The cotton aphid, Aphis gossypii glover (Hemiptera: Aphididae), is the world-wide agriculture pest and has the ability to become resistant to many pesticides. Hence, we conducted behavioral tests on apterous and alate aphids for series compounds from natural products by using a two-choice test, a no-choice test, a host choice test and electroantennography (EAG). As a result, we found 3 out of 30 compounds for apterous aphids and 2 out of 15 compounds for alate aphids, both of which showed powerful repellent effects on these aphids. In this study, we suggest that our findings could be useful and eco-friendly spatial repellents for controlling cotton aphid.

친수성 및 소수성 나노실리카를 tetraethyl orthosilicate(TEOS)를 커플링제로 사용하여 유리 표면에 거친 스파이크 구조 형성과 반응성 hydroxyl기를 동시에 도입한 후 불소를 함유한 실란으로 2차 코팅처리하여 궁극적으로 발수성 유리 표면 형성의 최적 조건을 확립하는 연구를 수행하였다. 소수 성 나노실리카인 실리카 에어로졸을 이용한 초소수 도막의 형성은 나노실리카 표면에 반응성인 -OH기가 존재하지 않아 내구성이 있는 소수성 도막을 형성할 수 없었다. 이에 반하여 친수성기를 가진 나노 실리카와 가수분해된 TEOS를 포함하는 코팅액 이용하여 유리 표면을 1차 코팅한 후 2차로 trichloro-(1H,1H,2H,2H)perfluorooctylsilane(TPFOS) 용액으로 코팅하여 150o 이상의 수접촉각을 가지는 초소수 표면을 제조하였으며, 1o 이하의 물 슬라이딩각을 보여 초발수성도 동시에 가지고 있었다. 이에 덧붙여 친수성 나노실리카의 함량이 증가할수록 광투과도가 감소하였으며, TPFOS 용액에 의해서도 광투과도가 감소하였다. 코팅된 유리시편의 내구성 50회 문지름까지는 초소수성을 유지하였으나, 200회 문지름에서는 단지 소수성만을 유지하였다. 결론적으로 최적의 코팅액의 조건은 친수성 나노실리카의 함량이 0.3 g인 HP3 코팅액을 2회 코팅한 후 2차로 TPFOS 용액으로 코팅하는 것이었다. 이렇게 제조된 코팅액은 광투과도가 중요한 솔라셀의 표면 처리제로 사용이 가능할 것으로 판단된다.

Glass wool is widely used as a typical soundproofing material because it has superior characteristics as a soundproofing material as well as excellent marketability. However, moisture penetration through condensation and cleaning up causes deterioration of insulation and soundproofing performance. In this study, we evaluate the wettability and sound absorption performance when the metal is deposited on the surface of glass wool. The performance is examined based on parameters such as the angle test, drying speed, the absorbency, the moisture content, the wettability. The wettability data shows that Cu coated glass wool is the best performance compaed to Ti coated one. The sound insulation characteristics are also compared by using the impedance tube. At the low frequency range, there is no difference among the test specimens, however, at the frequency above the 250 Hz range, Cu coating shows 10 % better in th sound asorption. Ti coating has almost same to the existing glasss wool performance. It turns out that metal coating on the glass wool seems to be very promising: the metal deposition reveals strong water repellency and sound absorption performance is equivalent to the existing glass wool.

Glass wool is a fiber made by melting sand and waste glass at high temperature. It has been used as an inorganic fiber for sound absorption, insulation, and non-combustible materials for automobiles, ships, and household appliances. However, the disadvantage comes from the moisture penetration through condensation and cleaning up so that it deteriorates insulation and soundproofing performance. In order to overcome the disadvantages of glass wool, we investigate the water repellency by plating metal on the surface of glass wool with Cu and Ti while coating stability is considered. The thickness of the deposited metal is about 300 nm. The deposition chemicals and the image of the specimen are analyzed by using SEM equipment. The electron microscopic result shows that quite amount of Cu and Ti metals are deposited on the glass wool surface.

Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) is an important pest in protected culture. We assessed fourrepellents (carvacrol, cis-jasmone, methyl jasmonate, and methyl salicylate) of Frankliniella occidentalis (Pergande)(Thysanoptera: Thripidae) known from literatures to develop a behavioral management tactic against F. intonsa. We measuredthe repellency of F. intonsa that exposed to 100 times diluted repellents on leaf disc. Repellency was 2.60 times higherin methyl jasmonate followed by methyl salicylate (2.16 times), cis-jasmone (2.15 times) and carvacrol (2.08 times) comparedto control. These results suggest that methyl jasmonate can be incorporated as a component of integrated managementof F. intonsa.

The potato tuber moth, Phthorimaea operculella (Zeller), is a ubiquitous pest on potatoes, tobacco, tomato and othercrops. The small hive beetle (SHB), Aethina tumida Murray, is a pest of European honeybees (Apis mellifera L.) in severalcountries in the world. Propolis is a balm-like substance collected from plants by bees. Its chemical composition variesand depends mainly on the flora in the region in which it is collected as well as the bee species. Hitherto biologicalproperties and the chemical composition of the essential oil extracted from propolis of Korean origin are unknown. Inthis study, while searching for an environmentally friendly method to control these pests we evaluated the repellent effectsof essential oil of propolis collected from Bee Lab of Andong National University and found that it possess repellentactivity against both small hive beetle and potato tuber moth. Moreover, a total of 171 constituents of the oil were identifiedof which 6 were major compounds using GC/MS analysis. We also compared the chemical composition of this oil withthose from 2 Ethiopian regions.

Haemaphysalis longicornis is a major vector for Severe fever with thrombocytopenia syndrome (SFTS) throughout Republic of Korea (ROK). The ticks distribute at vast open fields and various kind of habitate. Control of the ticks with pesticides is almost impossible and personal protection such as use of commercial repellents is very critical for control. However occasional toxic effects of the commercial repellents have been reported that include central nervous system depression and urticaria. In our studies, repellency of three plant essential oils was assessed and was compared with two commercial repellents. Lavendual angustifolia demonstrated the highest repellency and higher repellency than DEET when was individually tested, but binary mixture of Cinnamomum zeylinicam and Juniperus verginiana showed significantly higher repellency with synergic effects than mixture of Lavendula angustifolia and Juniperus verginiana. Further study on repellency of the C. zelinicam in field need.

Previous laboratory repellent assessment with three plant essential oils against Haemaphysalis longicornis, a major vector for Severe fever with thrombocytopenia syndrome, revealed high repellency of Lavendual angustifolia and high synergic effects of Cinnamomum zeylinicam and Juniperus verginiana. Based on the previous laboratory repellent assessment field studies on repellency of the three plant oils were carried out with formulations such as cream type and spray type. 10% spray type of Cinnamomum zeylinicam demonstrated > 70% of repellency against H. longicornis. 10% spray type of Lavendual angustifolia showed > 80% of repellency. 10% spray type of binary mixture containing Cinnnamomum zeylinicam and Juniperus verginiana showed > 98% repellency against H. longicornis. Further studies on repellency of cream type of the plant oils might be carried out and compared with two commercial repellents.

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.

Repellency of 20 plant essential oils to malaria main vector in the Republic of Korea (ROK), Anopheles kleini, was evaluated using skin direct contact bioassay. Anopheles kleini showed the highest repellency to Pelargonium graveolens with EC50 value of 0.244 mg/cm2, followed by Pinus sylvestris and Cinnamomum camphora with EC50 values of 0.484 mg/cm2 and 0.862 mg/cm2. The lowest repellency of An. kleini was revealed from Clary sage oil with EC50 value of 4.665 mg/cm2. Anopheles kleini did not demonstrated any repellency to Lemon, Orange, Neem, Coconut and Olive oil over 20 mg/cm2. Major repellent constituents of Geranium, Pine and Camphora oil were analyzed and identified using Mass-data, GC and GC-Mass. Major constituent of Geranium were β-citronellol (37.0%) and Camphora, 1,8-cineole (35.8%) and Pine, α-terpineol (39.5%). Anopheles kleini showed higher repellency to β-citronellol and 1,8-cineole than to DEET and IR3535 and did not showed any repellency to sabinene and γ-eudesmol over 20 mg/cm2. Residual repellent time of 1,8-cineole and β-citronellol were 26 and 41 min, respectively and DEET, 84 min and IR3535, 102 min. In the light of global efforts to reduce the level of highly toxic synthetic repellents, the three essential oils and their major constituents described merit further study as potential biorepellents for the control of An. kleini populations

The repellency, insecticidal activity and repellency duration effect of dagalet thyme, Thymus quinquescostatus against Asian tiger mosquito, Aedes albopictus larvae and adults was investigated. Whole plant body of T. quinquescostatus proved to have the repellent activity of 91.2% against A. albopictus adults. The constituents of T. quinquescostatus were analyzed using GC-MS as follows: α -pinene (1.1%), α-thujene (2.7%), camphene (1.3%), myrcene (4.7%), α-terpinene (5.0%), ɤ-terpinene (33.0%), ρ-cymene (8.3%), β-caryophyllene (4.0%), β-bisabolene (8.9%), thymol (29.9%), and carvacrol (1.2%). Among them, thymol has the perfect repellency on A. albopictus adults and confirmed the electrophysiological response on the antenna of A. albopictus adults. To enhance the maintenance, vanillin was added. Duration of effectiveness of mixture with vanillin (0.18 : 0.36 ㎕/㎠) were significantly more prolonged than thymol alone. The constituents on its original oils were applied onto A. albopictus larvae. The thymol, α-terpinene and carvacrol (LC50 = 9 mg litre-1) revealed to have high insecticidal activity.

The repellency of 104 plant essential oils to female Aedes aegypti was examined using a cage-distribution assay. Results were compared with those of the conventional mosquito repellent N,N-diethyl-m-toluamide (DEET). Coriander, oreganum, pennyroyal, lemoneucalyptus, and spearmint exhibited high repellency effect (>60 minutes at 50 mg/filter paper), followed by sage, leavander, tarragon, bergamot, and neroli oils which showed moderate effective (< 40 minutes at 50 mg/filter paper (5 cm diameter)). In the light of global efforts to reduce the level of highly toxic synthetic repellents, essential oils described merit further study as potential repellents for the control of mosquito populations.