significant differential effects may be found out in case of blast. Much more attention should be payed to accumulate the knowledges on field resistance for successful management of blast. Excess application of nitrogen is more effective to outbreak of panicle blast than that of leaf blast of IR varieties. In comparatively low level application of nitrogen infection rate of panicle blast of IR varieties is considerably high. Low temperature effects on outbreak of blast is very great. It results in remarkable increase of the inoculum potential on the leaf lesions and infection of panicle blast in leaf sheathes of IR varieties during the booting stage. In economic point of view, it is concluded that 5 times sprays of effective fungicides including 3 times before and 2 times after heading is good enough to control blast. We have experienced no one of control measures for blast is superior to all others. The integrated control measures was established as guideline of blast control around 1950 in Korea. This guideline must be helpful for rice growers as long as rice growing continue.

• 한국해양학회지
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• v.26 no.4
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• pp.324-331
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• 1991

Laboratory experiments were undertaken in mixing chamber to study the water-in-oil emulsion formation tendency, stability and formation rate of 16 crude oils. Arabian, Iran, Dubai, Isthmus and Daekyung crudes showed high emulsion formation tendency and had water contents of 80-90%. Emulsions of crude oils of middle East were very stable, while Isthmus and Daekyung sudes formed unstable emulsion. Emulsion formation tendency rate, and stability showed significant correlations with asphaltene content of crude oil. To evaluate the possibility of preventing mousse formation, inhibition ability of several dispersants and demulsifier was tested. They inhibited mousse formation at 0.1-0.2% concentrations (v/v). Emulsion inhibition by chemical treatment delayed the time of formation, but did not decrease water content. Demulsifying ability of dispersants and demulsifier was tested because biscous emulsion causes formidable problems in skimming, pumping and recovery operation. British demulsifier Alcohol 0 showed excellent emulsion breaking efficiency at 0.1% of emulsion Vol..

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.380-387
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• 2016

This study was performed to select potentially available biological control agent from soil bacteria for prevention of ginseng damping off. More than five hundred strains were isolated from ginseng rhizosphere soil. By testing antifungal activity, we have selected three soil bacteria strains and their ability to produce antibiotics and lytic enzymes such as cellulase, protease and pectate lyase was examined. Also, the presence of genes for biosynthesis of lipopeptide such as fengycin, bacillomycin D, surfactin, iturin A, and zwittermicin A was investigated in selected strains. All three strains produced cellulase, protease, and xylanase. Moreover, these strains had gene for biosynthesis of bacillomycin D, surfactin, and iturin A. ES1 and ES3 strains were identified Bacillus methylotrophucus and ES2 was confirmed Bacillus amyloliquefaciens using phylogenetic analysis on the basis of 16S rRNA gene sequences. In field test, control value of ES1, ES2 and ES3 treatment was 32.4%, 46.8% and 36.7%, respectively. This results indicate that antagonistic microbes with high ability of antifungal and lytic enzyme activity can be used as a useful biological control agent to control ginseng damping off.

• The Korean Journal of Mycology
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• v.17 no.1
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• pp.39-47
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• 1989

Among 100 species in 54 families of plants tested, leaf extracts from Allium cepa, Allium sativum, Malussieboldii, Reynoutria japonia and Rheum coreanum were inhibitory on mycelium growth of phytophthora spp.. Especially, Allium sativum and Malus sieboldii were strongly inhibitory. Allium sativum, Malussieboldii and Rhem coreanum were strongly inhibitory on zoosporangium germination of P. capsici. Malus sieboldii only were strongly inhibitory on zoosporangium germination of P. nicotiana and P. infestans.And Malus sieboldii were strongly effected on disease control of these pathogens. These results indicate the possibility of finding antagonistic plants in the nature for the control of certain pathogens in soil.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.111-115
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• 2000

Fifty-two nematode predatory fungi were isolated from 37 soil samples collected from eight provinces in Korea. Isolated fungi were tested their predacity against Rhabditis sp. and Meloidogyne incognita in petri dish, and against M. incognita in greenhouse pot experiments. Fifty isolates had trapping organ of adhesive networks and two isolates had adhesive column or adhesive knob. In petri dish experiments, 5 1 isolates against Rhubditis sp. and 26 isolates against M. incognita showed over 91 % of predacity; in greenhouse experiments, however, only three isolates showed over 81% of predacity. These results imply that the results from the laboratory experiments are not consistent with those from the greenhouse experiments. Therefore, to select a promising biocontrol predatory fungi for plant-parasitic nematodes, the screening experiment should be conducted in conditions close to nature.