• Title/Summary/Keyword: Insect pests

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Effect of Essential Oils and Paraffin Oil on Black Cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae) (식물정유와 파라핀오일이 검거세미나방에 미치는 영향)

  • Lee, Dong Woon;Potter, D.A.
    • Weed & Turfgrass Science
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    • v.2 no.1
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    • pp.62-69
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    • 2013
  • The black cutworm, Agrotis ipsilon (Hufnagel), damages various cultivated crops and it can also be a serious pest of turfgrass, especially on golf courses. Essential oils have potential as alternative control agents for insect pests. Sixteen essential oils (anise, camphor, cinnamon, citronella, clove, fennel, geranium, lavender, lemongrass, linseed, neem, peppermint, pine, thyme, turpentine and tea saponin) and paraffin oil were assessed in the laboratory, the green house and field trials for their efficacy against black cutworms in turf. Treatment of potted cores of perennial ryegrass turf with anise, cinnamon, neem, paraffin or turpentine reduced black cutworm damage in a greenhouse trial, and in a similar trial, applying neem oil at 4000, 2000 and 1000 ppm resulted in 100, 100 and 64% mortality, respectively, of black cutworms. Weight of survivors at the 1000 ppm rate was 5- fold less than weight of comparably-aged controls. Neem oil (2000 ppm) reduced growth of black cutworms feeding on treated clippings. A high rate of neem oil followed by irrigation (0.1 L of 20000 ppm neem oil with 0.9 L watering/$m^2$) was more effective than a lower concentration (1 L of 2000 ppm neem oil/$m^2$) against $2^{nd}$ and $3^{rd}$ instars in potted turf cores and field plots, respectively. However, not even the aforementioned higher rate effectively controlled $4^{th}$ instars in the field.

Effect of a Low Temperature-Induced Quiescence on Short Term Storage of an Egg Parasitoid, Trichogramma sp. Nabis 101 (알기생봉(Trichogramma sp. Nabis101)의 저온 발육 휴지와 단기 저장 기술)

  • Kim, Yong-Gyun;Heo, Hye-Jung;Kim, Geun-Seob;Hahm, Eun-Hye;Kim, Ji-Won;Kang, Sung-Young;Kwon, Ki-Myeon
    • Korean journal of applied entomology
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    • v.48 no.3
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    • pp.369-375
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    • 2009
  • A commercial egg parasitoid, Trichogramma sp. Nabis101, was released into agricultural cultivating areas in Korea due to its wide host spectrum against insect pests. Moreover, an application technique has been recently developed to enhance its control efficacy by mixture treatment with a microbial control agent. Despite its expansion of commercial availability, any genetic identification on this commercial strain was not determined. Also, to meet inconsistent demands from consumers, the live parasitoids need to be stored without significant loss of their survival and parasitic activity. This study determined nucleotide sequence of internal transcribed spacer (ITS) of the wasp species. The identified ITS sequences indicate that this wasp species is most similar to T brasiliensis. Optimal storage condition of this wasp required young parasitized stage at $10^{\circ}C$. Under these conditions, survival, sex ratio, longevity, and parasitic behavior were not much impaired for 5 weeks.

Influence of Pre-treated Eco-friendly Agricultural Materials on Control Efficacy of Isaria javanica Isolate against Sweet Potato Whitefly (Bemisia tabaci) (친환경 농자재와 곤충병원성 곰팡이 Isaria javanica의 처리 간격이 담배가루이(Bemisia tabaci) 방제에 미치는 영향)

  • Lee, Byung-Ju;Han, Ji-Hee;Huang, Jeong-Hwa;Kim, Jeong-Jun;Lee, Sang-Yeob
    • Korean Journal of Organic Agriculture
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    • v.25 no.3
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    • pp.631-642
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    • 2017
  • For effective control of insect pest which can outbreak in a field during crop cultivation, various control agents such as eco-friendly agricultural materials (EFAM) including microbial control agents and chemical pesticides have been applied at fields and these control agents may be treated simultaneous or sequential in the same field to suppress diverse pests and diseases. The agents may influence each other and control efficacy may also differ from interactions. Therefore we need to test compatibility of microbial control agents with other agricultural agents. In this study, we investigated influence of pre-treated EFAMs, which are registered for whitefly control in greenhouse, on germination, mycelial growth and control efficacy of Isaria javanica isolate against sweet potato whitefly. The results showed that a mixture of paraffin oil+cinnamon oil among 4 EFAMs highly reduced germination ($8.9{\pm}1.3%{\sim}24.5{\pm}0.9%$) and mycelial growth ($0.81{\pm}0.01cm{\sim}0cm$) of I. javanica. To investigate the effects of the treatment interval between EFAMs and I. javanica on sweet potato whitefly control, four different EFAMs were pre-treated 0, 1, 4, and 7 days before applying I. javanica. Pre-treatment of four EFAMs inhibited insecticidal activity of I. javanica against sweet potato whitefly. Therefore when EFAMs and a mycopesticide using I. javanica spray simultaneous or sequential, application of EFAMs need more than 7 days interval after treatment of mycopesticide at field.

Comparison of Metabolic Pathways of Less Orthologous Prokaryotes than Mycoplasma genitalium (Mycoplasma genitalium 보다 보존적 유전자 수가 작은 원핵생물들의 대사경로 비교)

  • Lee, Dong-Geun
    • Journal of Life Science
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    • v.28 no.3
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    • pp.369-375
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    • 2018
  • Mycoplasma genitalium has 367 conserved genes and the smallest genome among mono-culturable prokaryotes. Conservative metabolic pathways were examined among M. genitalium and 14 prokaryotes, one hyperthermophilic exosymbiotic archaeon Nanoarchaeum equitans and 13 intracellular eubacteria of plants or insects, with fewer conserved genes than M. genitalium. They have 11 to 71 metabolic pathways, however complete metabolic pathways ranged from 1 to 24. Totally, metabolic pathway hole is very high due to the lack of 45.8% of the enzymes required for the whole metabolic pathways and it could be suggested that the shared metabolic pathway with the host's enzyme would work or the essential substances are host dependent. The number of genes necessary for mass transfer through the cell membrane is also very low, and it may be considered that the simple diffusion or the protein of the host will function in the cell membrane of these prokaryotes. Although the tRNA charging pathway was distributed in all 15 prokaryotes, each has 5-20 tRNA charging genes. This study would give clues to the understanding of the metabolic pathways of intracellular parasitic bacteria of plant and endosymbiotic bacteria of insects, and could provide basic data for prevention of crop damage, development of insect pests and human medicines.

Identification and characterization of the phytocystatin family from Brassica rapa

  • Hong, Joon-Ki;Hwang, Jung-Eun;Park, Tae-Ho;Zang, Yun-Xiang;Lee, Sang-Choon;Kwon, Soo-Jin;Mun, Jeong-Hwan;Kim, Hyun-Uk;Kim, Jin-A;Jin, Mi-Na;Kim, Jung-Sun;Lee, Soo-In;Lim, Myung-Ho
    • Journal of Plant Biotechnology
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    • v.35 no.4
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    • pp.317-327
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    • 2008
  • Phytocystatins, which are inhibitors of plant cysteine peptidases, are involved in the regulation of protein turnover and in the defense against insect pests and pathogens. Extensive searches in the Brassica rapa genome allowed the prediction of at least eight different phytocystatin genes on seven chromosomes in the B. rapa genome. Structure comparisons based on alignments of the all BrCYS ($\underline{B}$. $\underline{r}apa$ $phyto{\underline{cys}}tatin$) proteins using the CLUSTALW program revealed conservation of the three consensus motifs known to interact with the active site of cysteine peptidases. According to the phylogenetic analysis based on the deduced amino acid sequences, the eight BrCYS proteins were divided into several clusters related to the orthologous phytocystatin. The predicted three-dimensional structure models of the eight BrCYS proteins demonstrate that all of these proteins are similar to the reported crystal structure of oryzacystatin-I (OC-I). Digital northern and RT-PCR analyses indicated that the eight BrCYS genes exhibit different expression patterns in B. rapa tissues and respond differently to abiotic stimuli. The differences in gene structure and expression between the eight BrCYS genes suggest that these proteins may play diverse physiological roles in B. rapa and may interact with cysteine peptidases through different mechanisms.

Changes in Chemical Property of Soil Affected by Termites (Reticulitermes speratus kyushuensis Morimoto) in Korea (국내 흰개미(Reticulitermes speratus kyushuensis Morimoto)에 의한 토양의 화학적 특성 변화)

  • Seong, Se Ha;Kim, Keun Ki;Hong, Chang Oh;Park, Hyean Cheal
    • Journal of Environmental Science International
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    • v.26 no.6
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    • pp.789-795
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    • 2017
  • Termites (Isoptera) are classified into approximately 3,106 species. In Korea, only one species has been identified, which is Reticulitermes speratus kyushuensis Morimoto. The termite, a social insect, is known to play an important role in nutrient cycling of the ecosystem, although some species of termites are well-known pests attacking wooden structures or any plant materials. However, there is a lack of research about termites in Korea, including aspects such the taxonomy, physiology, and ecology of termites. This study was carried out to provide valuable basic data on the ecological role of termites in an ecosystem in Korea for the future studies. For the experiments, soil and termite samples were randomly collected from Mt. Hwajang located in Jikdong-ri, Eonyang-eup, Ulju-gun, Korea between October 5 and 30, 2015. Analysis results showed that there were no significant differences in soil chemical properties between the soil samples just after air-drying and one year elapsed without any treatment. The treated soil with termites showed significantly higher than the soil without termite treatment. Chemical properties of total nitrogen, organic matter, available phosphate, pH, Calcium(Ca), Potassium(K) and Magnesium(Mg) in soil treated with termites were $1.11{\pm}0.3gkg^{-1}$, $43.3{\pm}12.4gkg^{-1}$, $27.4{\pm}2.9mgkg^{-1}$, $4.56{\pm}0.2$, $0.82{\pm}0.2cmol_ckg^{-1}$, $3.18{\pm}1.4cmol_ckg^{-1}$, $1.73{\pm}1.1cmol_ckg^{-1}$, respectively. The values of soil property of without termite treatment were $0.56{\pm}0.1gkg^{-1}$, $30.5{\pm}3.1gkg^{-1}$, $24.0{\pm}4.7 mgkg^{-1}$, $4.09{\pm}0.1$, $0.71{\pm}0.2cmol_ckg^{-1}$, $2.88{\pm}1.5cmol_ckg^{-1}$, $1.30{\pm}0.7cmol_ckg^{-1}$, respectively. These results suggest that inhabitation of termites could improve soil chemical properties in an ecosystem.

Development of a New Disinfestation Method Using Methyl Bromide and PH3 in Cut Rose Fumigation (절화장미 훈증처리시 Methyl Bromide와 PH3를 이용한 새로운 살충방법의 개발)

  • Son, Ki-Cheol;Byoun, Hye-Jin;Kim, Mi-Kyoung;Yun, Jae-Gil;Kim, Eui- Young
    • Horticultural Science & Technology
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    • v.16 no.3
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    • pp.370-373
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    • 1998
  • Fumigation by combination of methyl bromide/phosphide ($MB/PH_3$) was much more effective in disinfestating the rose insect pests (Aphis gossypii, Tetranychus urticae, and Frankliniella occidentalis) than that by individual MB or $PH_3$. Fumigation for 2 hours in the chamber using ;$MB/PH_3$ at the concentration of $10/3g{\cdot}m^{-3}$ brought about 91.3% and 100% mortality in aphids and thrips, respectively. Fumigation for 3 hrs using ;$MB/PH_3$ at the concentration of 5/3 or $7/3g{\cdot}m^{-3}$ showed over 96% mortalities in mites and thrips as well as no phytotoxicity symptoms, e.g. tip burn or bent neck, in cut roses, while mortalities of mites and thrips were not influenced by increasing $CO_2$ concerntration from 0.03% to 10% or decreasing $O_2$ concentration up to 15% in fumigation chamber.

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Characteristics of Spatiotemporal Patterns in Benthic Macroinvertebrate Communities in Two Adjacent Headwater Streams (두 인접한 산림 하천에서 저서성 대형무척추동물 군집의 시공간적 특성 분석)

  • Lee, Da-Yeong;Bae, Mi-Jung;Kwon, Yong-Su;Park, Chan-Woo;Yang, Hee Moon;Shin, Yujin;Kwon, Tae-Sung;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.51 no.2
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    • pp.192-203
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    • 2018
  • Headwater streams provide various microhabitats, resulting in high diversity of macroinvertebrate community. In this study, we compared the differences of communities between two adjacent headwater streams (Jangjeon stream (GRJ; GRJ1-GRJ5) and Haanmi stream (GRH; GRH1-GRH3)) in Jungwang and Gariwang mountains, Gangwon-do and evaluated the effects of habitat condition to the macroinvertebrates community composition. In order to characterize the macroinvertebrate communities and extract influential environmental factors, we applied to Cluster analysis (CA), Indicator species analysis and Non-metric multidimensional scaling (NMDS). Total 33,613 individuals in 3 phyla, 5 classes, 13 orders, 51 families, and 114 taxa (genera or species) were collected. Gammarus sp. was dominant at the upper stream of GRJ, whereas Chironomidae spp. was abundant at GRH and the downstream of GRJ. The CA classified samples into six clusters (1-6) reflecting spatial and temporal variation of benthic macroinvertebrate communities. Benthic macroinvertebrate community composition was significantly different between two adjacent streams. Sweltsa sp. 1, Psilotreta kisoensis, Rhyacophila shikotsuensis and Serratella setigera were identified as representative indicator species for clusters 1, 2, 3 and 5, respectively. Similar to CA results, NMDS revealed the spatial and temporal differences of benthic macroinvertebrate communities, indicating the difference of community composition as well as microhabitat condition. Forest composition, proportion of boulders (>256 mm), and water velocity were main factors affecting the macroinvertebrate community composition.

Chemical Characterization and Insecticidal Activity of Rubus coreanus Miquel Extracts (Leaves, Fruits and Stems) against Three Agricultural Insect Pests, Myzus persicae, Plutella xylostella and Spodoptera litura (특용작물:복분자의 화학적 특성 및 복분자 부위별 (잎, 열매, 줄기) 추출물을 이용한 농업해충 복숭아혹진딧물, 배추좀나방 및 담배거세미나방에 대한 살충효과 연구)

  • Lee, Hee-Kwon;Lee, Hoi-Seon
    • Korean Journal of Organic Agriculture
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    • v.24 no.4
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    • pp.849-857
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    • 2016
  • In the growth of the Rubus coreanus Miquel fruits, the unripened (10 days) and ripened (25 days) fruits after flowering were harvested. The chemical characteristics of different maturational stages of the unripened and ripened fruits were investigated. Total amount of phenolic compounds was 4.00-7.56% in the unripened fruits and 3.78-5.57% in the ripened fruits, respectively. Furthermore, total amounts of organic acids such as malic, citric, succinic, and oxalic acids were 16.40 mg/100 g in the unripened fruits and 28.82 mg/100 g in the ripened fruits, respectively. In organic acids of the unripened and the ripened fruits, citric acid (8.76-15.47 mg/100 g) was the highest amount among other organic acids. Soluble sugars were significantly increased from 11.07 to 21.54% in the unripened and ripened fruits. Therefore, ripened fruits had the high levels of phenolic compounds, organic acids and soluble sugars. For the biological studies of R. coreanus, methanol extracts of R. coreanus leaves, fruits, and stems were evaluated for their insecticidal activities against Myzus persicae (Hemiptera: Aphididae), Plutella xylostella (Lepioptera: Plutellidae) and Spodoptera litura (Lepioptera: Noctuidae) by leaf dipping method. From these results, the extract of R. coreanus leaves revealed potent insecticidal activity against P. xylostella. However, the methanol extracts of R. coreanus fruits and stems had no any insecticidal activity against M. persicae, P. xylostella and S. litura. The R. coreanus leaves have promising potential as new insecticidal agent against P. xylostella.

Comparison of Anatomical Characteristics for Wood Damaged by Oak Wilt and Sound Wood from Quercus mongolica (참나무시들음병 신갈나무 피해목과 건전목의 해부학적 특징 비교)

  • JEON, Woo-Seok;LEE, Hyun-Mi;PARK, Ji-Hyun
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.6
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    • pp.807-819
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    • 2020
  • The aim of this study was to investigate the anatomical characteristics of Quercus mongolica infested by oak wilt disease. To analysis the anatomical characteristics of the wood specimens infested by the oak wilt, the anatomical structures of an infected wood, a dead wood, and sound wood were observed at 10-year-old intervals from 10 to 50 annual rings using both an optical and a scanning electron microscope. The fiber length was measured in units of 5 annual rings from the pith, and the diameter of the vessel element and the ratio of the vessel including the tyloses were measured for each 10 annual ring. In the cross section, on the infected and dead wood specimens, mycelium was also observed with the tyloses in the vessel. There was no signification difference between the wood specimens in the fiber length and the vessel diameter of the vessel element. The fiber length was not difference after 20-30 annual rings which is a part of juvenile wood. The average of the vessel ratio including tyloses in the infected wood was the highest. Especially, the ratio of tyloses was the highest 40-50 annual rings in the infected wood and the dead wood. Therefore, the large difference between the infested wood by oak wilt and the sound wood was the ratio of tyloses. This result can be used as a basic data to utilize the infested wood.