• Title/Summary/Keyword: INSECT

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Effects of the Insect Growth Regulator Dimilin on Larval Development of Hemigrapsus sanguineus (Crustacea, Brachyura) Reared in the Laboratory (무늬발게 幼生에 對한 Dimilin 의 致死 影響)

  • Kim, Chang Hyun
    • The Korean Journal of Ecology
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    • v.13 no.1
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    • pp.19-24
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    • 1990
  • The effects of insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the crab larvae of Hemigrapsus sanguineus. The larvae were cultured at control, 0.5, 1, 5 and 10 $\mu g$ Dimilin solutions and three replicate experiments were carried out to give correct analysis. Significant differences in percent mortality have occurred between control and 10$\mu g$ when the larvae were exposed to Dimilin whereas no differences were found between 5 and 10$\mu g$ Dimilin concentrations. If lethal concentration is defined as concentration at which less than 10 percent of crab larvae reach to the last zoeal stage from hatching it can be concluded that insect growth regulator Dimilin is lethal to the larvae of Hemigrapsus sanguineus at 5 and 10$\mu g$ Dimilin.

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Characterization of ORF39 from Helicoverpa armigera Single-nucleocapsid Nucleopolyhedrovirus, the Gene Containing RNA Recognition Motif

  • Xu, Hai-Jun;Liu, Yan-He;Yang, Zhang-Nv;Zhang, Chuan-Xi
    • BMB Reports
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    • v.39 no.3
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    • pp.263-269
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    • 2006
  • In the genome of Helicoverpa armigera single-nucleocapsid nucleopolyhedrovirus, open reading frame 39 (Ha39) is the only gene predicted to encode an RNA recognition protein. Computer analysis revealed that Ha39 homologues were found in 15 NPVs, but not in GVs. Its transcripts were detected from 3 through 72 hours post infection (h p.i.) using RT-PCR and Northern blot analysis. The protein was detected in infected-cell lysates from 6 h p.i. Western blot assay of ODV and BV preparations revealed that Ha39 encodes a structural protein associated with BVs. Additionally, immunofluorescence microscopy demonstrated that the protein was present within cytoplasm in virus-infected cells, but not in the nuclear region.

A study on the lift-generation mechanism of an insect with tandem wing configuration (두 쌍의 날개를 가지는 곤충의 양력 발생 메커니즘에 대한 연구)

  • Kweon, Ji-Hoon;Choi, Hae-Cheon;Chang, Jo-Won
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.389-394
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    • 2007
  • Numerical simulations are conducted to investigate the mechanism for force generation of an insect with tandem wing configuration. Various stroke amplitudes, stroke plane angles and phase difference between the fore- and hind-wings are considered. The Reynolds number is 150 based on the chord length and maximum translation velocity of the wing. When an insect requires high lift such as takeoff, it flaps its wings in parallel at a lower stroke plane angle and a bigger stroke amplitude than those in the hovering. With wings in counter-stroke, the lift fluctuations decrease, and moreover mean lift force decreases. Interactions among the fore-wing, hind-wing and vortices are examined to explain the force variations

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In vitro and in vivo Transient Expression in Insect Cells Mediated by the Cationic Liposome DDAB/DOPE

  • Xiao, Qing-Li;Zhou, Ya-Jing;Zhang, Zhi-Fang;He, Jia-Lu
    • International Journal of Industrial Entomology and Biomaterials
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    • v.4 no.1
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    • pp.57-62
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    • 2002
  • Cationic liposomes complexed with DNA have been extensively utilized for the delivery of reporter or therapeutic genes both in culture and in vivo. We investigated and determined the optimum conditions of a cationic liposome, composed of dimethyldioctadecy-lammonium bromide (DDAB) and dioleoyl phosphati-dylethanolamine UOPE), mediated a reporter plasmid expressing luciferase into insect cell lines (Sf-21 and Bm-N) and silkworm larvae. Together the data demonstrated that Bombyx mori nuclear polyhedrosis virus (BmNPV) genomic DNA (128 kb) was successfully transfected into Bm-5 cells using this liposome. These results suggest that DDAB/DOPE liposome will be useful as delivery agents for gene transfer to insect cells both in vitro and in vivo.

Insect Diapause (곤충의 휴면)

  • Go, Hyun-Jeong;Seong, Su-Il;Hwang, Jae-Sam
    • Journal of Sericultural and Entomological Science
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    • v.46 no.2
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    • pp.80-88
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    • 2004
  • Insect diapause is a delay in development evolved in response to regulatory recurring periods of adverse environmental condition. Diapause has evolved in most insect species to ensure survival under unfavorable environmental conditions and to syncronize of the growth rate of the population. It is not referable to immediately prevailing adverse environmental condition, and thus differs from a delay produced by currently adverse conditions such as low temperatures. This paper was mainly based on the study of Denlinger.

The Changes of Occurrence Patterns of Major Rice Insect Pests in Korea (한국에 있어서 수도해충 발생 변천에 관하여)

  • 장영덕
    • Korean journal of applied entomology
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    • v.31 no.1
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    • pp.69-78
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    • 1992
  • The extensive cultivation of new yielding varieties might give some distruption to the rice insect pest complex in Korea The population of Nephottetix cincticeps and Laodelphax striatellus has decreased in number since the extensive cultivation of new varieties, Tongil lines, in 1976. During the last 23 years, the rice insect pest population except for Chilo suppressalis drastically decreased, however, C. suppressalis population increased again in recent years. This tendency seems to be very closely correlated with the cultivation of new varieties, and a lot of fertilizations and insecticides applications.

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