• Korean journal of applied entomology
• /
• v.27 no.2
• /
• pp.117-124
• /
• 1988

An Investigation of insect pests in rice stored was carried out in Jeonnam region of Korea. The total of 2 class, 7 orders 16 families and 25 species were recorded in Lepidoptera; 8, Coleoptera; 11, Orthoptera; 1, Thysanura 1, blattaria; 2, Hymenoptera; 1 and mites; 2 spe-cies. The important species among them were Sitotroga cerealella, Ephestia cautella, Paral-ipsa gularis, Poldia, in Lepidoptera, and Sitophilus orzae, Oryzaephilus surianmensis, Cryptolestes ferrugineus, Tribolium castaneum, Tenebroides mauritanicus, Attagenus japonicus, in Coleoptera and Blatella germanica, in Blattaria and Acarus siro Petrobia latens, in mites. The duration of maximum occurrence were the late June to mid July for Sitotroga cerealella, the mod July to early August for Oryzaephilus surianmensis the mid July to August for Tribolium castaneum, the early July to late July for Sitophilus orzae, the mid June to early July for Attagenus japonicus the mid June to late Spetember for Blatella germanica and the late April to late May for Acarus siro and Petrobia latens, respectively in investigation, Blatella germanica(Blattaria) which was no problem in stored rice insect till now was mainly distributed a coastal plain and period of occurrence was long amount of occurrence was great. Rice weevil has 4 generations under natural conditions and the peak of 1st perood time was ranged from middle of jun. to last decade of Jun., 2nd period was from the lats decade of Jul. to first decade of Aug., 3rd period was from middle of Sep. to late Sep., 4th period was middle of Oct. to early Nov.

• Korean journal of applied entomology
• /
• v.29 no.4
• /
• pp.269-276
• /
• 1990

This study investigated host range, seasonal occurrence and developmental characteristics of Ceroplastes pseudoceriferus Green on persimmon trees. The host plants covered 34 families and 66 species, including newly recorded species of Chenopodum album var. centrorubrum, Glycine max, Begonia semperflorens, Pharbitis nil, Perilla frutescens var. japonica and Erigeron canadensis. There was one generation of C. pseudoceriferus a year with larval stage expanding from mid-June to mid-October. Average number of eggs laid per female was 1,073$\pm$177.3. Hatching rate was 97.3% and was not affected by temperatures and photoperiods. Stadium varied as 23.4 days in eggs, 128.3 days in larvae and 213.3 days in female adults including overwintering periods at natural condition.

• Korean journal of applied entomology
• /
• v.23 no.4 s.61
• /
• pp.237-241
• /
• 1984

The trichogrammatidae ego parasite of the green rice leafhopper (GRLH), paracentrobia andoi, were investigated to know their parasitic activities after overwintering in the paddy banks and fallow fields, their seasonal variation and per cent parasitism in the paddy fields of Gyeongnam provincial O.R.D. at Jinju from 1982 to 1984. The parasitic activities of Paracentrobia andoi after overwintering in the Paddy banks in early Masch were high and tended to decrease remarkably since early April by moving to the fallow fields. The parasitic rate of paracentrobia andoi on GRLH was $21\%$ between late April and early May. the peak of egg laying period of GRLH. The per cent parasitism of the wasps in fallow fields was an average of $0\%$ in Gyeochang and Namji and $9.6-29.2\%$ in Namhae, Kimhae and Jinju. The parasitic activites of Paracentrobia andoi had three peakrs in paddy field, however, the highest peak was ovserved between mid- August and early October. The per cent egg parasitism of Paracentrobia andoi was an average of $16.5\%$ on second generation of Nepotettix cinctireps and $36.7\%$ on third generation of the leafhopper.

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

• Proceedings of the KIPE Conference
• /
• 2004.07a
• /
• pp.430-434
• /
• 2004

본 논문에서는 관전류 직접제어 방식을 채택한 3.2kW(80kV,40mA)급 최소형, 최경량 Portable X-선 장치를 제안한다 본 장치는 X-선 발생을 위한 고전압 발생 단에 모노탱크 블록 사용하였고, 고주파 고전압용 인버터에는 스위칭 전력소자로서 Mini block type의 MOS-FET를 채용, 80kHz로 스위칭 함으로서 고전압 변압기를 비롯한 고전압 발생부의 크기와 무게를 최소화하였다. X-ray Power의 출력이 높아짐에 따라, X-ray tube의 필라멘트 인버터의 출력용량 또한 증가되었다. 본 논문에서는 설정 관전류에 대한 정밀한 제어를 위하여 2단계 모드로 필라멘트 예열을 행하여 관전류 응답특성을 개선하였으며 제안한 휴대용 X-선 발생장치의 부하변동에 따른 X-선 관전압과 관전류의 개선된 특징을 실험파형을 통하여 입증하였다.

• Proceedings of the KIPE Conference
• /
• 2003.07b
• /
• pp.750-754
• /
• 2003

본 논문에서는 X-선 관전류를 직접 검출하여 제어하는 2.4kW(80kv,30mA)급 최소형, 최경량 휴대용 X-선 발생 장치를 제안한다. 본 장치는 X-선발생을 위한 고전압 발생단에 모노탱크 블록 사용하였고, 고주파 고전압용 인버터에는 스위칭 전력소자로서 MOS-FET를 채용, 70kHz로 스위칭 함으로서 고전압 변압기를 비롯한 고전압 발생부의 크기와 무게를 최소화하였다. 또한, 설정 관전류에 대한 정밀한 제어를 위하여 2단계 모드로 필라멘트 예열을 행하여 관전류 응답특성을 개선하였으며 제안한 휴대용 X-선 발생장치의 부하변동에 따른 X-선 관전압과 관전류의 개선된 특징을 실험파형을 통하여 입증하였다.

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

• Korean journal of applied entomology
• /
• v.43 no.4 s.137
• /
• pp.291-296
• /
• 2004

Overwintering sites and Seasonal occurrence of various growth stage of the rice black bug, Scotinophara lurida BURMEISTER were studied at the rice paddy field in Chungbuk area, from 1999 to 2001. Attraction by light trap from overwintering site of overwintering adults occurred from early June to mid July and its peak was shown on late June. Eggs were oviposited from early July to early August and its peak appeared in late July. Nymphs were observed from mid July to late September with its peak on mid August. The newly eclosed rice black bugs were found in late August and its peak on mid September. The rice black bug overwintered as adult at mountain foot, banks, and rice paddy levee.

• Korean journal of applied entomology
• /
• v.41 no.3
• /
• pp.199-204
• /
• 2002

Population fluctuation of O. kashmirica benefica, a major natural enemy of citrus red mite (Panonychus citri), was surveyed from 1997 to 2000 in yuzu orchards in Goheung region and, developmental periods, developmental threshold temperature (DT) and effective cumulative temperature (ET) were estimated. Under four constant temperatures of 15, 20, 25 and 30$\^{C}$, developmental periods from egg to adult of the beetles were 67.3, 31.4, 19.4 and 15.3 days, respectively. The period of each stage was long in the order of pupa> egg > 3rd larva> 2nd larva> 1st larva. Mean numbers of eggs oviposited by a female per day were 3.3, 5.6, 7.3 and 7.7 under the temperatures, respectively. The highest hatchability (92%) and adult emergence (60%) were shown under 25$\^{C}$. Adult longevity was 54.3 days for females, and 58.6 days for males. In natural condition, the sex ratio of the beetle was 0.58. Developmental thresholds (DT) for egg, 1st, 2nd, 3rd larva, pupa, and egg to adult were 12.7, 10.0, 10.8, 7.9, 10.1 and 10.6$\^{C}$, respectively. The effective cumulative temperatures (ET) were 41.4, 22.9, 22.7, 46.6, 165.3, 292.9 day-degree at the same development stage, respectively. The beetle occurred from early April to early December in yuzu orchards. The population peak of the beetles was dependent on the amount of prey mite (Panonychus citri), and the ratio of the predator to prey mite was 1 to 100-200 at predator peak stage in the field.

• Korean journal of applied entomology
• /
• v.45 no.1 s.142
• /
• pp.9-13
• /
• 2006

Seasonal occurrence of thrips and its damage on fruits were studied at in open field red pepper in Jeonbuk Province. The kind of thrips were Franklinella occidentalis and F. intonsa. The ratio of F. occidentalis was about 30% in periods of survey. Density of thrips increased in late May and showed peak occurrence in early to middle July. The peak occurrence of thrips was appeared at 4 pentad June, 2 pentad July, 3 pentad August, and 4 pentad September. The part of fruit damaged by thrips became discolored and roughed. When turned red, the colors of damaged parts changed from dark brown to yellowish brown. As a result, damage fruits by thrips decreased marketability. The percent of damaged fruits was highest in Imsil at 20.8% in early August. Density of thrips on flowers was highest in middle July.