• Title/Summary/Keyword: beet armyworm

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Flight Activity and Injury Characteristics of Beet Armyworm, Spodoptera exigua(Hubner), (Lepidoptera: Noctuidae) in Southern Region of Korea (남부지방에서 파밤나방의 비산활동 및 가해특성)

  • 박종대;고현관;이재휴;이운직;김규진
    • Korean journal of applied entomology
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    • v.30 no.2
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    • pp.124-129
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    • 1991
  • This study investigated seasonal occurrence and daily flight activity using synthetic sex pherom mone and injury characteristics of 야et armyworm, Spodoptera exigua in Chonnam area of K Korea in 1990. Male adults were attracted to phermone trap from mid-June to late November w with the peaks at mid-late August, mid-late September and early-mid November in vinyl i house and also were attracted from mid October to late November in field. Primary peak of occurrence in vinyl house was 20 days sooner than field. It seems to have 6 generations a year in C Chonnam region based on the estimation of larval biomass. Daily male flight was active from m midnight to before sunrise with the peak at 4-6 A.M .. In injury characteristics at various host plants, damage was great in early growing stage at below 10 cm of plant height in Allium fistulsum. Chrysanthemum morifolium was damaged at mostly upper part of leaves reaching to m the extent up to 70%. In case of Gypsophila paniculata, plants injured at early growing stage do n not grow and flower normally.

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Control of the Beet Armyworm, Spodoptera exigua Hubner (Lepidoptera: Noctuidae), using Synthetic Sex Pheromone. II. Control Using Mating Disruption dispensers in Field (합성 성페로몬에 의한 파밤나방의 방제. II. 교미교란에 의한 방제)

  • 박종대;김규진
    • Korean journal of applied entomology
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    • v.34 no.3
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    • pp.169-173
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    • 1995
  • This study was conducted to investigate control effects against Spodoptera exigua Hubner in field using mating disruption dispensers of synthetic sex pheromone during 1993 and 1994. Denisities in egg and larva of Spodoptera exigua in field treated with the dispensers was 1.9% level of that without dispensers in welsh onion, 12.5% in red pepper and 4.4% in potato in 1993. Also 5.9% and 5.2% were counted from 10 ha and 20 ha of welsh onion field compared. Control value in Fields with dispensers were maintained at 80% level in 10 ha and 90% level in 20 ha until October.

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Control of Diseases and Insects for Pesticide-free Cultivation of Leafy Vegetables (엽채류 유기재배의 병해충 관리)

  • Seo, Young-Ho;Cho, Byoung-Ouk;Choi, Jun-Keun;Kang, An-Seok;Jeong, Byung-Chan
    • Korean Journal of Organic Agriculture
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    • v.17 no.2
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    • pp.253-264
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    • 2009
  • This study was conducted to establish agricultural practices to control diseases and insects for chemical pesticide-free cultivation of leafy vegetables. Two diseases, gray mold(Botrytis cinerea) and soft rot(Erwinia carotovora), on lettuce were reduced by controlling temperature and humidity using air-circulation fan. The aphidophagous lady beetle(Harmonia axyridis) and primary parasitoids(Aphidius colemani) showed activity to control aphids density on Chinese cabbage. Co-application of cooking oil and yolk mixture (COY) and BT(Bacillus thuringiensis) decreased diseases including soft rot(Erwinia carotovora), downy mildew(Peronospora brassicae Gaumann), and powdery mildew(Eryslphe polygoni), and insects such as diamondback moth(Plutella xylostella) and beet armyworm(Spodoptera exigua Hubner). Neem extract treatment reduced downy mildew(Peronospora destructor) on Welsh onion.

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Nucleopolyhedrovirus Induces Suppressor of Cytokine Signaling in the Beet Armyworm, Spodoptera exigua

  • Noh Mi-Young;Jo Yong-Hun;Kim Seon-Am;Lee Yong-Seok;Bang In-Seok;Kim Seon-Gon;Park Jong-Dae;Chun Jae-Sun;Seo Sook-Jae;Han Man-Deuk;Kim Ik-Soo;Han Yeon-Soo
    • International Journal of Industrial Entomology and Biomaterials
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    • v.12 no.2
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    • pp.63-67
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    • 2006
  • Suppressor of cytokine signaling (SOCS) is known to playa key role as a negative feedback regulator in JAK/STAT signaling cascade in innate immunity. Our laboratory has recently been interested in elucidating the interactions between Spodoptera exigua (Se) and SeNPV. This context leads us to clone and characterize SeSOCS that may have important functions in response to SeNPV infection. Using the RT-PCR and TA cloning approach, we found a partial fragment (416 bp) of SeSOCS. Blast search and multiple alignment data showed that it has a homology to various insects such as Anopheles gambiae (78%), Aedes aegypti (75%), Drosophila melanogastar (77%), Mus musculus (69%), and Homo sapiens (69%). Temporal induction patterns of SeSOCS were analysed after being immune-challenged with either NPV or laminarin. It showed that the level of SeSOCS mRNA was strongly induced in a biphasic manner in response to SeNPV and laminarin, respectively. It seems that SOCS, a negative regulator of JAK/STAT signaling system is also present in S. exigua and may playa role in innate immunity albeit its precise role should be further elucidated at the molecular and cellular level in the early phase of SeNPV infection in larvae.

Identification of an Entomopathogenic Bacterium, Serratia sp. ANU101, and Its Hemolytic Activity

  • Kim, Yong-Gyun;Kim, Keun-Seob;Seo, Ji-Ae;Shrestha, Sony;Kim, Hosanna-H.;Nalini, Madanagopal;Yi, Young-Keun
    • Journal of Microbiology and Biotechnology
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    • v.19 no.3
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    • pp.314-322
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    • 2009
  • Four different bacterial colonies were isolated from an old stock of an entomopathogenic nematode, Steinernema monticolum. They all showed entomopathogenicity to final instar larvae of beet armyworm, Spodoptera exigua, by hemocoelic injection. However, they varied in colony form, susceptibility to antibiotics, and postmortem change of the infected host insects. Biolog microbial identification and 16S rDNA sequence analyses indicate that these are four different species classified into different bacterial genera. Owing to high entomopathogenicity and a cadaver color of infected insect host, Serratia sp. was selected as a main symbiotic bacterial species and analyzed for its pathogenicity. Although no virulence of Serratia sp. was detected at oral administration, the bacteria gave significant synergistic pathogenicity to fifth instar S. exigua when it was treated along with a spore-forming entomopathogenic bacterium, Bacillus thuringiensis. The synergistic effect was explained by an immunosuppressive effect of Serratia sp. by its high cytotoxic effect on hemocytes of S. exigua, because Serratia sp. caused septicemia of S. exigua when the bacterial cells were injected into S. exigua hemocoel. The cytotoxic factor(s) was present in the culture medium because the sterilized culture broth possessed high potency in the cytotoxicity, which was specific to granular cells and plasmatocytes, two main immune-associated hemocytes in insects.

Biochemical Analysis of Physiological Stress Induced by High Frequency Sound Treatment in the Beet Armyworm, Spodoptera exigua (고주파 처리에 따른 파밤나방(Spodoptera exigua)의 생리적 스트레스의 생화학적 분석)

  • Kim, Yong-Gyun;Son, Ye-Rim;Seo, Sam-Yeol;Park, Bok-Ri;Park, Jung-A
    • Korean journal of applied entomology
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    • v.51 no.3
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    • pp.255-263
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    • 2012
  • High frequency sounds disrupt physiological processes, such as feeding behavior, development and immune responses of Spodoptera exigua. We analyzed high frequency sounds with respect to biochemical changes in S. exigua. High frequency sound (5,000 Hz, 95 dB) suppressed protein synthesis and secretion of midgut epithelium. It also significantly inhibited a digestive enzyme activity of phospholipase $A_2$. The gene expression of three different heat shock proteins and apolipophorin III was altered, particularly in midgut tissue in response to high frequency sound treatments. High frequency sound treatments significantly increased sugar and lipid levels in hemolymph plasma. These results suggest that high frequency sounds are a physiological stress that induces biochemical changes in S. exigua.

몇 가지 PBTs (Persistent, Bioaccumulative, Toxic Chemicals)가 생태계 곤충에 미치는 영향

  • Lee Seun Yeong;Kim Yong Gyun
    • Proceedings of the Korea Society of Environmental Biology Conference
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    • 2002.11a
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    • pp.123-126
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    • 2002
  • Pollutants that are persistent, bioaccurnulative, and toxic have been linked to numerous adverse effects in human and animals, PBTs include heavy metals, polychlorinated biphenyls (PCBs), dioxins, polycyclic aromatic compounds (PACs) in addition to pesticides. This study focuses on toxic effects of the PBTs except pesticides on insects. Eight PBTs were selected from subgroups: three heavy metals (Pb, Hg, and Cd), two PCB mixtures (Aroclor mixtures 1 and 2), 2,3,7,8-tetrachlorodibenzo-p-dioxin, two monophenols (4-octylphenol and 4-nonylphenol), and tetrabutyltin, Beet armyworm, Spodoptera exigua, was used as test target insect species. Three physiological markers (metamorphosis, immune reaction, and follicle patency) were assessed in each exposure to different doses of the PCBs. Heat-shock proteins as molecular markers were also analyzed in response to the PCBs. All tested PBTs were toxic to metamorphosis from larvae to pupae when they were applied with diet. Two PCB mixtures were the most toxic compounds in this assay by giving significant toxicity at 0.005 ppm, while others had from 10 to 1000 ppm. Dioxin (0.1 ppb), tetrabutyltin (0.1 ppb), Pb (10 ppb), and Hg (0,01 ppb) were potent to inhibit immune reactions analyzed by inducing phenoloxidase activity and blocked phospholipase $A_2$ enzyme, Tetrabutyltin and dioxin significantly induced follicle cell patency, but their effects were lower than that of endogenous juvenile hormone, Dioxin, Pb, Hg, and Cd could induce the expression of heat shock proteins that were detected by immunoblotting against human HSP70 monoclonal antibody. HSP78 and HSP80 were upregulated in response to the PBTs. This expression was detected from the fat body and epidermis at as fast as 4h after injection. All these results clearly suggest that PBTs give significant ecotoxicity to insects that are valuable organisms in our environment.

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Cryopreservation of the Entomopathogenic Namatode, Steinernema carpocapsae Weiser (곤충병원선충(Steinernema carpocapsae Weiser)의 냉동저장법)

  • 이승화;김용균;한상찬
    • Korean journal of applied entomology
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    • v.39 no.3
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    • pp.149-152
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    • 2000
  • Cryopreservation of infective juveniles of entomopathogenic nematode, Steinernema carpocapsae Weiser, was conducted at $-190^{\circ}C$ liquid nitrogen and its, efficacy was analysed on nematode survival and pathogenicity with glycerol pretreatments and storage periods. Infective juveniles were pre-treated before being frozen by incubating the nematodes in 22% glycerol for each of 6, 12, and 24 h, followed by 70% methanol at $0^{\circ}C$ for 10 minutes. Just after glycerol and methanol incubations, subsamp1es of the nematodes were resuspended in 0.85% saline and maintained during 24h for viability determination. Different glycerol incubation periods significantly affected the nematode susceptibility to methanol infiltration. Six hour incubation in glycerol resulted in much less nematode survival than did 12 h or 24 h incubation. About 70% of the infective juveniles frozen at $-190^{\circ}C$ for 5 months, preincubat-ed in glycerol at least for 12h, were able to survive after being resuspended in 30°C saline. They did not also show any change in their pathogenicity during cryopreservation. These results suggest an improved technique for long-term storage of the entomopathogenic nematodes.

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Pathogenicity of Spodoptera exigua Nuclear Polyhedrosis Virus and Cross Infection of Baculoviruses to the Beet Armyworm, S. exigua (Lepidoptera: Noctuidae) (파밤나방 핵다각체병바이러스의 병원성과 곤충간상바이러스의 파밤나방에 대한 교차감염에 관한 연구)

  • 임대준;최귀문;강석권
    • Korean journal of applied entomology
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    • v.30 no.3
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    • pp.212-218
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    • 1991
  • Pathogenicity of Spodoptera exigua nuclear polyhedrosis virus (SeMNPV) against the host insect and 8 species of lepidopterous insects and cross infection of baculoviruses to third instar of S. exigua larvae were studied to determine as a biocontrol agent for S. exigua. The median lethal concentrations($LC_{50}$)of the SeMNPV to egg mass was $2.855\times10^5$ PIBs/ml and higher than that to the larvae of S. exigua. Mortality of the SeMNPV in third ins tar larvae was more increased than that in first and fifth instar of S. exigua larvae by 1.16 and 4.11 times, respectively. The median lethal times($LT_{50}$) to $1.56\times10^6$ PIBs/ml was in the range of 4.25 to 5.04 days. Infectivity of the SeMNPV against eight species of lepidopterous insects was showed only in the host insect, S. exigua. Autographa cali/ornica MNPV, Mamestra barassicae MNPV, and Trichoplusia ni MNPV were cross-infected to third instar of S. exigua larvae among ten of baculoviruses tested.

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Genetic Variation of Larval Stripe Patterns of Spodoptera exigua(Hubner) (파밤나방(Spodoptera exigua (H bner)) 유충 줄무늬 형질의 유전변이)

  • 김용균
    • Korean journal of applied entomology
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    • v.37 no.2
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    • pp.163-170
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    • 1998
  • Larval morphological characters such as body color and stripe pattern were analyzed to get morphological genetic markers of beet armyworm, Spodoptera exigua (Hiibner). Body color was varied from light green to dark brown with diets. Stripe characters were classified by the presence of dorsal and lateral lines: three stripes with both lines, one stripe with dorsal line only, and zero stripe. Proportions of each stripe character increased with successive selections for its own character. Three stripe was dominant to one stripe when they were crossed. The estimated heritability in narrow sense (h2) of the stripe pattern was 0.50k0.42. About two fold more females than males were produced in zero stripe line. Stripe pattern was not significantly changed by different diets except in welsh onion which had lower proportion of three stripe individuals than that of the expected. Larval stripe pattern was also correlated with larval and pupal developmental rates and cold hardiness but not with insecticide susceptibility.

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