국내 천적농업이 활성화되기 위해서 토착천적을 개발하여야 한다. 토착천적들을 개발하기 위하여 시설재배 지 내에 다양한 비작물성 식물들을 확보하는 것이 필요하다. 식물의 종류가 많으면 이에 서식하는 기주곤충이 늘어나고 그 곤충들의 토착천적들이 증가한다. 이러한 시설재배지내에 식물 종다양성 확보를 위하여 재배작물 사이의 공간에 경합되지 않는 곳에는 다양한 잡초를 증식하거나 새로운 천적유지 식물을 개발하여 다양한 기주 곤충을 증식시켜야 한다. 현재 가장 많이 사용하는 것으로서 보리를 이용한 콜레마니진딧벌 천적유지식물이 개발되었지만, 그 외에도 담배, 천사의나팔 김장배추, 쑥, 소리쟁이, 냉이 등 다양한 천적유지식물들을 개발할 수 있다. 즉, 토착천적을 개발하기 위하여 생태적으로 안정된 작물재배환경을 유지하는게 필요하고 이러한 안정 된 생태계 속에서 효과적인 천적을 통한 해충방제가 이루어질 수 있다.

최근 이상기후로 인한 총채벌레 발생 증가와 Neonicotinoids계, Pyrethroids계, Spinosyns계, Avermectins계 약제의 과다 살포, 중복 살포로 인한 저항성 발달로 총채벌레 방제가 어려운 상황이다. 본 연구에서는 총채벌레의 약제저항성 관리 및 효율적인 방제전략을 세우기 위한 기초 연구로 곤충성장저해제(insect growth regulator, IGR)의 적용 가능성을 검토하였다. 꽃노랑총채벌레 알, 1령 약충, 2령 약충, 성충으로 나누어 시험 약제를 처리하고, 조사는 약충의 경우 168시간까지 생충수, 알과 성충은 144시간까지 생충수와 부화 약충수를 조사하였다. 조사결과 클로르플루아주론 유제는 1령 약충, 2령 약충에 대하여 접종 168시간 후 각각 100%, 80%의 방제효과를 나타내었다. 또한 시험약제를 성충에 처리 시 산란에 대한 영향도 확인할 수 있었다. 본 연구결과를 통해 곤충성장저해제의 꽃노랑총채벌레 령기별 적용 가능성을 확인할 수 있었으며, 총채벌레 적용약제의 계통을 다양화하여 저항성 관리에도 도움이 될 수 있다고 판단된다.

The environmental friendly control of Platypus koryoensis (Murayama), a vector of oak wilt disease, was investigated using citral. To develop an effective attracted trap was performed in Yeoju (semi-field), Gunpo (field) and Cheongju (field). Using a ratio of four attractant (ethanol 100%, ethanol+citral (90:10, 95:5), ethanol+citral+hexane extract of Quercus mongolica (90:5:5)) was investigated attractive effects for the Platypus koryoensis. Most P. koryoensis were attracted to mixture of ethanol+citral (95:5). As a result, when using a citral in a certain concentration is would be able to develop an effective and environmental friendly control agent.

A variety of methods for detecting the location of an underground water pipeline are being used across the world; the current main methods used in South Korea, however, have the problems of low precision and efficiency and the limitations in actual application. On this, this study developed locator capable of detecting the location of a water pipe by the use of an IMU sensor, and technology for using the extended karman filter to correct error in location detection and to plot the location on the coordinate system. This study carried out a tract test and a road test as basic experiments to measure the performance of the developed technology and equipment. As a result of the straight line, circular and ellipse track tests, the 1750 IMU sensor showed the average error of 0.08-0.11%; and thus it was found that the developed locator can detect a location precisely. As a result of the 859.6-m road test, it was found that the error was 0.31 m in case the moving rate of the sensor was 0.3-0.6 m/s; and thus it was judged that the equipment developed by this study can be applied to long-distance water pipes of over 1 km sufficiently. It is planned to evaluate its field applicability in the future through an actual pipe network pilot test, and it is expected that locator capable of detecting the location of a water pipe more precisely will be developed through research for the enhancement of accuracy in the algorithm of location detection.

In Korea, six mealybug species have been reported on pears. This study investigated the occurrence of mealybugs in 19 pear orchards from 2013 to 2014. Two species, Crisicoccus matsumotoi (Siraiwa) (Hemiptera: Pseudococcidae) and Pseudococcus comstocki (Kuwana) were mainly found. The dominant species was C. matsumotoi identified on 73% of infested fruit. Toxicities of 14 registered insecticides (7 single formulations and 7 mixed formulations) commonly used to control P. comstocki were evaluated to C. matsumotoi nymphs and adults at the recommended concentration. As a results, all insecticides exhibited strong insecticidal activity with 100% mortality of both nymphs and adults. These results indicate that the 14 insecticides can be used in control for C. matsumotoi in field.

The larvicidal activities and repellency of Magnolia kobus extract against C. pipiens and Ae. albopictus were examined. M. Kobus methanol extraction showed 100% larvicidal activity both two mosquitoes at 500 ppm after treated 24 h. At a concentration of 50 ppm, the hexane fraction showed 100% and 94% mortality against C. pipiens and Ae. albopictus at 24 h, respectively. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel open column chromatography and HPLC. H2 fraction gave >90% mortality to both mosquitoes at 10 ppm after treated 48 h. H21 fraction was determined 100% larvicidal activity to C. pipiens at 10 ppm. However, very low larvicidal activity was obseved to Ae. albopictus. This is considered a synergistic effect between substances. It also appears that there is a susceptibility difference of substance against mosquito species. H21 fraction was analyzed as the lignan, sesamin (C20H18O6) by GC-MS and NMR. Mosquito repellent and olfactory response was using a patch test.

The repellent activities of 33 plant extracts against Aedes albopictus were examined using a patch test for adult. The six plant extracts (Magnolia denudate, Dryopteris crassirhizoma, Cnidium officinale, Lindera obtusiloba, Magnolia kobus, and Houttuynia cordata) showed over 70% repellency activities to Ae. albopictus. The insecticidal activity of Curcuma longa against Ae. albopictus was also determined. C. longa hexane extraction showed 100% larvicidal activity at 1,000 ppm after treated 24 h. Purification of the biologically active constituents from the hexane extraction with larvicidal activity was done using silica gel column chromatography. H1 fraction gave 100% mortality to Ae. albopictus at 100 ppm. H12 fraction was determined 87.8% larvicidal activity to Ae. albopictus at 50 ppm. Active constituent was analysed as the sesquiterpene, ar-turmerone (C15H20O) by GC and GC-MS. C. longa extract gave highly protection against mosquito bites. The hexane extraction showed complete protection at 10 mg over 6 h. In this study, the sesquiterpene from C. longa induced a protection time, repellency, landing time, and biting time against Ae. albopictus. These results suggest that the some plant extracts and C. longa have the potential to be used an eco-friendly materials for the control of mosquitoes.

An experimental study was carried out to evaluate the punching shear performance of H-steel column + RC slab system for vertical load. Three specimens were constructed for interior column-slab system. All specimens were the same configuration and material properties except for columns such as RC column+flat plate slab and H-Steel column+flat plate slab. From the test results structural characteristics (maximum proof stress, maximum displacement, deformation capabilities and so on) are obtained and evaluated.

From the methanol crude extracts of the tree of heaven (Ailanthus altissima) leaves, the antifeedant substance was isolated and bioassayed with different concentrations against diamondback moth (Plutella xylostella) larvae. The antifeeding activity was evaluated by measuring the feeding area during 24 hr after inoculation. Methanol extracts showing antifeeding activity at 5000 ppm was subsequently fractionated into hexane, chloroform, ethyl acetate and water layer. Third larvae of diamondback moth was tested to each fraction layer. Chloroform layer shows the highest antifeeding activity and the layer was purified by silica gel open column chromatography. The C22 and C23 fractions showed higher antifeeding ratio with 96 and 86%, respectively, and then these two fractions were re-isolated by ODS open column chromatography. As a result, both fractions in methanol 40% (v/v) showed antifeeding ratio over 90%. The C221 fraction showed insecticidal activity in all fraction, however, C231 fraction was showed the antifeeding activity only in C2311 fraction. The C2311 fraction judging to have antifeeding activity was re-isolated and purified by HPLC and recycling, and finally obtained the bioactive substances (C23111) with antifeeding ratio with 88%. The structure of bioactive materials isolated was confirmed by LC-mass and 1H-NMR(500 MHz), 13C-NMR(100 MHz).

This study was performed to investigate the antifeeding activity of Perilla frutescens extracts against diamondback moth, Plutella xylostella larvae and to confirm the electrophysiological responses of two sensilla (LST=lateral styloconic sensillum, MST=medial styloconic sensillum) in maxilla galea, a chemoreceptor. Crude extract of P. frutescens in methanol was showed antifeeding activity approximately 70%, and subsequently separated into four fractions - n-hexane(H), chloroform(C), ethylacetate(E), and water(W). Antifeeding activity was only showed in n-Hexane fraction around 99%. H1, H2, H3, H4, H5 were isolated from n-Hexane fraction using an open column chromatography, and the bioassay showed strongest antifeeding activity in H1 fraction. Using an oscilloscope, electrophysiological responses of two sensilla showed more seven times activity in MST. H11, H12, H13, H14 were separated from H1 fraction and antifeeding activity was showed highest in H11 fraction. H11 fraction was examined electrophysiological responses at doses of 100, 10, and 1 ppm, and MST of P. xylostella responded at a dose of 100 ppm. H11 fraction was separated using HPLC and identified using GC/MS and NMR. Finally, the structure of active compound proved to be farnesene with molecular weight of 204, and a formula of C15H24

This study was performed to investigate attraction effect of six plant essential oils and to confirm their electrophysiological response against Lycorma delicatula. Among the tested oils, spearmint oil (94.1%) significantly attracted L. delicatula at a dose of 1.25㎕/cm2 by using an olfactometer. In dose response to spearmint oil, a dose of 2.5㎕/cm2 was very effective. GC-MS analysis revealed that the active components responsible for the effective attraction effect of spearmint oil were carvone (70.6%) and limonene (54.8%). Of the two active components, carvone was more significant than limonene with reference to attraction activity against L. delicatula. Analysis by GC-EAD showed, major components of spearmint oil that elicited response in L. delicatula antennae, indicating the potential role of the essential oil as attractant that determine the choice of the attraction material. In the field test, spearmint oil exhibited attraction effect up to 5 days. This effect was different in accordance with test places and treatment dose.

Global warming means not only increase in average air temperature but also increase in frequency of extreme weathers such as extremely high temperature over 45oC. Crops are generally sensitive to high temperature during their reproductive growth stage. This experiment was thus conducted to investgate physiological responses of rice (Oryza sativa cv. Chucheong) and soybean (Glycine max cv. Sinpaldal) to high temperature (HT) stress at their reproductive stage. Rice and soybean were exposed to different degrees of high temperature stress by keeping them in a growth cabinet deisnged to maintain air temperature up to 45oC for at least 5 hours in a day for different durations, 0, 1, 2, 3, and 4 days. HT stress treatment delayed heading and flowering of rice and increased the sterility of its' main panicle with increasing duration of HT treatment; 19.7 43.4, 68.1, 81.5 and 91.1% at 0, 1, 2, 3 and 4 days HT treatment, respectively. Increasing sterility due to HT treatment thus resulted in significant rice yield loss; 5.07 4.27, 4.32, 4.51 and 3.62 g/plant at 0, 1, 2, 3 and 4 days of HT treatment, respectively. Soybean was also significantly affected by HT stress in its pod formation and sterility, particularly along the vertical stem. Increasing pod sterility with increasing HT treatemnt thus resulted in significant soybean yield loss.