• Korean journal of applied entomology
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• v.34 no.4
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• pp.295-299
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• 1995

This study was conducted to find the control methods, status of overwintering and seasonal occurrence of Erioccoccus largerstroemiae on persimmon trees in Ch'ondo area, Kyongbuk province in Korea. Usually, overwintering eggs were sheltered in bark, among them the rate of alive eggs was 28.7%. The activiation of garpe-myrtle scale showed from late April, and they have three generations per year. The first occurrence of larval stage of Erioccoccus largerstroemiae starts from late June to early July, the second occurrence begins from middle August to late August, and from late June to early July, the second occurrence begins from middle August to late August, and from middle September to late September is the third, thus, three peaks of occurrence revealed in early July middle August, and late September respectively. Average number of eggs conceived in female adult was 229.3. Spray effect of chemical control showed as follows; lime sulfur with tow applications of pesticides (late June, late August) at 97.8%, machine oil with tow applications of pesticides (late June, late August) at 96.8%. And during the growing period, the spray results using three applications of pesticide only (late June, late August, amid September) showed 77.2% in field condition.

• Korean Journal of Agricultural Science
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• v.41 no.1
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• pp.23-27
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• 2014

Potato late blight occurrence is caused by various environmental factors, and the progress can be regularly predicted so that several predictive models have been developed. The models predict the timing of the disease occurrence, but they do not include the methods of the disease control. Effective fungicide control, economic threshold, prediction models were investigated in the study to reflect on customized control modules for the model forecasting the occurrence of potato late blight.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.361-368
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• 2022

This study seeks to determine the research trend of late adolescents by utilizing big data. Also, seek for research trends related to activity participation, treatment, and mediation to provide academic implications. For this process, gathered 1.000 academic papers and used TF-IDF analysis method, and the topic modeling based on co-occurrence word network analysis method LDA (Latent Dirichlet Allocation) to analyze. In conclusion this study conducted analysis of activity participation, treatment, and mediation of late adolescents by TF-IDF analysis method, co-occurrence word network analysis method, and topic modeling analysis based on LDA(Latent Dirichlet Allocation). The results were proposed through visualization, and carries significance as this study analyzed activity, treatment, mediation factors of late adolescents, and provides new analysis methods to figure out the basic materials of activity participation trends, treatment, and mediation of late adolescents.

• Korean journal of applied entomology
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• v.44 no.4 s.141
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• pp.337-339
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• 2005

In Iksan, Korea, Parnara guttata Brener et Grey spend three generations per year, 1st generation adult emerged mid to late May from pupa developed from overwintered larva in weeds on bank around rice paddy field or on hillside and moved to rice paddy field to lay eggs on leaves of rice. The damage to rice by 2nd generation larva began to increase late July and reached peak from mid to late August. The 3rd generation adults were observed early to mid September and flew away from rice paddy field. There was significant relationship between the transplanting time and the occurrence of P. guttata in rice paddy fields. P. guttata preferred the rice transplanted in late season in paddy field. Insecticide treatment on late July about a week before the peak larval occurrence reduced the damage by P. guttata up to 91.2%, whereas the treatment on early August was a lot less effective reducing only 57.2% of the damage.

• Journal of the Korean Society of Tobacco Science
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• v.5 no.1
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• pp.11-17
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• 1983

The tobacco moth, Ephestia elutella Hubner (Lepidoptera: Pyralididae), was first reported one of the serious of stored tobacco in Korea in 1939 (8). In recent years, tobacco moth lavae were observed infesting in all of the tobacco storage warehouses in this Country. Adults of the tobacco moth for the seasonal occurrence were studied in the three and four regions in 1981 and 1982, respectively. This species was caught from early May to late October in all regions for both years. In 1981, the first emergence peak was in late May to late at Andong, early June at Suweon and the second one in middle August in both regions. In 1982, on the other hand, there were three peak times, late May and July, and middle September. But the relate size of the peaks was different in two years; the second peak showed about 66% of the total number of tobacco moths captured in the whole year in 1981 at Suweon and 59% of those at Andong, while the first peak had 32% at Suweon and 57% at Shintanjin in 1982. This difference in relative peak sizes was discussed.

• Korean journal of applied entomology
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• v.46 no.1 s.145
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• pp.27-35
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• 2007

Seasonal occurrences of tobacco cutworm, Spodoptera litura and beet armyworm, Spodoptera exigua were observed using sex pheromone traps at different locations and climatic regions in Yeongnam district. In Gyeongnam province, S. litura male adults kept occur from mid or late March to mid or late November Whereas in Gyeongbuk province, S. litura occurred from mid or late April to early or mid November with exception at Uljin where it was late May to late October. According to the climatic regions, the peak occurrence of S. litura was middle September at the southern coast region, late August at the inland and the basin region, middle August at the inland mountainous region, and early September at the eastern middle coast region. The occurrence rate of S. litura was the highest at Jinju with 20.0% and the lowest at Changyeong with 8.6% in Cyeongnam province, while it was the highest at Sungju with 3.3% and the lowest at Uljin with 0.8% in Gyeongbuk province. In accordance with the climatic regions, the occurrence rate of S. litura was the highest at the inland region with 43.7%, and followed by the southern coast region (36.3%), the basin region (8.4%) and the inland mountainous region (7.0%), and was the lowest at the eastern middle coast legion with 4.6%. On the other hand, S. exigua occurred from early March to middle November with the exception of the eastern middle coast region including Pohang, Yeongdeog and U]ien in Cyeongbuk province where it occurred from mfd April to middle November. The peak occurrence of s. exigua was early August at the inland region, the basin region and the inland mountainous region, and was late of August at the southern coast region and the eastern middle coast region. The occurrence of S. exigua was the highest at Changyeong with 1.6% and the lowest at Busan with 0.4% in Gyeongnam province, while it was the highest at Sungju with 37.2% and the lowest at Uljin with 2.7% in Gyeongbuk province. The climatic regional occurrence rate of S. exigua was the highest at the basin region with 54.3%, and followed by the inland mountainous region (29.9%), the eastern middle coast region (9.3%) and the inland (3.9%), and was the lowest at the southern coast region with 2.6%. As a whole, S. litura occurred more in Gyeongnam province than Cyeongbuk province, while S. exigua occurred more in Gyeongbuk province than Gyeongnam province. According to the regions grouped by climatic differences, the occurrence of S. litura and S. exigua was the highest at the inland region in Gyeongnam province and at the basin region in Gyeongbuk province. The total number of S. litura captured by sex pheromone trap was 2.4 times higher than that of S. exigua. However, the first occurring time and the peak occurrence of S. exigua were slightly earlier than those of S. litura.

• Research in Plant Disease
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• v.11 no.1
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• pp.10-15
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• 2005

The occurrence of melanose was investigated on yuzu at Goheung and Boseong in Jeonnam province in 1997 and 1998 seasons. The disease occurrence on leaf was initiated from late May in 1997 and early May in 1998, severest in late of June on leaf, and in case of fruit, initiated from early July in 1997 and late June in 1998 with a peak in early August. The disease was occurred in twenty days more earlier in 1998 season than 1997 season. We think this was caused by temperatures during April and May. And it was supposed that the disease severity on the severest late of June was closely related to the rainfall and relative humidity during June. The disease severity was severer in old tree than the young.

• Plant Disease and Agriculture
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• v.1 no.1
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• pp.45-46
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• 1995

In recent years, there were considerably severe occurrences of TuMV(turnip mosaic virus) disease on radish and Chinese cabbage cultivated at alpine or sub-alpine regions, especially more severe on young Chinese cabbage sowed after late June. Started from 1991, those were very severe in 1992 and 1994, for the number of migrated aphids was increased enormously according to the weather condition of high temperature and low humidity then. This disease started at late June to early July, and continued to late August. It seemed that TuMV was transmitted easily and completely to the young chinese cabbages, but hardly and rarely the old. The regions over 1,000m of altitude had less possibility of disease-occurring, but there was severe occurrence on the second cropping of Chinese cabbage in a year. It is considered that more researches on control method of TuMV disease will be needed very urgently.

• Korean journal of applied entomology
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• v.29 no.2
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• pp.104-112
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• 1990

Studies were conducted to investigate hosts, life cycle, population dynamics and natural enemies of mulberry scale, Pseudaulacaspis pentagona Ta. & Tozz., from 1987 to 1988 in southern region of Korea. The host plants were 22 families and 74 species. Host plants belonged to genus Prunus in general were severely damaged due to mulberry scale. Mulberry scale was most likely to have three generations a year with first occurrence of larval stage from mid-May to late June, second occurrence from mid-July to mid-August and third occurrence from early September to late October including 3 peaks in early and mid-June, late July and mid-September. In case of each stage occurrence, eggs were peaked on 10th day, larvae on 25th day and adults on 7th day from beginning of occurrence, respectively. Natural enemies were observed as parasitoids of 3 species such as Aphytis diaspidis, Archenomus orientalis and Apterencyrtus mocrophagus and as predators of 3 species such as Chilocorus Kuwanae, Chilocorus rubidus and Hormonia axyridis. Shoot growth was affected by mulberry scale and Lepra to dwindle as much as half of normal growth.

• Korean journal of applied entomology
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• v.37 no.1
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• pp.49-52
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• 1998

This study was carried to investigate the seasonal occurrence of Step17~initisp yr-ioide.~ Scott (Hemiptera : Tingidae) in a azalea field at Wan.1~. Chonbuk, Korea in 1994. S, pyr-ioic1c.c had LIP to four generations in Chonbuk. The peaks of adult population for each generation were late May, mid-July. late-August, iuid mid-October. respectively. S. pyrioidrs overwintered as egg stage within the midribs of the host leaves.