• Korean journal of applied entomology
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• v.47 no.2
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• pp.133-139
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• 2008

This study was performed to investigate the immature development period, fecundity, emergence rate and sex ratio of Sclerodermus harmandi against different host insects, Monochamus alternatus, M. saltuarius and Psacothea hilaris. Full grown larvae and pupae of host insects were provided with foods. The mean larval period of S. harmandi female was $29.2{\pm}0.93\;and\;25.1{\pm}0.47$ days in larvae and pupae of M. alternatus, $27.1{\pm}0.41\;and\;26.0{\pm}0.69$ days in M. saltuarius, and $26.3{\pm}0.38\;and\;31.2{\pm}0.24$ days in P. hilaris, respectively. S. hilaris adults were emerged at $12.9{\pm}0.2$ days in female and $11.9{\pm}0.2$ days in male after pupation when hosted M. alternatus pupa. Development period in male showed shorter one day than in female. Success rate of oviposition against different hosts was higher as 98.6 and 97.5% on full grown larva and pupa of M saltuarius. Emergence rate was higher as 90.1 and 87.3% on M. saltuarius larvae and pupae. Sex ratio of emerged S. harmandi adults was approximately 10:1 (Female : Male), females showed higher emergence rate than males. The period until first oviposition after emergence in S. harmandi female was the shortest in $4.6{\pm}0.1$ days on M. saltuarius pupa. When three females of S. harmandi were inoculated on M. saltuarius larva, the number of laid eggs was the highest $62.7{\pm}2.5$ per female.

• Korean journal of applied entomology
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• v.52 no.3
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• pp.215-225
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• 2013

To assess the efficacy of nematicides for the control of plant-parasitic nematodes in fruit and vegetables fields, soil samples were collected from a cucumber field at Gongju; from strawberry fields at Buyeo, Nonsan, and Jinju; and from a melon field at Gocksung in Jeonnam Province, Korea. Plant-parasitic nematodes were separated from each soil sample and identified. The susceptibilities of the nematodes to abamectin 1.68% SC, cadusafos 3% GR, dazomet 98% GR, fosthiazate 30% SL and BA12011 SL were examined under laboratory and field conditions. The average population density of plant-parasitic nematodes was generally reduced after the treatment with nematicides; however, there was increase in the population of Pratylenchus spp. in soil after treatment with fosthiazate at Buyeo and Gocksung. Furthermore, there were increased populations following treatment with abamectin, cadusafos, and dazomet at Gocksung. The control effects of BA12011 treatment on plant-parasitic nematodes were confirmed to be similar to those of the other 4 nematicides evaluated, although its control effect was higher than that of fosthiazate in cucumber-growing soil at Gongju. The effects of nematicide treatment on egg mass formation in each of the collected soils differed according to the region of soil origin. Abamectin was effective in reducing the degree of egg mass formation in Buyeo and Jinju soil, whereas BA12011 was effective in Nonsan and Gocksung soil. Dazomet was found to inhibit egg mass formation in Gongju soil. To evaluate the effect of the newly developed nematicide, BA12011, experiments were conducted in a cucumber-growing greenhouse. The average population densities of Meloidogyne spp., Pratylenchus spp., and Helicotylenchus spp. after the first treatment were reduced to a greater extent than after the second treatment. It is thus suggested that early nematicide treatment is important for effective control of plant-parasitic nematodes.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.12
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• pp.1105-1112
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• 2009

Antibiotics are biologically active substances and commonly used for therapeutic treatment of infectious disease in humans and for treating and protecting the health of animals. In recent years, antibiotics have attracted worldwide attention because of their side effects on the environment. Consequently, efforts have been made to monitor the residual of antibiotics in the environment. This study tested the mobility of tetracyclines and sulfonamides in soil and leachate through column experiments. The three tetracycline antibiotics showed higher mass recovery rates in all kinds of soils(28.00~44.11%) than in leachate(10.54~27.43%). This seems attributable to the high adsorption coefficient values($K_d$) of tetracyclines representing strong and active adsorbability to organic and mineral phases in soil, ending up relatively small amount being detected in surface water. By contrast, the sulfonamides(sulfamethazine and sulfathiazole) showed higher mass recovery rates in leachate(23.19~26.20%) compared to in soil(10.41~14.21%) due to lower adsorption coefficient values and higher mobility of sulfonamides, enabling easier movement to surface water through the runoff in the environment.

• Research in Plant Disease
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• v.26 no.2
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• pp.72-78
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• 2020

Clover cyst nematode, Heterodera trifolii, is one of the most important plant-parasitic nematode on Kimchi-cabbage in highland in Korea. Recently, a demand of soil disinfection machine for fumigants is increasing. This study was conducted to assess the control effects of a newly developed prototype soil disinfection machine to the cyst nematode. Two fumigants, dimethyl disulfide (DMDS) and metam sodium (MNa), were treated using the machine in a field, which was infected with the cyst nematode. After 4 weeks, control effects of fumigants were assessed as eggs hatching rates inside of cysts extracted from the soil, and as a number of females reproduced in roots of Kimchi-cabbage. DMDS (39 l/10 a) suppressed over 99.0% of the eggs hatching rate and the number of females reproduced. On the other hand, MNa (29 l/10 a) controlled the egg hatching rates from minimum 78.3% to maximum 99.4%, and the number of females from 34.7% to 49.3%. The control effects of two fumigants to clover cyst nematode by treated depth were no significant differences statistically. These results showed that DMDS treatment using the soil disinfection machine was expected to have the control effects for the clover cyst nematode.

• Journal of Korean Society of Forest Science
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• v.96 no.3
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• pp.295-299
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• 2007

Resistance to chestnut gall wasp (Dryocosmus kuriphilus) of Korean prevailing chestnut cultivars, new cultivars released by Korea Forest Research Institute (KFRI), and local cultivars by growers was investigated to select optimal cultivars suitable for main chestnut producing areas. During three years investigated from 2004 to 2006, we could find no damage by chestnut gall wasp in any cultivars of test sites located in Gongju and Chungju of the central area. However, most cultivars of Gwangyang, Sancheong and Hapcheon sites located in the southern area showed a lot of damage by chestnut gall wasp. Hapcheon was most severe in comparison with regional damage by chestnut gall wasp. From comparison among cultivars, Kwangeun, Sandae, Eunsan and Idae released by KFRI showed no damage suggesting the highest resistant cultivars. On the contrary, over 20% in total damage by chestnut gall wasp was investigated in Tanzawa, Riheiguri, Kurakata-amaguri, Pyeonggi, Gwangdeok, Seil, Sinipyeong and Yumabyuni suggesting susceptible cultivars. In damage by chestnut gall wasp according to investigated position within tree, weak shoot was more severe than bearing shoot. Damage by chestnut gall wasp of major cultivars in Gwangyang, Sancheong and Hapcheon sites was remarkably decreased in 2006, and it seems to be caused by biological control by natural enemies such as Torymus sinensis.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.93-99
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• 1999

We investigated the effect of constant photoperiod (16L : 8D, 12L : 12D, 8L : 16D), on the oviposition, parasitism, and emergence of Trichogramma dendrolimi. Also during 16L : 8D condition circadian, oviposition and emergence of this species on artificial eggs were checked every 2hrs. When twelve eggs of Antheraea pern~i and artificial eggs were provided, the wasps had the highest rate of oviposition in the first day, and decreased dramatically there after. In these different photoperiod, the total oviposition numbers per A. pernyi eggs by the wasp were 161.8 in 16L : 8D, 145.8 in 121 : 12D and 128.5 in 8L : 16D respectively in the first day. On the other hand for the artificial egg in 16L : 8D photoperiod, the total oviposition number per egg was 106.8 in the first day, 26.6 in the 2nd day and 21.3 in the 3rd day. The rate of emergence from A. pernyi eggs was not different depend on wasp's day age, however in the artificial eggs, after the first day's 84.7% decreased considerably. The emergence rate from artificial eggs was the highest comparatively between 04:OO-0600 hours.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.87-95
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• 2018

Nosema spp. (NS) causes severe problems to honey bee colonies including the death of the highly infected ones. Searching for effective materials to control this parasite is very important. The objectives of this study were to identify the calendar for the prevalence of NS and other bee diseases, and to test the efficacy of three materials: diluted honey mixed with lemon juice (M1), chamomile extract mixed with sugar syrup (M2) and sutrivet mixed with sugar syrup (M3) against Nosema. To realize these objectives, diseases of brood and adult honey bees were surveyed over one year. Also, the efficacy of M1, M2 and M3 against Nosema was evaluated under field and laboratory conditions. The results showed that few diseases for immature and mature stages of honey bees were recorded. NS was detected during winter and spring in link with low temperature and high relative humidity. Under field conditions, M2 reduced the infection by 36.66% while M3 by 23.33% and finally M1 by 13.33%. In the laboratory, the highest efficacy was to M2 followed by M1 and finally M3. The three materials impacted the percentage of survived bees significantly higher than infected bees without any treatments over the experimental period. The study suggests the potential role of chamomile as a natural material to control NS.

• Parasites, Hosts and Diseases
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• v.27 no.1
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• pp.47-56
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• 1989

Some biological characteristics of Centrecestus armatui were studied using albino rats as its experimental host. The metacercariae were collected from Zacco Platypus by artificial digestion method. Laboratory rats(Wistar) were fed each 100 or 200 metacercariae and sacrificed on 1, 2, 3, 4, 5, 6, 8, 14 and 28 days after infection to recover worms of various ages. The average recovery rate was 10.7% from 82 rats. The rate decreased rather slowly for the first 8 days but showed a steep decrease thereafter. Of the worms, 35.5% were recovered from the duodenum and 62.5% from the jejunum. At metacercarial stage, body length was $293{\mu\textrm{m}}$ and body width $144{\mu\textrm{m}}$. At adult stage, the length and width reached $382{\mu\textrm{m}}$ and $214{\mu\textrm{m}}$ respectively at 14 days after infection. The testes and Mehlis' gland were recognized at metacercarial stage, whereas the ovarian anlage appeared on the 1st day of infection, seminal vesicle and vitellaria on the 2nd day, and seminal receptacle and uterine eggs on the 3rd day. Until 8 days after infection the genital organs developed continuously and the number of uterine eggs increased. The above results show that albino rats are one of useful experimental hosts for C. armatus and the worms can develop to adults in 3 days after infection.

• Korean Journal of Veterinary Research
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• v.27 no.1
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• pp.101-108
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• 1987

A total of 213 rabbits was investigated from July 1981 to June 1986, for the survey on the incidence of Cysticercus pisiformis infections and the morphological characteristics were observed for the descriptions on the scolexes of the cysts collected. The results obtained were summarized as follows; The overall infection rate was revealed as high as 21.6% and it increased annually with the secular trend equation Y=7.45X+5.87 when, Y=infection rate estimated, X=year 0(1981) to 5 (1986). The incidence was no relation with the sexes of the host, but it was higher in the short-haired New Zealand White than in the long-haired Angola. It was also revealed that the liver was the most parasitized organ (39.1%) and that 48 cases were double infections in two organs, such as the mesentery, the stomach or the kidney. The mean size of the cysts measured was 7.04mm in length and 4.62mm in width. There were four suckers and a rostellum on the top of the scolex identified inside the cyst. The hooks were arranged in two rows, the large-type inner hooks (mean $250{\mu}m$ in length) and the small-type outer hooks (mean $150{\mu}m$ in length).

• Journal of Life Science
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• v.19 no.11
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• pp.1499-1505
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• 2009

This study was carried out between August and September 2007 to determine the causative agents and epidemiologic features of rabbit dermatitis in Korea. Rabbits were shipped to the laboratory in the College of Veterinary Medicine from 10 rabbit farms. A total of 520 hair, blood, and skin specimens collected from skin lesions of 40 rabbits with suspected dermatopathy were examined mycologically, bacteriologically, and parasitologically. The positive rates of dermatophytosis, bacterial skin dermatitis, and ectoparasite dermatitis were 95, 92.5, and 7.5%, respectively. The etiologic agents of dermatophytosis were identified as Trichophyton mentagrophyte (95%), non-dermatophytic filamentous fungi such as Aspergillus s(5%), and Cryptococcus humilocus (2.5%). With respect to bacteria-related skin dermatitis, Staphylococcus coagulase negative was the most common etiological agent. Staphylococcus aureus was the second most frequent causative agent. Most of the pathogenic isolates were resistant to tetracycline, and aminoglycosides such as amikacin and gentamicin were the most effective drugs against the pathologic bacteria isolated. Ectoparasites were rarely detected in this study. Only Psoroptes cuniculis was detected in 3 (7.5%) out of the 40 tested rabbits. The role of ectoparasites as a causative agent of dermatitis in rabbits in this study was minimal. Our results provide important information related to rabbit dermatitis treatments and researches.