• Title/Summary/Keyword: agricultural insect pests

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In vitro Inhibition of Fungal Root-Rot Pathogens of Panax notoginseng by Rhizobacteria

  • Guo, Rongjun;Liu, Xingzhong;Li, Shidong;Miao, Zuoqing
    • The Plant Pathology Journal
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    • v.25 no.1
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    • pp.70-76
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    • 2009
  • The rhizobacteria of Panax notoginseng were isolated from six sites in Yanshan, Maguan and Wenshan Counties, Yunnan Province of China, and their antagonistic activity against P. notoginseng root-rot fungal pathogens was determined. Of the 574 rhizobacteria isolated, 5.8% isolates were antagonistic in vitro to at least one of the five pathogens, Cylindrocarpon didynum, Fusarium solani, Phytophthora cactorum, Phoma herbarum, and Rhizoctonia solani. The number of rhizo bacteria and the number that inhibited fungi differed depending on sampling sites and isolation methods. Rhizobacteria isolated from the site in Yanshan and Maguan showed more antagonistic effect than them in Wenshan. Heat treatment of rhizosphere soil at $80^{\circ}C$ for 20 min scaled the antagonists up to 14.0%. Antagonistic bacteria in the roots proportioned 3.9% of the total isolates. The most antagonistic isolates 79-9 and 81-4 are Bacillus subtilis based on their 168 rDNA sequence and biochemical and physiological characteristics. Identification and evaluation of antagonistic bacteria against P. notoginseng root-rot pathogens in the main planting areas improved our understanding of their distribution in rhizosphere soil. Furthermore these results indicated that the interactions between biocontrol agent and soil microbes should be seriously considered for the successful survival and biocontrol efficacy of the agents in soil.

Comparison on the Time of Occurrence of Major Rice Insect Pests Based on Growing Degree Day in Northern Part of Korean Peninsula (북방농업지대에서 유효적산온도를 이용한 벼 해충의 발생시기 비교)

  • Kim, Soon-Il;Uhm, Ki Baik;Jin, Da-Yong;Park, Hyung Man
    • Korean journal of applied entomology
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    • v.58 no.3
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    • pp.239-249
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    • 2019
  • This study was carried out to compare on the time of occurrence of 6 major rice insect pests [Lissorhoptrus oryzophilus Kusche, Oulema oryzae Kuwayama, Sogatella furcifera (Horvath), Nilaparvata lugens Stal., Cnaphalocrocis medinalis (Guenee), Mythimna separata Walker] in northern part of the Korean peninsula. Using growing degree days of the insects, we evaluated the number of occurrence generations and the time of occurrence. Over-wintering insects such as L. oryzophilus and O. oryzae showed different occurrence periods in northern regions. The occurrence period of the first generation adults was later in northeast regions than in Korean middle regions and more later both in northern alpines and in northern parts of east sea. In addition, the first adults of S. furcifera, N. lugens, C. medinalis, and M. separata occurred between June and early August. However, from late August to September, these insects showed the different occurrence periods in northern regions. Especially, the second adults of N. lugens were not occurred and the second to third generation adults of S. furcifera, C. medinalis, and M. separata showed similar occurrence properties. Based on these properties, the occurrence of major rice insect pests will be less in northeast regions, northern regions of east sea, northern inlands, and northern alpines of the Korean peninsula. However, comparing with their occurrences in northern regions of Gyenonggi and Gangwon provinces, the rice insect pests may show similar occurrence pattern in mid-korean mountains except for pyunggang and yangduk regions as well as in the southern and northern regions of Suyang-san.

Toxicity of various fruit tree extracts to five agricultural and four stored-product anthropod pests (다양한 과일나무에서 유래된 추출물의 농업해충 및 저장물해충에 대한 살충활성)

  • Lee, Sang-Guei;Park, Byeoung-Soo;Lee, Sung-Eun;Son, Jae-Gwon;Song, Cheol;Lee, Hoi-Seon
    • The Korean Journal of Pesticide Science
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    • v.5 no.4
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    • pp.27-32
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    • 2001
  • Methanol extracts from 43 materials of 17 fruit trees were tested for their insecticidal activities toward five agricultural and four stored-product anthropod pests. Efficacy varied with insect species, plant species, and tissue sampled. At a concentration of 2,500 ppm, strong activity was observed with extracts of Chaenomeles sinensis and Punica granatum seeds against Myzus persicae adult females, Vitis vinifera seeds against Nilaparvata lugens adults, Citrus junos, Citrus paradisi, Cucumis melo Linne var. reticulatus, Diospyros kaki, Malus pumila var. dulcissima, Prunug persica, and V. vinifera seeds against Plutella xylostella, Citrus sinensis seeds against Spedoptera litura larvae, and Ch. sinensis and V. vinifera against Tetranychus urticae adults. Against four stored-product insect pests at 50 ppm, seed extracts of Ch. sinensis and V. vinifera against Sitophilus oryzae adults, and Ch. sinensis, C. junos, D. kaki, and V. vinifera against Callosobruchus chinensis adults gave over 80% mortality. Extracts of all samples exhibited little and no activity against Lasioderma serricorne adults and Plodia interpunctella larvae.

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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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Monitoring Reports about Nine High Risk Insect Pests of South Korea in 2019 (2019년 한국의 고위험 해충 9종에 대한 예찰조사 보고)

  • Lee, Jieun;Lee, Hyobin;Kim, Sora;Kim, Hyojoong;Lee, Seunghwan;Hong, Ki-Jeong;Jung, Chuleui;Kim, Dong-soon;Park, Jong-Seok;Lee, Wonhoon
    • Korean journal of applied entomology
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    • v.59 no.3
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    • pp.203-207
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    • 2020
  • Monitoring about nine high risk insect pests, Aceria diospyri, Bactrocera dorsalis, Bactrocera minax, Bactrocera tsuneonis, Cydia pomonella, Lobesia botrana, Proeulia sp., Solenopsis invicta and Stephanitis takeyai, were carried out in seven regions from April to October in 2019. A total of 12,285 traps/visual scouting were investigated in 288 points of 87 local sites of seven regions, resulting the nine species, A. diospyri, B. dorsalis, B. minax, B. tsuneonis, C. pomonella, L. botrana, Proeulia sp., S. invicta, and S. takeyai, were not detected. This study have been carried out from 2018, and we established the nationwide monitoring system and secured a bridgehead for monitoring invasive insect pests passing the border.

Road-map for Environmental Friendly Integrated Pest Management(IPM) of Insect Pests on the Strawberry Vinyl-houses of Farmer's Field (딸기재배 하우스에서 발생하는 해충의 환경친화적 종합적방제를 위한 로드맵)

  • Lee, D.H.;Jo, C.W.;Park, C.R.;Lee, H.J.;Kang, E.J.;Seok, H.B.;Seo, M.J.;Kim, H.Y.;Kim, Y.H.;Yu, Y.M.;Youn, Y.N.
    • Korean journal of applied entomology
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    • v.47 no.3
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    • pp.273-286
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    • 2008
  • Road-map for the environmental friendly integrated pest management(IPM) of insect pests was drawn up on the strawberry vinyl-houses of farmer's field. Major insect pests were occurred Tetranychus urticae and Aphis gossypii during the strawberry plant seeding in the vinyl house and open field. Also, same insect pests were occurred in the vinyl house during harvesting season of strawberry. For the control of T. urticae and A. gossypii, Phytoseiulus persimilis and Aphidius colemani as natural enemies were input to the vinyl house, respectively. However, because these natural enemies could not control insect pest populations, acaricide and insecticide were sprayed. Then natural enemies were input again in the vinyl house. Natural enemies could not endure the intense cold and differences of temperature and relative humidity between day and night during strawberry harvesting season. So, their behavior and control activity of pests were more decrease than pests. Firstly, natural enemies are input in the vinyl house during the early breeding season of strawberry, secondly, acaricides and insecticide are sprayed for the control of mites and aphids, respectively, during the middle breeding season in the hard winter. Finally, natural enemies are re-input in the vinyl house during the middle and late breeding season.

Patterns of Insect Pest Occurrences and Dasineura oxycoccana Johnson in Blueberry Farms in Jeonbuk Province (전북지역 블루베리에 발생하는 해충종류와 블루베리혹파리 발생양상)

  • Lim, Ju-Rak;Kim, Eun-Ju;Moon, Hyung-Cheol;Cho, Chong-Hyeon;Han, Soo-Gon;Kim, Hee-June;Song, Young-Ju
    • Korean journal of applied entomology
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    • v.55 no.1
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    • pp.45-51
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    • 2016
  • Thirty-seven species of insect pests were surveyed on different area blueberry farms in Jeonbuk province during 2013~2014. Six principal insect pests were found, including Dasineura oxycoccana Johnson, Aphis gossypii Glover, Scirtothrips dorsalis Hood, Ricania sp., Hyphantria cunea Drury, and Latoia consocia Walker. A. gossypii infestation was severe at Iksan and Jinan in middle May. S. dorsalis infestation was severe at all surveyed area in early June, which is the flowering season, and the degree of damage caused was higher in young plants. Ricania sp. was abundant in Jinan and Sunchang, and then appeared to spread across all areas in Jeonbuk. H. cunea had a tendency to concentrate in Iksan during June. Five species of Limacodidae was found, including L. consocia, which was dominant in all areas surveyed, with densities higher then those of the others four species. The degree of damage due to D. oxycoccana was higher in the plain areas (Iksan) than in the middle-mountain areas (Jinan, Sunchang). The rate of damage was 60~78% higher in young plant stages (i.e., those under 3 years of tree age) than in those over 5 years old (30~50%). Moreover, the rate of damage observed in greenhouses was 50~80% higher than that observed in the field (30~40%).

Discovery of Thaumaglossa rufocapillata Redtenbacher (Dermestidae, Coleoptera) from Mantis oothecae in Korea and its complete mitochondrial genome

  • Gyu-Dong Chang;Jaeil Shim;Sangmin Ji;Jeong-Hun Song
    • International Journal of Industrial Entomology and Biomaterials
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    • v.47 no.2
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    • pp.115-125
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    • 2023
  • The insect industry in Korea is currently undergoing steady expansion. Among the various insects kept as pets or for educational purposes, four mantis species, including Hierodula patellifera (Audinet-Serville), Tenodera angustipennis Saussure, Tenodera sinensis Saussure, and Statilia maculata (Thunberg), are becoming increasingly popular, leading to higher demand. As we aimed to raise mantises, we collected oothecae, some of which were found to be parasitized by dermestid beetles. These parasitoids have been unequivocally identified as Thaumaglossa rufocapillata Redtenbacher based on morphological characters. A diagnosis, habitus photographs, and illustrations of diagnostic characters are provided to facilitate identification. We also present the complete mitochondrial genome (mitogenome) sequence of T. rufocapillata for providing fundamental data for research aimed at controlling pests in the insect industry.