• Title/Summary/Keyword: 포식 기생자

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Natural parasitism of parasitoids on Phyllocnistis citrella (Lepidoptera: Gracillaridae) in Jeju citrus orchards in Korea (제주 감귤원에서 귤굴나방에 대한 포식 기생자 천적의 자연 기생율)

  • Hyun, Seung Young;Lim, Un Taek;Kim, Dong-Soon
    • Korean journal of applied entomology
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    • v.58 no.4
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    • pp.299-303
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    • 2019
  • This study was conducted to investigate the species of native parasitoids attacking Phyllocnistis citrella and their parasitism in citrus orchards in Jeju, Korea. During the survey period from 2013 to 2014, seven parasitoids belonging to Chalcidoidea were found: majority of the parasitoids were Sympiesis striatipes with 73% and Quadrastichus sp. with 22% in Eulophidae. The others were Neochrysocharis sp., Pnigalio sp., Holcopelte sp., Ageniaspis sp. (Encyrtidae) and Trichomalopsis sp. (Pteromalidae). Average parasitism rate reached 10.7% in orchards with spraying insecticide, and 32.2% in environmental-friendly managed orchards.

Studies on the Natural Enemies of Protopulvinaria mangiferae(Green) (Homoptera : Coccidae) (담팔수깍지벌레의 천적에 관한 연구)

  • Kim, Jong-Kuk;Morimoto, Katsura
    • Journal of Forest and Environmental Science
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    • v.14 no.1
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    • pp.128-137
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    • 1998
  • In Fukuoka, the natural enemies of Protopulvinaria mangiferae were confirmed as six primary parasitoids, three hyperparasitoids, and six predators. Among the primary parasitoids, Aneristus ceroplastae, Microterys flavus, and Coccophagus yoshidae were relatively abundant in Fukuoka. Aneristus ceroplastae and Coccophagus yoshidae were solitary endoparasitoid, whereas Microterys flavus was a gregarious endoparasitoid. Tetrastichus sp. was a hyperparasitoid and solitarily ectoparasitic to the pupae of Aneristus ceroplastae and Microterys flavus. The seasonal fluctuation of parasitisim and adult emergence of the important parasitoids was investigated in Fukuoka. Among the predatorys, Rhyzobius forestieri and Chilocorus kuwanae were relatively abundant, and seasonal fluctuation of adult emergence and consumption of the host were studied. As the first record from Japan, Rhyzobius forestieri was collected on leaves of Elaeocarpus sylvestris with heavy infestation of Protopulvinaria mangiferae.

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해양미생물의 세계 - 박테리아의 삶과 죽음

  • Jo, Byeong-Cheol
    • The Science & Technology
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    • v.35 no.3 s.394
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    • pp.19-19
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    • 2002
  • 바닷물 속의 미생물세계는 매우 역동적이며 먹고 먹히는 긴박한 육상의 정글과 같다. 해양 박테리아를 위협하는 포식자와 기생자 그리고 먹고 먹히는 박테리아의 생존세계를 본다.

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Management of the Development of Insecticide Resistance by Sensible Use of Insecticide, Operational Methods (실행방식 측면에서 살충제의 신중한 사용에 의한 저항성 발달의 관리)

  • Chung, Bu-Keun;Park, Chung-Gyoo
    • Korean journal of applied entomology
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    • v.48 no.2
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    • pp.123-158
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    • 2009
  • An attempt was made to stimulate future research by providing exemplary information, which would integrate published knowledge to solve specific pest problem caused by resistance. This review was directed to find a way for delaying resistance development with consideration of chemical(s) nature, of mixture, rotation, or mosaics, and of insecticide(s) compatible with the biological agents in integrated pest management (IPM). The application frequency, related to the resistance development, was influenced by insecticide activity from potentiation, residual period, and the vulnerability to resistance development of chemical, with secondary pest. Chemical affected feeding, locomotion, flight, mating, and predator avoidance. Insecticides with negative cross-resistance by the difference of target sites and mode of action would be adapted to mixture, rotation and mosaic. Mixtures for delaying resistance depend on each component killing very high percentage of the insects, considering allele dominance, cross-resistance, and immigration and fitness disadvantage. Potential disadvantages associated with mixtures include disruption of biological control, resistance in secondary pests, selecting very resistant population, and extending cross-resistance range. The rotation would use insecticides in high and low doses, or with different metabolic mechanisms. Mosaic apply insecticides to the different sectors of a grid for highly mobile insects, spray unrelated insecticides to sedentary aphids in different areas, or mix plots of insecticide-treated and untreated rows. On the evolution of pest resistance, selectivity and resistance of parasitoids and predator decreased the number of generations in which pesticide treatment is required and they could be complementary to refuges from pesticides To enhance the viability of parasitoids, the terms on the insecticides selectivity and factors affecting to the selectivity in field were examined. For establishment of resistant parasitoid, migration, survivorship, refuge, alternative pesticides were considered. To use parasitoids under the pressure of pesticides, resistant or tolerant parasitoids were tested, collected, and/or selected. A parasitoid parasitized more successfully in the susceptible host than the resistant. Factors affecting to selective toxicity of predator are mixing mineral oil, application method, insecticide contaminated prey, trait of individual insecticide, sub-lethal doses, and the developmental stage of predators. To improve the predator/prey ratio in field, application time, method, and formulation of pesticide, reducing dose rate, using mulches and weeds, multicropping and managing of surroundings are suggested. Plant resistance, predator activity, selective insect growth regulator, and alternative prey positively contributed to the increase of the ratio. Using selective insecticides or insecticide resistant predator controlled its phytophagous prey mites, kept them below an economic level, increased yield, and reduced the spray number and fruits damaged.

A History of Investigations of Population Dynamics and Epidemiology (집단 및 질병 동역학에 대한 역사발생적 고찰)

  • Lee, Weon Jae;Han, Gil Jun
    • Journal for History of Mathematics
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    • v.26 no.2_3
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    • pp.197-210
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    • 2013
  • The late 18C Malthus studied population growth for the first time, Verhulst the logistic model in 19C and, after that, the study of the predation competition between two species resulted in the appearance of Lotka-Volterra model and modified model supported by Gause's experiment with bacteria. Instable coexistence equilibrium being found, Solomon and Holling proposed functional and numerical response considering limited abilities of predator on prey, which applied to Lotka Volterra model. Nicholson and Baily, considering the predation between host and parasitoid in discrete time, made a model. In 20C there were developed various models of disease dynamics with the help of mathematics and real data and named SIS, SIR or SEIR on the basis of dynamical phenomena.

First Records of Genera Cycetogamasus and Neogamasus of Parasitidae (Parasitiformes: Mesostigmata) from the Republic of Korea (한국산 온판기생응애속과 두판기생응애속(중기문응애: 기생응애과) 미기록종 보고)

  • Keum, Eunsun;Kaczmarek, Slawomir;Marquardt, Tomasz;Jung, Chuleui
    • Korean journal of applied entomology
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    • v.58 no.1
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    • pp.15-25
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    • 2019
  • Mites in the family Parasitidae (Mesostigmata) are important predators in soil ecosystem. During the soil acarine biodiversity study from diverse habitats in the Republic of Korea, we found newly recording species of parasitid mites of genus Cycetogamasus and Neogamasus. This paper reports two species Cycetogamasus coreanus and C. corculatus of genus Cycetogamasus and five species Neogamasus eogenualis, N. tikhomirovi, N. laciniatus, Neogamasus kengicus and Neogamasus mahunkai of genus Neogamasus as new record in the Republic of Korea.

Influence of (E)-2-hexenyl (Z)-3hexenoate on the Occurrence of Egg Parasitoids, Ooencyrtus nezarae (Hymenoptera: Encyrtidae) and Gryon japonicum (Hymenoptera: Scelionidae), in Apple Orchards (사과원에서 (E)-2-hexenyl (Z)-3hexenoate 성분이 노린재깡충좀벌(Ooencyrtus nezarae)(Hymenoptera: Encyrtidae)과 노린재기생알벌(Gryon japonicum) (Hymenoptera: Scelionidae) 발생에 미치는 영향)

  • Baek, Seonghoon;Park, Chung Gyoo;Seo, Bo Yoon;Cho, Jum Rae;Park, Chang-Gyu
    • Korean journal of applied entomology
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    • v.60 no.1
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    • pp.91-98
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    • 2021
  • The populations of Riptortus pedestris (Fabricius) cause serious economic damages in local apple orchards. However, there was no study to manage its populations with environment friendly tactics. Thus, this study was conducted to analyze its attraction effects of one of R. pedestris aggregation pheromone compounds, (E)-2-hexenyl (Z)-3hexenoate (E2HZ3H), to its parasitoids, Ooencyrtus nezarae (Ishii) and Gryon japonicum (Ashmead). This compound did not increase the number of these two parasitoids and change its spatial distribution. However, this compound could attract two parasitoids within limited distance. These results indicates that one compound of R. pedestris aggregation pheromone, E2HZ3H, could be a good candidate to manage R. pedestris populations in conditions that its populations locally occurs in apple orchards.

Response of Terrestrial Insect Community to the Vegetation Invasion at a Sand-Bed Stream (모래하천에서 식생 침입에 대한 육상곤충 군집의 반응)

  • Cho, Geonho;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.4 no.1
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    • pp.44-53
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    • 2017
  • In order to investigate the response in fauna and biological communities of terrestrial insects to the vegetation encroachment on the sandbar, species composition, species diversity, functional species traits and community structure of land-dwelling insects sampled by a pit-fall trap were compared at the bare and vegetated sandbar of a typical sand-bed stream, the Naeseong Stream, Korea. Species diversity of the insects was increased but their density was decreased as the riparian vegetation encroached at the sandbar. In particular, indicator species of bare sandbar such as Cicindela laetescripta and Dianemobius csikii, were found at the bar sandbar. The insect communities were clearly classified at the bare and vegetated sandbar according to coverages of riparian plants. The food web of the bare sandbar was composed of detritus - detritivore and scavenger - predator consisted mainly of Coleoptera. On the other hand, the food web of the vegetated sandbar was composed of plants - sucking and chewing herbivore - parasitoid and predator. These results showed that biodiversity of terrestrial insects was increased, food web was changed from grazing to detritus food chain, and insect fauna specific bare sandbar disappeared as the riparian vegetation invaded on the sandbar of a sand-bed stream.

Physiological Ecology of parasitic Dinoflagellate Amoebophrya and Harmful Algal Blooms (기생성 와편모류 Amoebophrya의 생리 생태적 특성과 적조)

  • 박명길
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.7 no.3
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    • pp.181-194
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    • 2002
  • Parasitism is a one-sided relationship between two organisms in which one benefits at the expense of the other. Parasitic dinoflagellates, particularly species of Amoebophrya, have long been thought to be a potential biological agent for controlling harmful algal bloom(HAB). Amoebophrya infections have been reported for over 40 species representing more than 24 dinoflagellate genera including a few toxic species. Parasitic dinoflagellates Amoebophrya spp. have a relatively simple life cycle consisting of an infective dispersal stage (dinospore), an intracellular growth stage(trophont), and an extracellular reproductive stage(vermiform). Biology of dinospores such as infectivity, survival, and ability to successfully infect host cells differs among dinoflagellate host-parasite systems. There are growing reports that Amoebophrya spp.(previously, collectively known as Amoebophrya ceratii) exhibit the strong host specificity and would be a species complex composed of several host-specific taxa, based on the marked differences in host-parasite biology, cross infection, and molecular genetic data. Dinoflagellates become reproductively incompetent and are eventually killed by the parasite once infected. During the infection cycle of the parasite, the infected host exhibits ecophysiologically different patterns from those of uninfected host in various ways. Photosynthetic performance in autotrophic dinoflagellates can be significantly altered following infection by parasitic dinoflagellate Amoebophrya, with the magnitude of the effects over the infection cycle of the parasite depending on the site of infection. Parasitism by the parasitic dinoflagellate Amoebophrya could have significant impacts on host behavior such as diel vertical migration. Parasitic dinoflagellates may not only stimulate rapid cycling of dissolved organic materials and/or trace metals but also would repackage the relatively large sized host biomass into a number of smaller dinospores, thereby leading to better retention of host's material and energy within the microbial loop. To better understand the roles of parasites in plankton ecology and harmful algal dynamics, further research on a variety of dinoflagellate host-parasite systems is needed.

Status of the Occurrence of Insect Pests and Their Natural Enemies in Soybean Fields in Honam Province (호남지역 콩 재배지 주요해충 및 천적류)

  • Paik, Chae-Hoon;Lee, Geon-Hwi;Choi, Man-Young;Seo, Hong-Yul;Kim, Doo-Ho;Hwang, Chang-Yeon;Kim, Sang-Soo
    • Korean journal of applied entomology
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    • v.46 no.2
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    • pp.275-280
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    • 2007
  • This survey was conducted to illustrate insect pests and their natural enemies in soybean fields in Honam area. A total of 23 pest species in 13 families and 13 species of natural enemy were observed during 2002 to 2003. Delia platura, Medythia nigrobilineata, Spodoptera exigua and Aphis glycines occurred relatively with high population densities during the early growth stage of soybean. Dolycoris baccarum, Riptortus clavatus, Nezara antennata, Piezodorus hybneri and Halyomorpha halys began to occur between mid July to early August and lasted until the harvest time. Lepidopteran insect pests, Leguminivora glycinivorella, Pleuroptya ruralis, Scopula missaria, Macdunnoughia purissima and Spodoptera litura occurred significantly in late August in soybean field. Natural enemies of soybean insect pests observed in this survey were seven parasitoids, five predators, and an entomopahogenic fungus. Two egg parasitoid species for R. clavatus, two parasitoid species for P. ruralis, and five natural enemy species (including parasite, predator and entomopathogenic fungi) for either S. litura or A. glycines were identified, respectively. Among them two egg parasitoid species, Gryon japonicum and Ooenyrtus nezarae for R. clavatus, for and one parasitoid species for P. ruralis, that belong to Bethylidae, were new to Korea.