• Title/Summary/Keyword: insect pests

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Rice Insects : The Role of Host Plant Resistance in Integrated Management Systems

  • Heinrichs, E.A.
    • Korean journal of applied entomology
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    • v.31 no.3
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    • pp.256-275
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    • 1992
  • Insects are among the most important abiotic and biotic constraints to rice production. National rice research programs are in various stages in the development and implementation of integrated pest management (IPM) stratagies for rice insect control. Among the various control tactics, insect resistant cultivars are sought as the major tactic in rice IPM. Through the activities of interdisciplinary teams of scientists significant progress has been made in the development and release of insect resistant cultivars to farmers. Because of its compatibility with other control tactics insect resistance has proven to fit well into the IPM approach to rice insect control agents and minimize the need for insecticide applications. The development of biotypes which overcome the resistance in rice plants has been a significant constraint in the breeding of rice for resistance to insects. Most notable examples in Asia are the green leafhopper, Nephotettix virescens, brown planthopper, Nilaparvata lygens and the Asian rice gall midge, Orseolia oryzae. The current breeding stratege is to develop rice cultivars with durable resistance on which virulent biotypes cannot adapt. In spite of the significant progress made in the breeding of insect resistant cultivars there are still numerous important rice insect species for which host plant resistance as a control tactic has not been fully utilized. Advances in biotechnology provide promise of solving some of the problems that have limited the use of host plant resistance as a major tactic in the integrated management of rice insect pests.

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A New Disinfestation Approach Against Some Greenhouse Pests Using Ethyl Formate Fumigation (훈증제 에틸포메이트를 이용한 몇 가지 시설하우스 해충에 대한 새로운 방제 전략)

  • Kwon, Tae-Hyung;Jeong, In-Hong;Lee, Byung-Ho;Park, Chung Gyoo
    • Korean journal of applied entomology
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    • v.58 no.4
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    • pp.341-345
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    • 2019
  • Ethyl formate (EF) is a rapid kill, environmentally safe, and low mammalian toxicity fumigant, registered to disinfest quarantine insect pests from imported agricultural products. A new concept for controlling insect pests of agricultural crops was tested in a fumigation chamber with EF. Control efficacy of and phyto-toxicity due to EF fumigation were evaluated against four pests (Thrips palmi, Bemisia tabaci, Myzus persicae, and Tetranychus urticae) and on seedlings of four fruit vegetables (FVs; yellow melon, cucumber, tomato, and pepper). Ethyl formate fumigation at a dose of 1.5 g m-3 for 12 h produced >93.3% mortality in T. palmi, B. tabaci, and M. persicae. However, T. urticae was tolerant to fumigation, showing only 20% mortality at 2.0 g m-3. In terms of concentration × time (CT) products, at least 8.9 g·h m-3 CT at 20 ± 1.5℃ was needed to achieve > 90% mortality against the three susceptible insect pests. Fumigation at 1.5 g m-3 for 12 h caused no phyto-toxicity to any of the four FV seedlings. Ethyl formate application, as a new disinfestation method in greenhouses, could be an alternative to reduce the use of conventional insecticides. However, further studies are needed to determine the efficacy of this method at different pest developmental stages and in different greenhouse environments. Additionally, research is needed to elucidate the phyto-toxicity of EF application at different growing stages of a wide variety of crops.

Development of Basic Research for Establishing the Apple IPM System in Korea: Dr. Lee Soon-Won's Research Case (한국형 사과 병해충종합관리(IPM) 체계 수립을 위한 기초연구의 전개: 이순원 박사의 연구 사례)

  • Ahn, Jeong Joon;Oh, Hyeonseok;Choi, Kyung San;Choi, Kyung-Hee;Do, Yun-Su;Lee, Sun-Young;Lee, Dong-Hyuk
    • Korean journal of applied entomology
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    • v.60 no.1
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    • pp.1-13
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    • 2021
  • The concept of integrated pest management (IPM) first developed in the 1950s, and the concept of economic control via pest management was established in the 1960s. Research on IPM began in the United States and Europe, and IPM studies in Korea started with citrus insects and paddy field pests following the distribution of high-yield varieties of rice. Apple IPM in Korea began with research on pest control using chemical pesticides and pesticides resistant to insect pests, studies on the ecology of insect pests and their natural enemies, and the exploitation of sex pheromones on insect pests. Since the 1990s, IPM research and field projects have been carried out simultaneously for farming households. In the 2000s, the development of pest monitoring and forecasting models centered on mating disturbances, database programs for pests, and networks for sharing information. IPM technology has expanded via the development of unmanned forecasting systems and automation technologies in the 2010s.

Research Status and Future Subjects to Predict Pest Occurrences in Agricultural Ecosystems Under Climate Change (기후변화에 따른 농업생태계 내 해충 발생 예측을 위한 연구 현황 및 향후 과제)

  • Jung, Jong-Kook;Lee, Hyoseok;Lee, Joon-Ho
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.16 no.4
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    • pp.368-383
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    • 2014
  • Climate change is expected to affect population density, phenology, distribution, morphological traits, reproduction and genetics of insects, and even in the extinction of insects. To develop novel research subjects for predicting climate change effect, basic information about biological and ecological data on insect species should be compiled and reviewed. For this reason, this study was conducted to collect the biological information on insect pests that are essential for predicting potential damage caused by insect pests in future environment. In addition, we compared domestic and foreign research trends regarding climate change effect and suggested future research subjects. Domestic researchers were rather narrow in the subject, and were mostly conducted based on short-term monitoring data to determine relationship between insects and environmental variables. On the other hand, foreign researches studied on various subjects to analyze the effect of climate change, such as changes in distribution of insect using long-term monitoring data or their prediction using population parameters and models, and monitoring of the change of the insect community structure. To determine change of the phenology, distribution, overwintering characteristics, and genetic structures of insects under climate change through development of monitoring technique, in conclusion, further researches are needed. Also, development of population models for major or potential pests is important for prediction of climate change effects.

Antimicrobial Active Substances from Entomopathogenic Fungi (Various Applications of Entomopathogenic Fungi)

  • Shin, Tae Young;Woo, Soo Dong;Kim, Jeong Jun
    • 한국균학회소식:학술대회논문집
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    • 2016.05a
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    • pp.13-13
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    • 2016
  • Insects constitute the largest and most diverse group of animals in the world. They also serve as the hosts or nutrient sources for an immense assemblage of pathogens, parasites, and predators. More than 700 fungal species from 100 genera have adopted an entomopathogenic lifestyle. Although entomopathogenic fungi were studied as only biocontrol agents against a variety of pests in various countries, it has been recently focused their additional roles in nature. They are antagonists to/against plant pathogens, endophytes, and possibly even plant growth promoting agents. The potential antimicrobial effect against fungal plant pathogens by an isolate of entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have been reported since late 1990s, but wasn't reported pathogenicity of the isolate against pests. Later, a Canadian Lecanicillium sp. isolate and L. longisporium isolated from Vertalec$^{(R)}$ showed simultaneous control effect against both aphid and cucumber powder mildew. Therefore, the antimicrobial activities of 342 fungi isolates collected from various regions and conditions in Korea were evaluated against plant pathogenic fungus Botrytis cinerea using dual culture technique on agar plate. As a result, 186 isolates (54.4%) shown the antifungal activity against B. cinerea. The culture filtrates of selected fungi completely suppressed the growth of the microorganisms, indicating that suppression was due to the presence of antimicrobial substances in the culture filtrate. Mode of action of these fungi against insect involves the attachment of conidia to the insect cuticle, followed by germination, cuticle penetration, and internal dissemination throughout the insect. During infection process, secreted enzymes, proteinous toxins, and/or secondary metabolites secreted by entomopathogenic fungi can be used to overcome the host immune system, modify host behavior, and defend host resources. Recently, secondary metabolites isolated from entomopathogenic fungi have been reported as potential bioactive substances. Generally, most of bioactive substances produced by entomopathogenic fungi have reported low molecular weight (lower than 1,000 g/mol) as peptide and, in contrast the high molecular weight fungal bioactive substances are rare. Most substances based on entomopathogenic fungi were shown antimicrobial activity with narrow control ranges. In our study we analyzed the antimicrobial substances having antagonistic effects to B. cinerea. Antimicrobial substances in our fungal culture filtrates showed high thermostability, high stability to proteolytic enzymes, and hydrophilicity and their molecular weights were differed from substance. In conclusion, entomopathogenic fungi showed pathogenicity against insect pests and culture filtrate of the fungi also shown to antimicrobial activity. In the future, we can use the entomopathogenic fungi and its secondary metabolites to control both insect pest control and plant pathogenic fungi simultaneously.

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Fungicidal and insecticidal activities of various grain extracts against five insect pests and six phytopathogenic fungi (다양한 잡곡 추출물의 살균.살충활성)

  • Lee, Hoi-Seon;Choi, Gyung-Ja;Cho, Kwang-Yun;Lee, Sang-Gil;Ahn, Young-Joon
    • The Korean Journal of Pesticide Science
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    • v.4 no.3
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    • pp.7-14
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    • 2000
  • Methanol extracts from 21 grains were tested for fungicidal activities against six phytopathogenic fungi and for insecticidal activities toward five insect pests in a greenhouse. The efficacy varied with both the plant pathogen/insect pest and grain species used. Potent fungicidal activity at 5 mg/pot, were produced from extracts of Elymus sibiricus and Hordeum vulgare var. nudum against Pyricularia grisea and Erysiphe graminis and these of Sesamum indicum (W) and Triticum aestivum against Puccinia recondita and Erysiphe graminis. At 2,500 ppm, potent insecticidal activities were exhibited from the extracts of Fagopyrum esculentum against Myzus persicae and Ischaemum crassipes, and these of Oryzo sativa var. glutinosa, Panicum miliaceum, Setaria italica, Sorghum bicolor, and T. aestivum against Tetranychus urticae. All grain extracts revealed weak or no fungicidal and insecticidal effect against Phytophthora infestans, Plutella xylostella and Spodoptera litura. As a naturally occurring fungicide and insecticide, grain-derived materials described could be useful as new fungicidal and insecticidal products against phytopathogenic fungi and insect pests.

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Test of Larvicidal Effect of Some Commercial Natural Products on Lepidoptran Plutella xylostella and Spodoptera litura Larvae

  • Jeong, Hyung-Uk;Im, Hyun-Hwak;Chang, Sung-Kwon;Paik, Chae-Hoon;Han, Tae-Ho;Kim, In-Seon;Kim, Ik-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.15 no.1
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    • pp.87-91
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    • 2007
  • A diverse kind of environment-friendly agricultural materials(EFAM) for the control of insect pests is on the market. These EFAMs are a part of essential sources for the accomplishment of successful, sustainable, and environment-friendly agriculture. Thus, accurate information of these EFAMs is one that required for the success of environment-friendly agriculture, but, in reality, still appropriate information is absolutely in shortage. In this study, we, therefore, tested the efficacy of commercial EFAMs against two lepidopteran insect larvae, the diamondback moth Plutella xylostella(Lepidoptera: plutellidae) and the tobacco cutworm Spodoptera litura(Lepidoptera: Noctuidae). After the two insect pests were successfully stabilized in indoor environment the larvicidal activity was tested at $24{\pm}1^{\circ}C$, relative humidity(RH) of $60{\pm}5%$, and a photoperiod of 16L:8D, and mortality was determined 48 hrs after EFAMs are treated. The EFAMs that showed more than 90% of larvicidal activity were each six among 16 against both P. xylostella and S. litura and only three of them showed consistent larvicidal activity against both species, signifying species specificity of EFAMs and importance of selection of proper EFAMs depending on target insect pest.