• Korean journal of applied entomology
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• v.55 no.4
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• pp.489-494
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• 2016

Biological control of the fungus gnat Bradysia difformis by the predatory mite Hypoaspis aculeifer was examined in hydroponic systems of strawberries in Namwon and Hapcheon varieties of Jeollabuk-do and Gyeongsangbuk-do provinces, respectively, from 2012 to 2013. The damage to strawberries caused by B. difformis was examined in seedling stages and during cultivation periods. To achieve environment-friendly management of B. difformis, 60.6 individuals of H. aculeifer were released per square-meter three and four times during cultivations periods of the Namwon and Hapcheon strawberry varieties, respectively. H. aculeifer had better control efficiency against of B. difformis than that observed with conventional cultural practices. Wilt symptoms and damage of strawberries due to B. difformis were decreased by approximately 7.4-10.4%.

• Korean journal of applied entomology
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• v.25 no.1 s.66
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• pp.1-9
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• 1986

Periodical samplings were made in the fields, located Hwasong-Gun, Banwal-Myon, Doondai-Ri, for two years to study the major factors responsible to the population of the overwintered pine needle gall midge, Thecodiplosis japonensis Uchida et Inouye. The population densities of the overwintered larvae reduced greatly at the time of pupation and the changing patterns seemed to be influenced by environmental conditions. The estimated 50% pupation day was about two weeks earlier for the 1980 generation compared with the 1979 generation, and much higher average and the daily maximum temperatures in 1981 affected on the development of the larvae. The relative emergence rates were 14.1% for 1979 and 14.9% for 1980 generation. The relative emergence rates(Y) were affected by the moisture contents of soil ($X_1$) and its variance $(X_2),\;Y=-68.41+4.3206X_1-0.6887X_2$. The relative emergence rates seemed to be decreased with the increased variance of the moisture contents of soil. Percents of needle gall were 49.63% for 1980 and 86.87% for 1981 generation.

• Parasites, Hosts and Diseases
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• v.23 no.1
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• pp.139-150
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• 1985

In order to determine the seasonal prevalence and population density of vector mosquitoes in Kyungpook Province, a survey based on average numbers of female mosquito per trap-night, were carried out during the period from May to November in 1984. Among the 34, 571 mosquitoes collected in Kyungsan county in animal shelters and human dwellings by light traps, approximately 45.0 per cent were Culex tritaeniorhynchus, 34.0 per cent Culex pipiens pallens, and 19.0 per cent Anopheles sinensis. By comparison, distribution of mosquito species in Ankang town, in which Japanese encephalitis had been reported in the past, were quite different and A. sinensis was the most abundant species, being constituted in 75.8 per cent, followed by C. tritaeniorhynchus(23.2 per cent), and C. pipiens pallens(O.6 per cent). In the general pattern of seasonal prevalence, C. tritaeniorhynchus first appeared in mid-June, and trapped in large numbers during the periods from mid-August to early September, showing a simple sharply pointed one-peaked curve, while C. pipiens pallens was found to be active through almost the entire season showing irregular curves with several peaks. The trend of seasonal distribution of A. sinensis was similar to that of C. tritaeniorhynchus, but the earliest dates of appearance and disappearance differed from that of C. tritaeniorhynchus. The results of hourly catches of mosquitoes by human baited traps have clearly shown the differences in the biting rhythm among the vector mosquitoes of this Province, such as the facts that C. tritaeniorhynchus and A. sinensis are rather constantly active all through a night with more or less inconspicuous peaks twice a night, while C. pipiens pallens exhibits an irregular curve, and the numbers of A. vexans nipponii, C. vagans and Armigeres subalbatus are very small and are not sufficient for estimating the biting rhythm. Four genera and fourteen species of larval mosquitoes collected from eighteen kinds of habitats which classified according to the categories followed by Bates (1949). The main breeding sites contributing to peak C. tritaeniorhynchus adult densities in this surveyed areas were evidently ricefields, ground pools, puddles and swamps and marshes, etc. Summarizing the results, this study indicated that the highest population density of C. tritaeniorhynchus was encountered in late August and early September, showing a simple sharply pointed one-peaked curve.

• Applied Microscopy
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• v.35 no.1
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• pp.41-56
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• 2005

Present study was performed to observe the tegumental ultrastructures by the developmental stages which derived from the experimental life cycle of Spirometra erinacei in laboratory conditions. In SEM view, coracidium was spherical in shape with numerous cilia, and its surface was covered with long cilia, tuberclelike projections with millet-like processes, and small holes. The body surface of procercoid was covered with numerous pointed microtriches except that of frontal pit with stout spine-like ones. However that of cercomer was covered with somewhat sparse blunt-tiped microtriches. Plerocercoids of 3 days old resembled the mature procercoid in shape, and their frontal pits were covered with numerous stout spine-like microtriches. However frontal pit and body surface in more than 5 days old ones were covered with conoid microtriches. On the surface of adult scolex, hairly long filamentous and stout short microtriches were mixedly distributed. Filamentous microtriches were more densely distributed in the anterior portion than in the posterior of scolex. The neck and immature proglottid were covered with only stout short conoid microtriches. In TEM view of coracidia, embryophore and oncosphere were obviously distinguished. The embryophore contained numerous glycogen particles, mitochondria and lipid granules. The cilia on the surface of embryophore rooted in the coracidial sheath, and consisted of 9 pairs of microtubules and 2 core complex. The oncosphere was covered with a thin and unarmed tegument, and was multi-nucleated. The protoplasmic layer of procercoid and plerocercoid consisted of disc-shaped bodies, vacuoles and mitochondria. Their tegumental cells commonly retained a nucleus, granular endoplasmic reticulums and secretory granules. The protoplasmic layer of plerocercoid was more compacted than that of procercoid. From the above results, it was confirmed that the tegumental ultrastructures are something different according to the developmental stages of S. erinacei.

• Korean journal of applied entomology
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• v.48 no.2
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• pp.229-236
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• 2009

Cage experiments by artificial infestations with different initial densities of Frankliniella occidentalis were conducted to analyze damages and develop control thresholds of F. occidentalis on greenhouse eggplant in 2005 and on greenhouse sweet pepper in 2007. In the eggplant experiment, the infestations of F. occidentalis resulted in direct damage on fruit surface and non-marketable fruits which had several thin or thick lines or bleaching patches on the surface. F. occidentalis adults were frequently found on the flowers of eggplants, while nymphs were mainly observed on leaves. The fruit yield of eggplants was not significantly different among experimental plots with different initial density of F. occidentalis. Relationship between % non-marketable fruits among harvested fruits of eggplant and sticky trap catches of F. occidentalis (no. thrips/trap/week) at two weeks before the harvest showed a positive correlation. Using the estimated relationship, the control threshold of F. occidentalis on greenhouse eggplant was estimated at 10 adults per week at two weeks before the harvest when 5% of non-marketable fruit was applied for the gain threshold. In the experiment of sweet pepper, the direct damage by F. occidentalis was observed on the fruit surface and calyx, and the marketable grade of the damaged fruits decreased. The significant yield loss of marketable fruits was found in plots with high initial introduced-densities. There was a high relationship between thrips density and percentage of damaged fruits. Assuming 5% yield loss (non-marketable fruit) for the gain threshold, the control threshold of F. occidentalis on greenhouse sweet pepper was 4.8 adults per trap and 0.9 individuals per flower at two weeks before harvest.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.170-174
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• 2010

The acaricidal activity of cyenopyrafen on the tea red spider mite, Tetranychus kanzawai was evaluated in laboratory and field studies. In the laboratory, cyenopyrafen was highly effective against egg, larva, protonymph and adult female of T. kanzawai. In surviving adult females of T. kanzawai exposed to cyenopyrafen, we observed significant reduction in reproduction and no egg hatch. Effectiveness of cyenopyrafen against adult female of T. kanzawai on bean leaves was lasted for 15 days at treatments of 125 and 83.3 ppm. In a field study, cyenopyrafen exhibited excellent activity to mixed developmental stages of T. kanzawai. Based on the results, cyenopyrafen could be used for the control of T. kanzawai and treatment of this acaricide at 83.3 ppm was recommended as the field rate.

• Journal of Environmental Science International
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• v.30 no.2
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• pp.191-194
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• 2021

This study aimed to provide information and data for the management of insect breeding farms by identifying the appropriate density when rearing Protaetia brevitarsis larvae. The breeding box of the insects was filled with 2 L of fermented sawdust on a 50 × 35 × 15 cm sheet of plastic, and the density of the treatments was 200, 300 and 400 P. brevitarsis in the first, second, and third larval stages. Each treatment was repeated five times, and the sawdust medium was replaced three times (10 intervals). The experiments were conducted for a total of 30 days from March 1, 2020. Overall, 200 P.brevitarsis in the first, second, and third larval stages reared in the breeding box had a higher average survival rate and lower average mortality rate, thereby contributing to efficient production. In conclusion, this result suggests a way to increase production efficiency through the environmental management of insect breeding farms.

• Korean Journal Plant Pathology
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• v.2 no.3
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• pp.199-206
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• 1986

Penetration level, female development and histological changes in infected root tissues were investigated following inoculation with different inoculum levels (110,440 and 1760 juveniles/plant) of Heterodera glycines (SCN) race 3 on susceptible 'Lee' and resistant 'Pickett' soybean cultivars. Penetration level was lower in Pickett at the higher inoculum levels but no differences were detected in Lee. However, the lower penetration level in the resistant soybean cultivar appeared not to be directly related to plant resistance (female maturation). The number of females recovered from Lee was lower at the highest inoculum level. The number of females maturing on Pickett was much less than that on Lee, showing that changes of SCN population is associated with the number of SCN maturing rather than nematode penetration. In Lee mono-infection sites (a single nematode per site) syncytia had dense cytoplasm and no central vacuoles. while multi-infected sites (many overlapping nematodes per site) had syncytia with a large central vacuole and many small vacuoles. Resistant responses in mono-and multi-infected root tissues of Pickett were delayed and rapid necrosis, respectively. The differences in tissue response are suggested as a mechanism that controls density-dependent population changes in resistant and/or susceptible soybean cultivars.

• Korean journal of applied entomology
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• v.56 no.3
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• pp.267-273
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• 2017

To protect plants from damage caused by Panonychus citri (McGregor), practical methods for the use banker plants have been developed to provide a habitat and augment natural enemies of several agricultural pests. The average population density of predatory mites on an Oxalis corniculata (creeping sorrel) sod culture was significantly higher (three times) than that on normal sod culture. Furthemore, the average population density of spider mites on creeping sorrel sod culture was significantly lower (3.7 times) than when weed control was practiced. Average consumption of the eggs and females of Tetranychina harti (Ewing) by Neoseiulus californicus (McGregor) females was approximately 1.96 eggs and 1.93 females per day, respectively. Phytoseiulus persimilis AthiasHenriot females never consumed T. harti. However, total development time of T. harti from egg to adult on O. corniculata was 17.4 days, and hatchability and survival rate were 77.5% and 84.8%, respectively.

• Biomedical Science Letters
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• v.2 no.1
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• pp.1-12
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• 1996

Antigenic components reacting with IgE and IgG antibodies were localized in muscular layer of adult and of larva, sparganum. But the antigenic components inducing IgG were localized at tegument and parenchyma in addition to muscular layer in adult and sparganum. Also in sparganum, the surface of calcareous corpuscles of parenchyma showed immunoreactivity to IgG antibody. However antigenic components inducing IgE antibody were not localized in tegument and parenchyma, but in adult worm, we observed the immunopositive reaction at the lining of vitelline follicles in mature proglottis and on surface of egg shell within uterus of graved proglottis. By the method of immunogold-labelling, we observed the location of antigenic particles in tegument of sparganum. The density of antigenic particles inducing IgG was higher than that of antigen particles inducing IgE in syncytial tegument, tegument cells. A total of 43 and 36 protein bands were resolved from crude extracts of adult and sparganum, respectively, by SDS-PAGE. 34 bands from crude extracts of adult and larva were migrated to same positions. By EITB, 21 bands of 44 bands in adult were recognized with IgG antibody, and also 21 bands of 36 bands in sparganum. 13 bands of them were common antigenic components both in the adult worm and sparganum. Because 19 bands of 44 bands in adult worm were reacted with IgE antibody, they were IgE antigenic component. In sparganum, 13 bands were IgE antigenic components. 9 bands of them were common antigenic component inducing IgE antibody in both a-dult and sparganum. 3 bands of antigenic component recognized by IgE and IgG antibody were nonspecific antigen in both adult and sparganum of Spirometra erinacei.