• 한국미생물·생명공학회지
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• 제47권3호
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• pp.423-433
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• 2019

Midgut microbiota is known to play a fundamental role in the biology and physiology of the agricultural pest, Spodoptera litura. This study reports the difference in the larval midgut microbiota of field-caught and laboratory-reared populations of S. litura by performing 16S rDNA amplicon pyrosequencing. Field populations for the study were collected from castor crops, whereas laboratory-reared larvae were fed on a regular chickpea based diet. In total, 23 bacterial phylotypes were observed from both laboratory-reared and field-caught caterpillars. Fisher's exact test with Storey's FDR multiple test correction demonstrated that bacterial genus, Clostridium was significantly abundant (p < 0.05) in field-caught larvae of S. litura as compared to that in the laboratory-reared larvae. Similarly, bacterial genera, such as Bradyrhizobium, Burkholderia, and Fibrisoma were identified (p < 0.05) predominantly in the laboratory-reared population. The Bray-Curtis dissimilarity matrix depicted a value of 0.986, which exhibited the maximum deviation between the midgut microbiota of the laboratory-reared and field-caught populations. No significant yeast diversity was seen in the laboratory-reared caterpillars. However, two yeast strains, namely Candida rugosa and Cyberlindnera fabianii were identified by PCR amplification and molecular cloning of the internal transcribed space region in the field-caught caterpillars. These results emphasize the differential colonization of gut residents based on environmental factors and diet.

• International Journal of Industrial Entomology and Biomaterials
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• 제15권1호
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• pp.87-91
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• 2007

A diverse kind of environment-friendly agricultural materials(EFAM) for the control of insect pests is on the market. These EFAMs are a part of essential sources for the accomplishment of successful, sustainable, and environment-friendly agriculture. Thus, accurate information of these EFAMs is one that required for the success of environment-friendly agriculture, but, in reality, still appropriate information is absolutely in shortage. In this study, we, therefore, tested the efficacy of commercial EFAMs against two lepidopteran insect larvae, the diamondback moth Plutella xylostella(Lepidoptera: plutellidae) and the tobacco cutworm Spodoptera litura(Lepidoptera: Noctuidae). After the two insect pests were successfully stabilized in indoor environment the larvicidal activity was tested at $24{\pm}1^{\circ}C$, relative humidity(RH) of $60{\pm}5%$, and a photoperiod of 16L:8D, and mortality was determined 48 hrs after EFAMs are treated. The EFAMs that showed more than 90% of larvicidal activity were each six among 16 against both P. xylostella and S. litura and only three of them showed consistent larvicidal activity against both species, signifying species specificity of EFAMs and importance of selection of proper EFAMs depending on target insect pest.

• 한국응용곤충학회지
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• 제40권2호
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• pp.137-141
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• 2001

담배거세미나방 방제를 위한 핵다각체병 바이러스와 NeemAzal-T/S의 혼합처리 효과는 다음과 같다. 인공사료에 혼합 처리하여 실내 검정한 결과 핵다각체병 바이러스$ 1$\times$10^{8}$ PIBs/ml과 NeemAzal-T/S ppm 혼합한 경우에 $LT_{50}$ 과 $LT_{95}$가 각각 1.94일과 8.33일로 다른 처리구보다 빠르게 나타났다. 핵다각체병 바이러스 $1$\times$10^{6~8}$ PIBs/ml과 NeemAzal-T/S ppm 혼합살포로 단독처리보다 $LT_{95}$에서 3일 정도의 살충기간을 단축할 수 있었다. 배추유묘에서의 병원성 검정 결과 바이러스 단독처리는 4일째의 살충율이 10.7~6.7%로 낮으나, 핵다각체병 바이러스와 NeemAzal-T/S혼합 처리시에 살충효과가 빠르고 살충율도 높게 나타났다. 특히 핵다각체병 바이러스 $1$\times$10^{8}$ PIBs/m1과 NeemAzal-T/S 75~200 ppm처리에서는 9일째에 100%의 살충율을 보였다. 핵다각체병 바이러스를 처리하지 않은 담배거세미나방 유충은 초기 235mg에서 7일째에 2,194 mg으로 9.4배의 체중이 증가하였다. NeemAzal-T/S 단독처리시에는 200 pprn에서 1,120mg으로 4.8배 체중이 증가하였으며 바이러스 단독처리에서는 $1$\times$10^{8}$ PIBs/ml에서 7.0배 증가하였다. 그러나 두처리를 혼합하면 7일째에 $SINPV1$\times$10^{4~8}$ /+NeemAzal 75~200 ppm에서 3.9~2.9배만이 증가하여 단독처리보다 체중증가가 둔화되어 혼합처리에 의한 상승효과가 있었다.

• Fisheries and Aquatic Sciences
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• 제12권1호
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• pp.1-5
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• 2009

Crude saponin, extracted from the starfish Asterias amurensis, was assessed for its capacity as a biological pesticide. As part of this analysis, its insecticidal and repellent activities, in addition to its acute and chronic toxicities were tested. In comparison with the control group, insecticidal activity of saponin against tobacco cutworm, Spodoptera litura, in kale, Brassica loeracea was low at 36.4%. Repellent activities of the extracted saponin against green peach aphid, Myzus persicae, and S. litura, on soybean leaf, Glycine max and kale were 65.6% and 35.0% at $1^{st}$ day, and 54.5% and 30.0% at $3^{rd}$ day, respectively. Acute and chronic toxicity analysis was carried out using acute immobilizatioin test and reproduction impairment test, respectively. The saponin had 48 h-$EC_{50}$ of $65.21{\mu}g/mL$. Twenty-one day accumulative reproduction after treatment was lower in Daphnia magna at $7{\mu}g/mL$ saponin (78 youngs), compared with the control group (129 youngs). These results indicate that the extracted saponin exhibited some toxicity and has potential as a repellent against insects.

• 한국응용곤충학회지
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• 제57권4호
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• pp.347-354
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• 2018

드론을 이용한 배추 해충 방제기준을 설정하기 위하여, 드론의 살포높이(3, 4, 5 m), 진행속도(3, 4 m/sec) 에 따른 하향풍 속도, 살포 폭, 그리고 낙하 입자수와 입자크기를 감수지를 이용하여 조사하였고, 항공방제용 농약 4종을 이용하여 배추 주요해충인 배추좀나방, 파밤나방, 담배거세미나방에 대하여 완전치사농도와 약량을 실험실에서 검정하였다. 드론의 농약 살포시 면별 낙하입자비율은 표면 80.5, 수직면 14.8, 밑면 4.7%였고, 살포높이에 따른 낙하입자수는 3 m = 53, 4 m = 40, 5 m = 39개/$cm^2$였다. 비행속도별 낙하입자수는 3 m/sec = 62, 4 m/sec = 25개/$cm^2$였다. 실내시험에서 배추좀나방의 완전치사농도와 치사량이 클로르페나피르액상수화제(20배, $0.5{\mu}l$) 비스트리플루론 클로르페나피르 액상수화제(25배, $0.5{\mu}l$)였다. 파밤나방에 대하여는 클로르페나피르액상수화제(20배, $1{\mu}l$), 비스트리플루론 클로르페나피르액상수화제(20배, $1{\mu}l$)였고, 담배거세미나방에 대하여는 클로르페나피르액상수화제(20배, $1{\mu}l$), 비스트리플루론 클로르페나피르액상수화제(20배, $0.5{\mu}l$)였다. 따라서 드론을 이용하여 배추 주요해충을 방제하는 방법으로 클로르페나피르액상수화제 또는 비스트리플루론 크로르페나피르액상수화제를 20배액으로 희석하여 3 m 높이에서 3 m/sec 속도로 살포하면 72개/$cm^2$의 농약입자가 낙하하므로 해충방제에 효과적일 것으로 판단된다.