• Title, Summary, Keyword: beet armyworm

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Biological Control of Beet Armyworm, Spodoptera exigua(Lepidoptera: Noctuidae) with Entomopathogenic Nematodes(Steinernematid and Heterorhabditid) in Greenhouse (시설재배지에서 곤충병원성 선충, Steinernematid와 Heterorhabditid를 이용한 파밤나방(Spodoptera exigua)의 생물적 방제)

  • Kim, Hyeong-Hwan;Cho, Sung-Rae;Lee, Dong-Woon;Lee, Sang-Myeong;Choo, Ho-Yul
    • The Korean Journal of Pesticide Science
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    • v.10 no.4
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    • pp.335-343
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    • 2006
  • Five strains of Korean entomopathogenic nematodes(EPN), steinernematids and heterorhabditids(Steinernama carpocapsae GSN1, Steinernema sp. GSNUS-10, Steinernama sp. GSNUS-14, Heterorhabditis bacteriophora Hamyang, Heterorhabditis sp. GSNUH-1) were evaluated and tried in petri dish, pot, and vegetable greenhouses for environmentally friendly control of beet armyworm, Spodoptera exigua. $LC_{50}$ values of five EPN strains against beet armyworm was different depending on nematode strain and beet armyworm instar. $LC_{50}$ value of Steinernema carpocapse GSN1(GSN1) was 3.8-5.1 infective juveniles(Ijs) in 2nd to 4th instars of beet armyworm. Pathogenicity of five EPN strains against beet armyworm different in nematode strain, concentration, application times, and vegetable species in pot and greenhouse. Steinernema spp. was more effective than Heterorhabditis spp. against beet armyworm. Two or three times of applications of EPN were found to be effective regardless of nematode strain and concentration in pot and greenhouse. ENP showed different reactions on vegetable species. Efficacy of EPN was higher on Chinese cabbage than that on cabbage and kale. GSN1 was one of the most effective nematodes and 100,000 infective juveniles per $m^2$(720,000 Ijs/$7.2m^2=1{\times}10^9$Ijs/ha) resulted in higher mortality in greenhouse.

Seasonal Fluctuation of Beet Armyworm, Spodoptera exigua (Hubner), Adult and Larva (파밤나방 성충 및 유충의 발생)

  • 고현관;최재승;엄기백;최기문;김정화
    • Korean journal of applied entomology
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    • v.32 no.4
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    • pp.389-394
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    • 1993
  • Seasonal fluctuation of Beet armyworm, Spodoptem exigua, adults and larvae were momtored by pheromone trap and direct obseration in the welsh onion field, respecLively. Adult peaked on mid~late November and occurred 4 Limes a year by pheromone trap at Yesan, 1990. There were 3 peaks a year at Asan, 1991. The highest number of adults were caught on early September. In Suwon, the yearly number of adults caught by pheromone trap was high in the order of 1990, 1991, and 1992. In 1992, the moLh was initily caught on mid April by pheromone trap at Koheung, Chonnam, and it vms 3 month earlier than that at Suwon. The larvae of beet armyworm at welsh onion field at Asan, 1991 was first found on late June and gradually increased until mid September. The density at peak occurrence was about 20 individual per 100 hills of welsh onion. The peak of the larvae appeared 20 days after peak emergence of adult. It is expected that there are 4 times of occurrence when the first egg of beet armyworm IS laid on mid May at Suwon. It takes 48, 25, 23, and 58 days to complete 1st, 2nd, 3rd. and 4th generation, respectively.

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Insecticidal Activity of Metarhizium anisopliae FT83 against the Different Stages of Beet Armyworm, Spodoptera exigua (곤충병원성 곰팡이 Metarhizium anisopliae FT83의 파밤나방 생육단계별 살충활성)

  • Han, Ji Hee;Kim, Jeong Jun;Lee, SangYeob
    • The Korean Journal of Pesticide Science
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    • v.18 no.4
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    • pp.417-421
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    • 2014
  • The beet armyworm, Spodoptera exigua is pest which is difficult to control. For eco-friendly beet armyworm managements, we isolated entomopathogenic fungi from soil samples by insect-bait method using Tenebrio molitor and conducted bioassay to larvae of beet armyworm. The result of bioassay, a selected strain Metarhizium anisopliae FT83 caused 100% mortality against first ~ third instar larva of S. exigua at $1{\times}10^8conidia/ml$ and medial lethal time ($LT_{50}$) were 0.5 days, 2.6 days and 2.5 days respectively. Mortality against fourth and fifth larvae were $83.3{\pm}6.2%$ and $86.0{\pm}5.7%$ and medial lethal time ($LT_{50}$) were 4.2 days and 3.6 days respectively. Mortality against pupae and eggs of S. exigua were 100%. M. anisopliae FT83 showed high virulence at all developmental stages of S. exigua.

Virulence of Entomopathogenic Fungi Metarhizium anisopliae and Paecilomyces fumosoroseus for the Microbial Control of Spodoptera exigua

  • Han, Ji Hee;Jin, Byung Rae;Kim, Jeong Jun;Lee, Sang Yeob
    • Mycobiology
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    • v.42 no.4
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    • pp.385-390
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    • 2014
  • The beet armyworm Spodoptera exigua (Lepidoptera: Noctuidae) is difficult to control using chemical insecticides because of the development of insecticide resistance. Several pest control agents are used to control the beet armyworm. Entomopathogenic fungi are one of the candidates for eco-friendly pest control instead of chemical control agents. In this study, among various entomopathogenic fungal strains isolated from soil two isolates were selected as high virulence pathogens against larva of beet armyworm. Control efficacy of fungal conidia was influenced by conidia concentration, temperature, and relative humidity (RH). The isolates Metarhizium anisopliae FT83 showed 100% cumulative mortality against second instar larvae of S. exigua 3 days after treatment at $1{\times}10^7$ conidia/mL and Paecilomyces fumosoroseus FG340 caused 100% mortality 6 days after treatment at $1{\times}10^4$ conidia/mL. Both M. anisopliae FT83 and P. fumosoroseus FG340 effectively controlled the moth at $20{\sim}30^{\circ}C$. M. anisopliae FT83 was significantly affected mortality by RH: mortality was 86.7% at 85% RH and 13.4% at 45% RH. P. fumosoroseus FG340 showed high mortality as 90% at 45% RH and 100% at 75% RH 6 days after conidia treatments. These results suggest that P. fumosoroseus FG340 and M. anisopliae FT83 have high potential to develop as a biocontrol agent against the beet armyworm.

Toxicological Effects of Some Insecticides against Welsh Onion Beet Armyworm (Spodoptera exigua) (Metaflumizone을 포함한 몇 가지 약제의 파밤나방(Spodoptera exigua)에 대한 독성검정)

  • Kang, E.J.;Kang, M.G.;Seo, M.J.;Park, S.N.;Kim, C.U.;Yu, Y.M.;Youn, Y.N.
    • Korean journal of applied entomology
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    • v.47 no.2
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    • pp.155-162
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    • 2008
  • The Welsh onion beet armyworm, Spodoptera exigua (Hubner), has attacked Welsh onion and is now the most important pest of Welsh onion in southwestern Korea. The beet armyworm has a wide host range, occurring as a serious pest of vegetable and fields. The relatively high abundance of beet armyworm has stimulated frequent application of insecticides to foliage. Insecticide resistance is a major problem in management of this insect. Accordingly, pesticide application for the control of beet armyworm was tried in both the open field and in laboratory, using 4 synthetic compounds such as metaflumizone and chlorfenapyr, indoxacarb, flufenoxuron, emamectin benzoate. In the laboratory, each developmental stages from eggs, larva to pupa was tested against 4 insecticides. Against the eggs of welsh onion beet armyworm, there was no significantly different with each other. These tested chemicals no killing effect to eggs. However, the population of 1st larva hatched from eggs were reduced because they eaten the egg shell with residual insecticides. The tested insecticides were taken very high mortalities to 1st to 3rd larva of Welsh onion beet armyworm. Otherwise, there were decreased the death rate from 4th to 6th larva. On the other hand, their value of control effects were relatively good against Welsh onion beet armyworms in the field between 87.2 and 90.5% on 10 days after insecticide application.

Characteristics and Virulence Assay of Entomopathogenic Fungus Metarhizium anisopliae for the Microbial Control of Spodoptera exigua (파밤나방의 생물적 방제를 위한 곤충병원성 곰팡이 Metarhizium anisopliae의 특성 및 병원성 검정)

  • Han, Ji Hee;Kim, Hyeonggyeong;Leem, Hun Tae;Kim, Jeong Jun;Lee, SangYeob
    • The Korean Journal of Pesticide Science
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    • v.17 no.4
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    • pp.454-459
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    • 2013
  • Beet armyworm, Spodoptera exigua is difficult to control using chemical insecticides because of the fast development of insecticide resistance. For eco-friendly beet armyworm managements, various control agents are required. Entomopathogenic fungus is one of the promise control agents as an alternative to chemical control agent. We isolated entomopathogenic fungi from soil samples of Yangpyeong, Gyeonggi-do by insect-bait method using Tenebio molitor and conducted bioassay to larva of beet armyworm. The result of bioassay, a selected strain FT83 showed 100% mortality against third instar larva of S. exigua. On the basis of morphological characteristics and analysis of 18srRNA sequence for ITS, the strain FT83 was identified as a Metarhizium anisopliae. The mortality of beet armyworm showed $81.6{\pm}9.3%$ at $1{\times}10^6$ conidia/ml, 100% at $1{\times}10^7$ conidia/ml and 100% at $1{\times}10^8$ conidia/ml respectively. Therefore, we recommend to proper control efficacy against S. exigua in which more than $1{\times}10^7$ conidia/ml suspension of M. anisopliae FT83.

Environment-Friendly Control of Beet Armyworm, Spodoptera exigua (Noctuidae: Lepidoptera) to Reduce Insecticide Use (농약 사용 저감화를 위한 환경 친화적인 파밤나방(Spodoptera exigua)의 방제)

  • Jin, Da-Yong;Paek, Seung-Kyung;Kim, Jin-Su;Choi, Su-Yeon;Park, Chan;Kim, Tae-Hwan;Jin, Na-Young;Jung, Sun-Young;Youn, Young-Nam;Yu, Yong-Man
    • Korean journal of applied entomology
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    • v.48 no.2
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    • pp.253-261
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    • 2009
  • For the environment-friendly control of beet armyworm, Spodoptera exigua, in spring onion fields, we have examined an alternative application method. Twenty-five insecticides registered for spring onion were tested for control effect against the beet armyworm in the laboratory, then the best 9 chemical and a single biological insecticides were selected and compared with 2 new isolates of Bacillus thuringiensis in a polyvinyl house. After that, 4 chemical and 3 B. thuringiensis treatments were used in the field for the control of beet armyworm in the spring onion. Two application methods are used: one is triple treatments with the same chemical and the other is alternative application with different chemicals and B. thuringiensis for 7 days intervals. Indoxacarb WP - chlorfluazuron EC - B.t. var. kurstaki CAB141 and indoxacarb WP - methoxyfenozide + spinosad SC - Chlorfluazuron EC - B.t. var. aizawai CAB109, B.t. var. kurstaki CAB141 showed greater than 78% mortality of beet armyworm larvae and greater than 43% damage decrease in spring onions infested by beet armyworm. These results showed that alternative applications had higher control effect than any other applications. It was suggested that alternative applications with microbial biological agents such as B. thuringiensis might minimize the development of insecticide resistance and might be used as the environment-friendly control of the beet armyworm.

Analysis of the Isozyme Loci of the Beet Armyworm, Spodoptera exigua(H bner) (파밤나방(Spodoptera exigua(H bner))의 동위효소 유전좌위 분석)

  • 김용균;김경성
    • Korean journal of applied entomology
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    • v.37 no.1
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    • pp.19-22
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    • 1998
  • Number of loci, allele frequencies, and subunit structures of 17 kinds of isozymes were analyzed in a laboratory strain of the beet armyworm, Spodoptera exigua (Hubner) to get genetic markers. These isozymes had 30 loci with 21 polymorphic (70.0% polymorphism); effective number of alleles per locus, average heterozygosity (H,), and inbreeding coefficient (F) were 2.52, 32.8%, and 2 1.0%, respectively.

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Spatial Distribution Pattern of Beet Armyworm, Spodoptera exigua(Hubner), Larvae in the Welsh Onion Field (파 포장에서 파밤나방 유충의 공간분포)

  • 고현관;최재승;엄기백;최귀문;김정화
    • Korean journal of applied entomology
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    • v.32 no.2
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    • pp.134-138
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    • 1993
  • Larval densities and spatial distribution patterns of beet armyWorm, Spodoptera exigua, were studied in the welsh onion field located in Asan from June to November, 1991. During the period, there were two denslty-peaks;mid August and mid~late September. The larvae showed clumped distribution patterns. but the patterns changed into random as larval density decreased in Oct.ober. Each larval instar showed clumped pattern expect 6th instar surveyed on September 25, which distributed in a random pattern. The larval distribution pattern were also influenced by the host plants;clumped pattern on such host. as red pepper and welsh onion, versus random pattern on such hosts as chrysanthemum, peanut and soybean.

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