• 한국응용곤충학회지
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• 제36권3호
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• pp.237-242
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• 1997

폿트 재배한 강낭콩에서 점박이응애(Tetranychus urticae Koch)를 먹이로 제공하여 야외와 온실에서 3종 이리응애에 의한 점박이응애에 밀도 조절 작용에 대해 조사한 결과 다음과 같다. 6-7일 야외에서 A. fallacis는 점박이응애와 이리응애의 접종밀도 비율이 4:1, 10:1, 20:1 수준에서 접종 17일 후에 점박이응애의 밀도억제가 가능하였으나, A. womersleyi는 4:1에서만 밀도억제가 가능하였고, T. occidentallis는 4:1에서 접정 30일 후와 10:1, 20:1의 비율에서는 점박이응애 밀도억제가 전혀 불가능하f였다. 9월에 온실에서 점박이응애와 이리응애의 밀도를 10:1로 접종하였을 때 A. womersleyi는 초기 점박이응애 밀도억제가 가능하였으나 13일 이후에는 불가능하였고, A. womersleyi는 접종밀도보다 감소하였다. A. womersleyi는 초기부터 안정된 밀도가 유지되어 점박이응애 밀도억제 효과가 지속적이었다. T. occidentallis는 후기에 밀도가 증가하여 점박이응애 후기 밀도억제가 가능하였다.

• 한국응용곤충학회지
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• 제39권4호
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• pp.251-258
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• 2000

진딧물류의 포식성 천적인 칠성풀잠자리붙이의 충태, 온도조건, 먹이밀도 조건 등에 따른 포식량 및 몇 가지 채소작물에서 진딧물 밀도억제 효과를 조사한 결과, 칠성풀잠자리붙이 3령유충은 17, 22, 및 $27^{\circ}C$에서 각각 29.8, 77.9, 133.6 및 155.7마리의 목화진딧물을 포식하였으며,$ 27^{\circ}C$에서 산란전 성충은 73.1마리, 산란중인 성충은 86.6마리, 수컷성충은 69.7마리의 복숭아혹진딧물을 포식하였다. 칠성풀잠자리붙이는 목화진딧물 밀도가 증가하면 포식량도 점차 증가하였으나 그 증가율은 차차 감소하는 Holling의 기능적 반응곡선 제II형(포화형)과 일치하는 경향이었으며, 칠성풀잠자리붙이 3령 유충은 탐색률이 가장 높고 탐색시간은 짧았다. 칠성풀잠자리붙이의 목화진딧물 제어능력은 고추, 가지, 토마토에서 칠성풀잠자리붙이 난:진딧물의 비율이 1:4, 오이는 1:3일 때 효과적이었다. 또한 칠성풀잠자리붙이 2령 유충:진딧물의 비율이 고추에서 1:30,오이와 토마토에서는 1:20일 때 효과적으로 진딧물 밀도를 억제할 수 있었다. 시설하우스에 고추를 정식한 후 6월~9월 사이에 약제방제 4회 실시한 것과 칠성풀잠자리붙이 난을 3회 접종한 것의 방제효과가 비슷하였다.

• ALGAE
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• 제38권1호
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• pp.57-70
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• 2023

The mortality rate of red-tide dinoflagellates owing to predation is a major parameter that affects their population dynamics. The dinoflagellates Ansanella granifera and Ansanella sp. occasionally cause red tides. To understand the interactions between common heterotrophic protists and A. granifera, we explored the feeding occurrence of nine heterotrophic protists on A. granifera and the growth and ingestion rates of the heterotrophic dinoflagellate Gyrodinium dominans on A. granifera as a function of prey concentration and those of Oxyrrhis marina at a single high prey concentration. The heterotrophic dinoflagellates Aduncodinium glandula, G. dominans, Gyrodinium moestrupii, Luciella masanensis, Oblea rotunda, O. marina, Polykrikos kofoidii, and Pfiesteria piscicida and the naked ciliate Strombidium sp. were able to feed on A. granifera. With increasing mean prey concentrations, the growth and ingestion rates of G. dominans feeding on A. granifera rapidly increased and became saturated or slowly increased. The maximum growth and ingestion rates of G. dominans on A. granifera were 0.305 d^-1 and 0.42 ng C predator^-1 d^-1 (3.8 cells predator^-1 d^-1), respectively. Furthermore, the growth and ingestion rates of O. marina on A. granifera at 1,700 ng C mL^-1 (15,454 cells mL^-1) were 0.037 d^-1 and 0.19 ng C predator^-1 d^-1 (1.7 cells predator^-1 d^-1), respectively. The growth and ingestion rates of G. dominans and O. marina feeding on A. granifera were almost the lowest among those on the dinoflagellate prey species. Therefore, G. dominans and O. marina may prefer A. granifera less than other dinoflagellate prey species. The low mortality rate of A. granifera may positively affect its bloom formation.

• Journal of Microbiology and Biotechnology
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• 제14권1호
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• pp.48-55
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• 2004

Six strains of an obligate predatory bdellovibrio isolate that preys on Burkholderia glumae in rice paddy field water and rhizosphere soil, were identified and characterized. The numbers of Bdellovibrio cells varied from $3.2{\times}10^3$ to $9.2{\times}10^3$ plaque-forming unit/g after enrichment in cells of B. glumae. Prey range tests with six Bdellovibrio strains and 17 prey strains of rice-pathogenic, antibiosis-related, or nitrogen-fixing bacteria resulted in unique predation patterns in related prey cells. Strain BG282 had the widest prey range on 7 plant pathogenic bacteria among the 17 prey strains tested. However, no predation occurred with strains of Azospirillum brasilense, Paenibacillus polymyxa, Pseudomonas fluorescens, P. putida, and Serratia marcescens that are associated with antibiosis or nitrogen fixation in the rice ecosystem. Identification was confirmed by the presence of typical bdelloplast in the prey cells of B. glumae and by a PCR assay using B. bacteriovorus-specific primers. Furthermore, 16S rDNA sequencing of the six bdellovibrio strains showed a homology range of 97.2% to 99.2% to the type strain of B. bacteriovorus.

• 한국물환경학회지
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• 제29권6호
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• pp.746-753
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• 2013

The aim of this study was to evaluate artificial fish shelter, which was known to increase prey survival and expand habitat space to improve species diversity and fish communities in a freshwater ecosystem. The experiment was performed at an outdoor test-bed for three months from 2011 by comparing the responses to adjustments in the volume of the artificial patch (juvenile fish shelter, JFS) in the control and experimental groups. Analysis of the environmental conditions over two periods (Period1 ~ 2) showed minor differences in the physichemical characteristics of water quality, phytoplankton, and zooplankton biomass, thus, allowing comparative analysis of feeding ecology. However, high water temperature conditions in Period1 ($25.6{\pm}2.0^{\circ}C$), affected the predation activity of the piscivorous fishes, Coreoperca herzi (C. herzi, size $89{\pm}4mm$). Survival rates of the prey fishes, Rhynchocypris oxycephalus (R. oxycephalus, size $29{\pm}1mm$), improved as the patch volume increased and were higher than those of the control group by 35.9 ~ 46.7%. Analysis showed that JFS reduced the chances of predator-prey encounter, and thereby minimized prey vulnerability.

• Kyungpook Mathematical Journal
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• 제48권3호
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• pp.503-514
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• 2008

We investigate a three-species food chain system with Lotka-Volterra functional response and impulsive perturbations. In [23], Zhang and Chen have studied the system. They have given conditions for extinction of lowest-level prey and top predator and considered the local stability of lower-level prey and top predator eradication periodic solution. However, they did not give a condition for permanence, which is one of important facts in population dynamics. In this paper, we establish the condition for permanence of the three-species food chain system with impulsive perturbations. In addition, we give some numerical examples.

• 대한수학회논문집
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• 제23권2호
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• pp.211-227
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• 2008

As a mathematical model proposed to understand the behaviors of interacting species, cross-diffusion systems with functional responses of prey-predator type are considered. In order to obtain $W^{1_2}$-estimates of the solutions, we make use of several forms of calculus inequalities and embedding theorems. We consider the quasilinear parabolic systems with the cross-diffusion terms, and without the self-diffusion terms because of the simplicity of computations. As the main result we derive the uniform $W^{1_2}$-bound of the solutions and obtain the global existence in time.

• Journal of applied mathematics & informatics
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• 제27권3_4호
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• pp.639-651
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• 2009

In this paper, we study a discrete Leslie-Gower one-predator two-prey model. By using the method of coincidence degree and some techniques, we obtain the existence of at least one positive periodic solution of the system. By linalization of the model at positive periodic solution and construction of Lyapunov function, sufficient conditions are obtained to ensure the global stability of the positive periodic solution. Numerical simulations are carried out to explain the analytical findings.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제17권2호
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• pp.129-138
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• 2013

A spatio-temporal models as systems of ODE which describe two-species Beddington - DeAngelis type predator-prey system living in a habitat of two identical patches linked by migration is investigated. It is assumed in the model that the per capita migration rate of each species is influenced not only by its own but also by the other one's density, i.e. there is cross diffusion present. We show that a standard (self-diffusion) system may be either stable or unstable, a cross-diffusion response can stabilize an unstable standard system and destabilize a stable standard system. For the diffusively stable model, numerical studies show that at a critical value of the bifurcation parameter the system undergoes a Turing bifurcation and the cross migration response is an important factor that should not be ignored when pattern emerges.

• 한국응용곤충학회지
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• 제32권1호
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• pp.61-67
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• 1993

점박이응애(Tetranychus urncae)의 알밀도(10~80), 공간분포〈집중 빛 균일분포) 및 서석면적크기 (3, 9, 16 $cm^2$)에 따른 긴털이리응애(Amblyseius longispinosus)의 가능반응을 연구하여 다음과 같은 결과를 얻었다. 긴털이리웅애의 점박이응애 발견효율은 밀도와 공간분포의 영향을 받았으나, 면적의 영향은 없었다. 포식량과 피식자간의 거리와는 매우 높은 역상관관계를 보였다(r=강.85; p=0.0001). 포식반응은 제2형의 기능반응을 보였다. 긴털이리응애의 기능반응은 random predator equation으로 잘 설명되었으며, 탐색률은 피식자의 집중분포하에서 반응면적에 따라 0.1030 - 0.1504였고 균일분포하에서는 0.0546~0.0276였다.