본 연구에서는, 5가지 식물의 메탄올 추출물을 이용하여 모기기피 효과 실험을 진행하고 누드 쥐를 모델로 하여 흰줄숲모기에 대한 모기기 피제의 유효용량 및 유효시간을 평가하였다. 그리고 식물의 휘발성분을 GC-MS로 분석하였다. 유효용량은 개박하가 10, 50, 100, 200 μg/mL 에서 72.9, 83.7, 86.4, 97.3%의 효율로 가장 높았다. 누드 쥐를 대상으로 한 유효시간 연구에서는 5가지 식물의 메탄올 추출물 중 개박하, 개다 래 및 개똥쑥이 90.5%로, 30분까지만 지속하였다. 각 식물의 휘발성분을 분석한 결과, 애플민트 28개 성분, 개다래 19개 성분, 개똥쑥 27개 성분, 개박하 26개 성분, 민들레 19개 성분이 확인 되었다. 특히 모기기피제의 유효 성분으로 알려진 네페탈락톤(nepetalactone)이 개박하의 휘발성분 중 한 성분으로 확인 되었다(27.95 mg/Kg). 본 연구결과는 다양한 휘발성분을 함유한 식물을 이용한 모기기피제 재료로서 가능성을 제시한다.

Miticidal and repellent activity of twenty plant essential oils against the adults of two spotted spider mites, Tetranychus urticae, were examined. Sandalwood oil was the most potent one in mortality, whereas clary sage oil exhibited the greatest repellent activity. On those twenty essential oils tested, no apparent correlation between toxicity and repellency was observed. The chemical compositions of sandalwood and clary sage oils were identified via GC/MS analyses. The major constituents of sandalwood oils were sesquiterpene compounds, whereas the major ones for clary sage oil were monoterpenes. Among the major components in clary sage oil, linalyl acetate was not only the most abundant constituent, but also the most responsible one for its repellent activity against the adults of the two spotted spider mites. Nevertheless, the combination of seven major constituents of clary sage oil showed lesser repellent activity than the original essential oil did, implying the presence of interactions between the major and minor constituents affecting the overall repellent activity of the crude oil.

톱다리개미허리노린재는 최근 농약사용 횟수의 증가로 천적이 사라지면서 전국적으로 크게 발생을 하고 있다. 톱다리개미허리노린재는 년 2~3회 발생하며 포장 잔재물이나 포장 주위의 잡초 등에서 성충으로 월동한 후 다음 해 봄 기주작물인 콩과 작물, 과수작물, 곡류작물에 피해를 주는데 이중 콩이 가장 적합한 먹이원이며 피해가 가장 크다. 콩의 열매 성숙 초기 즉 착협기에 일어나는 톱다리개미허리노린재에 의한 섭식 피해가 수확량에 직접적인 영향을 주기 때문이다. 본 실험은 톱다리개미허리노린재에 대한 기피제 개발 목적으로 미나리과 식물체정유인 아조완 정유와 그 성분들의 톱다리개머허리노린재 성충 및 약충에 대한 기피 활성을 실험실내에서 four-arms olfactometer를 이용하여 조사하였다. 아조완 정유를 1.25 mg의 농도에서 처리했을 때 성충 수컷 89% 및 암컷 성충 90%가 기피를 보였다. 4령 약충의 경우, 성충과 같은 농도로 처리했을 때 73%의 기피 활성이 나타났다. 아조완 정유의 기피 활성 물질을 확인하기 위해 GC-MS로 정유를 분석하였고 12종의 정유 성분을 확인하였다. 12종의 아조완 정유성분들 중 각 성충 수컷과 암컷, 4령 약충에서 1 mg 농도로 처리했을 때 thymol과 carvacrol이 100%의 강한 기피 활성을 보였다. 아조완 정유와 정유성분들은 톱다리개미허리노린재의 집합페로몬 트랩과 같이 “push and pull”전략에 활용이 가능할 것으로 판단된다.

본 연구에서는, 20종의 식물정유를 이용하여 점박이응애 성충에 대한 살비활성 및 기피활성을 확인하였다. 살비활성 평가에서는 샌달우드 오일이, 기피활성 평가에서는 클라리 세이지 오일이 가장 높은 효과를 나타내었고, 평가에 사용한 20종의 식물정유간에는 살비활성과 기피활성간 의 상관관계가 매우 낮게 나타났다. 높은 활성을 나타낸 정유들의 혼합시험에서는, 거의 대부분의 조합이 서로간에 저해효과를 갖는 것으로 확인되었다. 샌달우드 및 클라리 세이지 오일의 구성성분은 GC/MS 분석을 통해 확인하였으며, 샌달우드는 세스퀴터펜류가, 클라리 세이지 오일은 모노 터펜류가 주종을 이루었다. 클라리세이지 오일의 구성성분 중에서는 linalyl acetate가 가장 높은 함량을 갖고 있을 뿐만 아니라, 해당정유가 기피효과를 갖는 주된 효능물질임을 확인하였다.

We evaluated the repellent activity of 12 Apiaceae plant essential oils and their components against male and female adult German cockroaches, Blattella germanica, to find new natural repellents. Of the plant essential oils tested, ajowan (Trachyspermum ammi) and dill (Anethum graveolens) essential oils showed the most potent repellent activity against male and female adult German cockroaches. Of the compounds identified, carvacrol, thymol, and R-(-)-carvone showed >80% repellent activity against male and female adult German cockroaches at 0.2 mg/L air concentration. S-(+)-Carvone, (+)-dihydrocarvone, and terpinen-4-ol showed >70% repellent activity against male and female adult German cockroaches at 0.8 mg/L air concentration. Our results indicated that Apiaceae plant essential oils and their constituent have good potential as natural repellents against adult German cockroaches.

The larvicidal and repellent activities of 33 plant extracts against two mosquitoes as Culex pipiens and Aedes albopictus were examined using direct contact application for larva and a patch test for adult. Chrysanthemum zawadskii var. alpinum, Cnidium officinale, Ginkgo biloba, Magnolia kobus, and Magnolia denudate at 1,000 ppm caused 100% mortality to Cx. pipiens larva within 24 hr. Ailanthus altissima, Dryopteris crassirhizoma, Houttuynia cordata, Mentha arvensis, Phyllostachys nigra, and Parthenocissus tricuspidata showed over 90% mortality to Cx. pipiens. C. zawadskii var. alpinum, C. officinale, G. biloba, M. kobus, M. denudate, and P. nigra gave 100% mortality at 1,000 ppm to Ae. albopictus. Acorus gramineus, Campanula takesimana, and D. crassirhizoma, showed 97.8%, 94.5%, and 94.4% mortality to Ae. albopictus at 24 hr, respectively. Five plant extracts (C. zawadskii var. alpinum, C. officinale, G. biloba, M. kobus, and M. denudate) showed 100% mortality both Cx. pipiens and Ae. albopictus. However, A. altissima gave 90% larvicidal activity to Cx. pipiens, whereas 7.8% mortality to Ae. albopictus. Several plant extracts which have highly larvicidal activities, were determined repellency against two mosquitoes species.

Six plant essential oils, vanillin, and their mixtures were tested for repellent activities and olfactory responses in a dengue virus vector mosquito, Aedes aegypti. Among the plant essential oils, cassia oil showed complete protection time (CPT) of 75 minutes. CPTs of lemongrass, lemoneucalyptus, xanthoxylum oils, and vanillin were within 30 minutes at 5% (0.21 mg/cm2) tested level, although their CPTs were not comparable to same concentration of DEET that showed 127.5 minutes of CPT. However, their repellency effects were significantly improved in two conditions; improving concentration up to 15% level (0.63 mg/cm2) and addition of vanillin. In bioassays using binary or tertiary mixtures with one or two essential oils with or without vanillin, the composition of 1:3:1 (v/v/w) consisted of lemongrass oil, xanthoxylum oil and vanillin provided 270 min-CPT. As a practical application, the mixture of 1:1:1 formulation containing lemongrass oil, xanthoxylum oil, and vanillin (v/v/w) was enclosed into the Viscopearl, porous cellulose beads that provide gradual release of volatile compounds. Efficiently, more than 90% of repellency for 2 hours was observed in cage and semi-field chamber tests using the formulation. In addition to behavioral assays, we subsequently examined how mosquitoes sense the blends of oils with vanillin by using electroantennogram (EAG) recording. Binary mixture with one oil and vanillin, which extended CPTs, showed no significant patterns of EAG alternation, while tertiary mixtures of oils and vanillin decreased patterns of EAG responses as an increase of vanillin contents in the mixture, implying further potential roles of vanillin as a synergist in mosquito repellency. Based on behavioral and electrophysiological data, cassia, rosemary, lemongrass, xanthoxylum, and lemoneucalyptus oils could provide the high possibility for development of commercial products for useful management strategies to control mosquitoes.

Aedes aegypti is a primary vector that transmits dengue and yellow fever around the world. To prevent the spreading and elimination of mosquitoes, insecticides and repellents like DEET (N, N-diethyl-m-methyl benzamide) have been broadly used. Even though DEET is considered as highly effective and proven protection against mosquito, it causes skin irritants and rashes, melts some synthetic plastics, and unpleasant smells. Therefore, there is a trend finding alternative mosquito repellents instead of using DEET. We tested repellent effects with plant essential oils and synergistic effects of those plant essential oils with additional vanillin, comparing them to DEET itself. Some of prepared mixtures showed better repellency than DEET. In addition, we evaluated the differences in the peripheral olfactory responses of Ae.aegypti females using EAG tests (electroantennogram). The aim of this test is to determined how the vanillin within plant essential oils or DEET acts in mosquito’s olfactory organs in aspect of molecular mechanisms. Revealing the novel function and localization of these putative repellent receptors may provide new insight into development of repellent as well as behavioral control agents in the future and contribute to understand the mechanism of processing patterns of repellent receptors in mosquitoes.

Methanol extracts of 35 plant species in 20 families were tested for their insecticidal activities and repellent effects against Nilaparvata lugens female adult by topical application and spray methods. The insecticidal activities and repellent effects of various plant species and parts were different. The methanol extracts from stem of Garcinia xanthochymus, Senecio scandens and Phytolacca americana, seedcoat of Ginkgo biloba, and leaf + stem of Ailanthus altissima and Catalpa ovata showed potent insecticidal activities against N. lugens. Specially, the G. biloba extract exhibited higher than 90% mortality against N. lugens at a concentration of 4,000 ppm. Repellent effects of plant extracts obtained from whole plant of Daucus carota, fruit of Semecarpus anacardium, leaf + stem of C. ovata and Wisteria sinensis were active, and potent. Also, the plant extracts that are potent in insecticidal activity not necessarily have high repellent activity showing no significant corelation between the two activities.

We evaluated two herbal plants, basil (Ocimum basilicum) and lemon balm (Melissa officinalis), for their potential as repellent plants in the management of striped flea beetle (Phyllotreta striolata), in organic production of chinese cabbage. It was confirmed that striped flea beetle avoided these two herbal plants in olfactometer experiment. We conducted field experiment in which the suppressive effect of the two selected herbal plants and cruciferous crops preferred by striped flea beetle were evaluated through cultivating as inter crops and border crops, respectively. In inter-cropping experiment, unlike in vitro test, the density of striped flea beetle was low in basil- or mustard-intercropping cultivation plot, but high in lemon balm-intercropping cultivation plot. In border cropping experiment, the density of striped flea beetle on chinese cabbage in lemon balm or basil cultivation plot were approximately zero. As a result of this study, we think that border cropping of lemon balm or basil can be used to reduce preventively