• Title/Summary/Keyword: 기생율

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Studies on parasitic trematodes in bivalves -Variation of infection rate of Cercaria tapidis and Cercaria harengulae- (조개류에 기생하는 흡충류에 관한 연구 - Cercaria tapidis, Cercaria harengulae 의 기생율 변동)

  • Kim, Young-Gill;Lee, Keun-Kwang;Kim, Young-Jin
    • Journal of fish pathology
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    • v.8 no.1
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    • pp.23-30
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    • 1995
  • We had reported the infection rates of trematode larvae, Cercaria tapidis and C. harengulae in the gonad tissues of Tapes philippinarum and Solen strictus in the estuary of Kum river, the west coast in Korea in 1980~1982. At the same sites from January 1994 to January 1995, we investigated the variation of the infection rates of these trematode larvae in the two clams. The results are follows. The infection rate of C. tapidis parasitized in T. philippinarum increased in 2.4 times (14.0%) higher than that (5.7%) in 1981. Monthly maxium infection rate was 32.0% in October 1994. Comparing the rate (23.3%) in December 1981, the rate in 1994 showed a higher trend than that in 1981. The mean infection rate of C. harengulae in T. philippinarum showed 2.3% in 1994. Comparing that (5%) in 1980, it showed a decreased rate than that in 1980. And monthly maximum infection infection rate of this clam was 6.7% in May 1994, compared with the rate (19.0%) in March 1980. It appeared furthermore decreased rate in 1994. The mean infection rate of the year of C. harengulae in S. strictus was 6.9% in 1994, while it was 10.2% between 1981 and 1982. It showed a decreased trend in 1994. Monthly maximum infection rate was 23.4% in August 1981, while it was 13.3% in April 1994. It showed a decreased trend in 1994 also. In case of C. tapidis the more large sizes of shell length the more infection rates were higher as same in the investigation in 1980, while in C. harengulae the smaller sizes, the more infection rates showed a higher trend.

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Trematodes larva in 3 species of bivalves )Corbicula japonica, Sinonovaculla constrica and Ruditaps philippnarum) (간석지산 이매패에서의 흡충류 유충에 관한 연구)

  • Kim, Yeong-Gil;Yun, Gwon-Sik
    • Journal of fish pathology
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    • v.16 no.3
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    • pp.203-213
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    • 2003
  • The present study was conducted to research some parastic trematodes species in marine bivalves which are widely distributed in the western sea in Korea. From April, 2001 to October, 2002, marsh calm (Corbicula japonica) were obtained from Kochang bay near the Sunun temple and razor calm (Sinonovaculla constricta) from Kaehwado. Short necked calm (Ruditapes philippnarum) were sampled from Ochungdo, Mardo and Kaeyado. Cercaria corbiculae was found in the gonad of C. japonica with a low infection rate of 0.83%. The cercaria and the sporocyst were sized $278{\times}98{\mu}$ and $890{\times}275{\mu}$, respectively. Some encysted larvae of Parvatrema duboisi sized $0.351{\times}0.182mm$ were firstly found in the mantle of S. constricta in Korea. Each S. constricta contained 1-9 cysts and the infection rate was 48.3%. Cercaria tapidis was found in the both gonad and mantle of R. philippinarum. The annual average infection rate in the R. philippinarum from Ochungdo was 7.7%. This rate was much higher than those from Solri near the Kum river estuary in 1981. The infection rate of C. tapidis in R. philippinarum was different in sizes. The maximum rate was 4.8% in size 3.6-4.0cm and the minimum rate 0.8% in size 4-5cm.

Wing Morphs and Parasitism Rates of the Small Brown Planthopper, Laodelphax striatellus (Hemiptera: Delphacidae) in Korea (국내 애멸구 (Laodelphax striatellus Fallen) (노린재목: 멸구과)의 시기별 날개형 및 기생율)

  • Son, Byung-In;Jung, Jong-Kook;Lee, Joon-Ho
    • Korean journal of applied entomology
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    • v.53 no.4
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    • pp.497-501
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    • 2014
  • The small brown planthopper, Laodelphax striatellus (Fall$\acute{e}$n) (SBPH) is one of the important rice pests in Korea, which transmits rice stripe virus (RSV) to rice. This pest is an indigenous species in Korea and has also known to migrate from China to the western coastal areas of Korea. This study was conducted to investigate the wing morphs of SBPH and its parasitism rate of Haplogonatopus atratus Esaki et Hashimoto in Korea. In 2014, SBPH were collected in April and July from 16 sites throughout South Korea and their wing morphs and parasitism rates were measured under the microscope. Percentage of brachypterous male in July was significantly declined compared to that in April, while that of brachypterous female did not change. A positive relationship was found between latitude and percentage of brachypterous adults in April. Parasitism rate of both nymphs and adults were higher in April than July. In addition, nymphal parasitism rate was generally higher in western coastal areas.

Parasitism Rate of Egg Parasitoid Anastatus orientalis (Hymenoptera: Eupelmidae) on Lycorma delicatula (Hemiptera: Fulgoridae) in China (중국에서 알기생봉 Anastatus orientalis (Hymenoptera: Eupelmidae)의 꽃매미 Lycorma delicatula (Hemiptera: Fulgoridae) 알에 대한 기생율)

  • Choi, Man-Young;Yang, Zhong-Qi;Wang, Xiao-Yi;Tang, Yan-Long;Hou, Zhen-Rong;Kim, Jeong Hwan;Byeon, Young Woong
    • Korean journal of applied entomology
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    • v.53 no.2
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    • pp.135-139
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    • 2014
  • Anastatus orientalis Yang et Gibson(Hymenoptera : Eupelmidae) is the egg parasitoid of lantern-fly Lycorma delicatula. The natural parasitism showed that: (1)the highest parasitism rate of egg masses was 68.96% in Yantai Shandong; (2)the highest parasitism rate of eggs was 32.98% in Haidian Beijing; (3)the eggs of parasitoids hatched and emerged earliest in Yangling Shaanxi; emergence time of different populations in Yantai, Guangang Tianjin, Qinhuangdao Hebei and Haidian was similar; (4) the sex ratios were various among the populations ranging from 1.92 to 1.94; (5) parasitism rates of egg masses on Populus sp., Salix sp. and Toona sinensis were not significantly different, the highest parasitism rate of egg masses was 64.3% on T. sinensis, and the lowest rate was 27.4% on Ailanthus altissima; (6)parasitism rates of eggs on Populus sp., Salix sp., T. sinensis and A. altissima were not significantly different, about 30% averagely.

Egg Parasitism of Green Rice Leafhopper, Nephotettix cincticeps Uhler by Gonatocerus sp. and Paracentrobia andoi in Southern Rice Cultural Areas (남부지방에 있어서 끝동매미충 난기생봉의 종류 및 기생율에 관한 조사연구)

  • Chang Y.D.
    • Korean journal of applied entomology
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    • v.19 no.2
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    • pp.109-112
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    • 1980
  • This study was carried out to investigate the distribution of egg parasitoids from green rice leafhopper, Nephotettix cincticeps Uhler, from the middle of August through the early September in southern rice cultural areas. The results were obtained as follow. 1. Four species of egg parasitoids, Gonatocerus sp. A and B, Paracentrobia andoi and Anagrus sp. are newly recorded from the eggs of green rice leafhopper. 2. Egg parasitism rates of Gonatocerus sp. were varied from $41.0\~73.9\%$ on an egg mass basis and from $29.7\~49.0\%$ on basis of egg. Percent parasitism rates by Paracentrobia andoi were $0\~9.7\%$ on an egg mass basis and from $2.1\~12.6\%$ on basis of egg. Gonatocerus sp. was dominant egg parasitoid in the parasitism rate than Paracentrobia andoi.

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Parasitylenchus orthotomici sp. n. (Tylenchida: Allantonematidae) from Orthotomicus angulatus (Coleoptera: Scolytidae), with Note on Parasitism (소나무뿔나무좀(Orthotomicus angulatus) (딱정벌레목 : 나무좀과)에서 발견된 천적선충 신종과 기생율)

  • ;Harry K. Kaya;Patrick Shea
    • Korean journal of applied entomology
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    • v.28 no.1
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    • pp.1-3
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    • 1989
  • Parasitylenchus orthotomici sp. n. is described as a nematode parasite of Orthotomicus an¬gulatus in Korea. In a sample of 170 beetles randomly collected from Pinus densiflora S. et. Z, 51. 8% were parasitized by nematodes. The number of nematodes per bark beetle was ranged from 1 to 97. The parasitisms of F, generation were ranged from 43.2% to 52%. There was no positive tendency in nematode parasitism between sun-side and shade-side.

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Parasitism of Liriomyza trifolii (Diptera: Agromyzidae) by Hemiptarsenus zilahisebessi(Hymenoptera: Eulophidae) on Tomato (토마토에서 Hemiptarsenus zilahisebessi에 의한 아메리카잎굴파리 기생율)

  • 문형철;최정식;황창연
    • Korean journal of applied entomology
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    • v.41 no.1
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    • pp.61-65
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    • 2002
  • This study was conducted to investigate percentage of parasitism and control effect of Liriomyza trifolii by Hemiptarsenus zilahisebessi on tomato. Percentages of parasitism on L. trifolii larva by ectopatasitoids war e 26∼45% Among them the parasitism by H. zilahisebessi was highest as 47∼75% in tomato. The parasitoids preferred 1 st to 3rd instar of host larvae. In laboratory test, the parasitoids showed high parasitism on 3rd instar larvae of host by 89.8∼93.1% when the female parasitoids were introduced by the ratios of 1 : 10, 1 : 20, and 1 : 30. In field test, 3 or 5 female parasitoids were introduced per plant. In the case, the parasitism increased to 80% 4 weeks after introduction of the parasitoids. This increased parasitism was resulted from density reduction of the host larvae There were no significant differences in parasitism, density of alive host, and percentage of damaged leaf between inoculation density.

Studies an the Egg Parasite, Paracentrobia andoi Ishii (Hymenoptera : Trichogrammatidae) of Green Rice Leafhopper, Nephotettix cinticeps Uhler (1) (끝동매미충 난기생봉 (Paracentrobia andoi)에 관한 연구(I))

  • Kim Jeong-bu
    • Korean journal of applied entomology
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    • v.23 no.4
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    • pp.237-241
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    • 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.

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Studies on Reproductive Ecology and Parasite of the Venus Clam, Cyclina sinensis, on the West Coast of Korea. 2. On the Metacercaria of Himasthla kusasigi Yamaguti, 1939 (Trematoda) found in the Venus Clam, Cyclina sinensis (한국 서해산 가무락조개, Cyclina sinensis의 번식생태 및 기생충에 관한 연구 2. 가무락조개에서 검출된 흡충류, Himasthla kusasigi Yamaguti, 1939에 대하여)

  • 김영길;정의영;김용호
    • The Korean Journal of Malacology
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    • v.16 no.1_2
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    • pp.43-48
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    • 2000
  • We investigated the effects of death and gametogenesis by infection of the trematode in the venus clam, Cyclina sinensis. The specimens of C. sinensis were collected monthly at the tidal flat of Kaehwado, Puan-gun and Sangpo aquafarms, Kochang-gun, Chollabuk-do, Korea, from June 1999 to May 2000. One species of a trematode, the metacercaria of Himasthla kusasigi Yamaguti, 1939 (Enchinistomatidae), was found in the venus clam, C. sinensis. Infection rates in Kaehwado area and Sangpo aquafarm were average 93% and 81%, respectively. Infection rates during the study period reached the maximum (100%) in September 1999 and March-April 2000 and showed the minimum (80%) in July in Kaehwado, while those in Sangpo aquafarm showed the maximum (99%) in January 2000 and the minimum (47%) in November 1999. The infection parts of the metacercaria of H. kusasigi in the venus clam were the visceral mass, gill, mantle including the foot. Their infection rates in Kaehwado area and Sangpo aquafarm were 76.7% and 81.3% in the visceral mass, 19.1% and 14.5% in the gill, and 5,1% and 4.2% in the mantle, respectively. Infection rates of H. kusasigi showed higher with the increase of the size of the clams. No abnormal characteristics in the various tissues by histological observations were found in the clams infected by the metacercaria of H. kusasigi because this clam is the second intermediate host.

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