• Applied Biological Chemistry
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• v.37 no.3
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• pp.148-153
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• 1994

Rice black-streaked dwarf virus (RBSDV), a member of the plant reoviridae fijivirus group, causes a serious damage for rice production in Korea. To characterize the RBSDV genome, virus particles were produced by feeding of planthopper (Laodelphax striatellus F.) carring RBSDV to maize plants for 2 days. In $30{\sim}40$ days after feeding, the viral particles were purified from the infected maize roots by using $10{\sim}40%$ sucrose gradient centrifugation. After treatment of 10% SDS to remove the viral coat proteins, ten viral double-stranded RNAs were resolved in agrose gel electrophoresis. Total dsRNA was then used to synthesize cDNA by reverse transcriptase and a cDNA library was constructed in the ${\lambda}gt11$ vector. The phages that contain RBSDV cDNA fragments were selected by hybridizing with the random-primed probe prepared from RBSDV dsRNAs. After subcloning of several cDNA fragments into the pUC19 plasmid vector, one clone (pRV3) was chosen for sequencing. The pRV3 clone was shown to be located on the RBSDV genome fragment No.3 by RNA gel-blot analysis. Sequence analysis of the clone revealed that the pRV3 contains two partial open reading frames.

• Parasites, Hosts and Diseases
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• v.34 no.1
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• pp.27-34
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• 1996

The geographical distribution and population density of rodents and chigger mites at six localities of Chollanam-do were investigated from October to December in 1993. Among total 142 field rodents collected by the modified Chemin wooden traps, 131 rodents were Aponemw usrari,us (92.3%) and 11 were Crocidurc losiurc (7.7%). Out of 142 field rodents, 92 were parasitized by chiggers, showing 69.0% of the infestation rate and 74.2 of the chiggor index. Infestation rate and chigger index of A. omfernrius and C. lusiurc were 73.3%, 80.4 and 18.2%, 0.5, respectively. From the trapped field rodents, 10,532 chiggers were collected and identified with 11 species of 4 genera. Leptotrombidium pcLLinun. the vector 3pecies of tsutsugamushi disease, was the dominant species, showing 8,038 chi99ers (76.31%). L. scutellnre was the second dominant species showing 1,359 chiggers (12.9%). The distribution of chigger mites was clearly localized by the species, showing the different dominant species according to localities. The predominant species was 1. scutellare (100%) in Changhung-gun, 1. scutellcre (41.5%) in Posong-gun, 1. pnllidum (88.8%) in Hwasun- gun, 1. pnLlidunl (59.2%) in Koksong-gun, 1. zetum (77.3%) in Hampyong-gun, and 1. pclpcle (63.4%) in Tamyang-gun. Regarding to the geographical distribution of chigger population density, the infestation rate and chigger index was most high in Hwasun-gun as 62.4% and 216.2 respectively, and next high in Koksong-gun as 22.4% and 77.7%, respectively.

• Korean journal of applied entomology
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• v.31 no.4
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• pp.396-415
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• 1992

To investigate identification of species distribution state, population density of plant parasitic nematodes and damaged state by parasitism of nematodes with soil samples taken from major cultivating area of medicinal herbs in Kyungbuk districts are summarized as follow; total species belonging to genera in families were identified from 43 different medicinal herbs. The dominant nematode species on medicinal herbs was Meloidogyne hapla by 55.6% of field infection. Damaged state by parasitizm of Root-knot nematode, M. hapla, M. incognita are severed 15 medical plant except P. japonica, infected field were in 54.5~88.0%, and highered in population densities of 2nd larvae, Gall, Egg sac. Percentage of yield-decrease were 57.8% in A. gigas, 49.1% in P.japonica. Lighten effect of M. spp. by cropping system were lowered in population density in Rice+Paeony than Paeony+Paeony in paddy field, and also lowered in Sesame+Paeony or one year fallowing after harvest Paeony than Red pepper+Pseony, Paeony+Paeony in upland field.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.305-308
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• 2013

This study was conducted to describe the external morphology of Platypus-koryoensis Murayama in immature stage, to determine each instar based on larvae head-capsule, and to measure individual and local variations in the number of mycangia of adult. Egg of P. koryoensis, had oval shape and lengths of the major and minor axis were $0.67{\pm}0.051$ mm and $0.41{\pm}0.053$ mm, respectively. Body colour of $5^{th}$ instar was gloss white with well-developed mandible. Larvae of P. koryoensis grew up to $5^{th}$ instar and each instar was clearly classified by head capsule width. Head capsule width for $1^{st}$, $2^{nd}$, $3^{rd}$, $4^{th}$, and $5^{th}$ instar larvae were $0.35{\pm}0.004$ mm, $0.45{\pm}0.010$ mm, $0.67{\pm}0.039$ mm, $0.94{\pm}0.069$ mm and, $1.12{\pm}0.007$ mm, respectively. The colour of pupa was pale yellow and its length was $4.64{\pm}0.044$ mm. The number of mycangia per female had individual variations from 5 to 12 and 83% of the adults had from 6 to 8 mycangia. There was no significant difference in number of mycangia collected from between Namyangju region and Honchen region.

• Korean journal of applied entomology
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• v.54 no.4
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• pp.419-423
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• 2015

Small brown planthopper (SBPH), Laodelphax striatellus, gives a lot of damage to the rice by insect vector of rice stripe virus (RSV). This study compared the RSV acquisition and infection rates according to wing form, sex, and life stage of SBPH. The RSV acquisition rate in macropterous and brachypterous was 60.7% and 63.1%, respectively. The RSV acquisition rate by sex was 61.9% in female and 52.2% in male. However, there was no difference in significance. The RSV acquisition rate of nymphs and adults was 51.2% and 58.7%, respectively. The RSV infection rate by wing form was 53.3.% in macropterous and 48.2% in brachypterous. According to life stage, nymphs was 38.2% and adults was 42.6%. There was no difference in significance. On the other hand, female and male of RSV infection rate was 50.5% and 22.3%, respectively. There was a significant difference. Additionally, developmental periods of SBPH by RSV infection, the longest when inoculated with RSV-infected SBPH in healthy rice, while the shortest when inoculated healthy SBPH in healthy rice.

• Korean journal of applied entomology
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• v.59 no.3
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• pp.209-215
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• 2020

Debates over the ecological and public health impacts of aerial pesticide sprays are increasing. This is particularly true for controlling Monochamus beetles, which are vector insects of pinewood nematodes. In 2017, adult female orb-web spiders, Trichonephila clavata, were sampled from pine forests in Yangsan-si, Gyeongsangnam-do, Korea, where the aerial pesticide spray, fenitrothion or thiacloprid, was used for several decades. The biological traits of the spiders (body weight, body length, carapace width, and total hind leg length) were compared among treatment sites (no-spray, sprayed three times, and sprayed five times), and differences were observed. The body length, carapace width, and total hind leg length of the spiders in the sprayed areas were significantly shorter than in the no-spray area, but there were no differences between the area sprayed three or five times. These results indicate that repeated exposures to an aerial pesticide spray can alter morphological parameters, which influences population-level fitness. Future studies should monitor the spider long-term responses to pesticides (a direct effect) and prey availability (an indirect effect).

• Sijohaknonchong
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• v.44
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• pp.255-279
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• 2016

Ignominy are ashamed or that mind. It is noted that this article 'shame[恥]' will do for obtaining the social dynamics in some way in the literary aspect. To investigate this aspect, this article took the text produced on the basis of 'shame[恥]' to be analyzed. First, through the Sayuksin[死六臣]'s Sijo[時調], 'Shame[恥]' they have confirmed the room to go to form a sympathy by revealing without hidden. It is worth evaluating in common with these Sijo is that of justice or loyalty. But the parameters of evaluation described what people are rare. In this article, I saw the parameter to 'shame[恥]'. Second, through the Sijo created in the war of the middle age of Chosun Dynasty, I examined the aspect of 'anger' which sparked a shame[恥]. Thus shame[恥] is hard to change the world directly. However, the possibility that it can also be a psychological instrument was found to be sufficient. In conclusion, 'shame[恥]' is clearly greater tendency to dismiss as a private act of the heart. But, I understood that the negative region of 'shame[恥]' can be converted to positive region. At this time, The premise of 'shame[恥]' should always be oriented to justice.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.528-533
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• 2010

Cage plots were established in 2008 to find the relationship between combination of tended Japanese red pine sapling and the habitation of Monochamus alternatus, a vector for pine wood nematode. Japanese red pine sapling tended at different times were successively put into the cage, and then the adult of Monochamus alternatus was put in June. Presence or absence of the larva was determined November. Sapling tendings were done at seven successive times in 2009, mid- and late February and March, mid-April, May and June. Some saplings were also tended in mid-October of 2008, the previous year of this experiment. The larva was found in all the saplings tended later than mid-March in 2009. No larva was found in the saplings tended in mid-October of 2008 and those in February of 2009. In case of the combination the by-products of mid-February and late March of 2009 and mid-October of 2008, the larva was found in the by-product of mid-February and late March of 2009, but those in mid-October of 2008 was not. When the saplings tended in mid-October of 2008 and mid- and late February of 2009 were put into the cage singly, the larva was found in all the saplings. Results indicated the mixture of the saplings tended at different times affected the habitation of Monochamus alternatus differently.

• Parasites, Hosts and Diseases
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• v.29 no.1
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• pp.67-86
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• 1991

In order to determine the seasonal prevalence and population dynamics of Culex tritaeniorhynchus in relation to the epidemics of Japanese encephalitis, and ecology of these vector mosquito in Kyungpook Province, Korea, studies were con- ducted during the Period of 7 years from 1984 to 1990. Cx. tritaeniorhynchus first collected in June between 4th and 28th, and trapped in large numbers during the period from mid-August to early September, showed a simple sharply pointed one-peaked curve. There was a gradual decrease from mid-September, with a very small number of them collected until early October in every year. The average number of Cx. tritaeniorhynchus rapidly decreased after 1985, and the number became particularly low in 1989. The highest population density, which was observed in August during the initial three years, was found to be delayed in the following years, accompanied by a decrease in the number of mosquitoes. In the trend of nocturnal activity of Cx. tritaeniorhynchus, with oncoming darkness they become very active, gradually decreasing in activity toward mid night, but slightly increasing toward dawn. The immature stages of Cx. tritaeniorhynchus were first found in rice fields contributing to peak adult densities in mid-July. The highest average densities of Cx. trisaeniorhynchus was 14,900 per m2 on mid-August 19th. The larval Cx. tritaeniorhynchus showed high resistance levels and resistance ratios against 5 organophosphorus compounds. In the adult horisontal life table characteristics of Kyungsan colonies of Cx. tritaeniorhynchus under insectary condi- tions, life expectancy was 28.3 days for males and 59.8 days for females. The net reproductive rate was 7.8 and generation time was 25.6 days.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.206-211
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• 2021

Hygienic behavior of Honey bees, Apis mellifera, was evaluated by uncapping and removing ability of dead broods from the nest. Hygienic behavior is originated from quantitative traits, which are expected to express key roles in colony defense against mite parasites and bacterial and fungal diseases. It is regarded as one of important characteristics of honey bee's resistance to parasites and pathogens. In this study, five inbreed and two hybrid lines of A. mellifera, the former five inbreed lines, which have been reared for over eight years at the National Academy of Agricultural Science in Korea, and the latter two hybrid lines, which have been bred by crossing between the inbreed lines, were investigated on their hygienic behavior by a pin-killed brood assay at 12hrs and 24hrs after treatment. The results indicated that after 12hrs one inbred line was proved to be hygienic (removal rate of dead brood >90%), three inbred and two hybrid lines showed intermediate behavior, and one inbred line belonged to non-hygienic (removal rate of dead brood <70%). However, after 24hrs, only one line was considered to be intermediate as removal rate was below 90%, thus all except this line had shown hygienic behavior.