• Molecular & Cellular Toxicology
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• v.3 no.1
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• pp.68-75
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• 2007

[ $\alpha$ ]-Terpinene has been known as a repellent against the mosquito Culex pipiens pallens Coquillett based on a human forearm bioassay. $\alpha$-Terpinene showed significantly greater repellency than a commercial formulation, N, N-diethyl-m-methylbenzamide (deet). In this study, skin and eye sensitivity of $\alpha$-terpinene (2%) was examined with bioassays using white New Zealand rabbits. There were somewhat gross and histological changes observed in these treatments. Eye irritancy assays examined gross changes to cornea, iris and conjuctiva, and histological changes to smear of ocular discharge and eye tissue. Treated rabbits were divided into two cohorts, a saline washed cohort (W) or a non-washed cohort (NW). Opacity of cornea and redness, chemosis and discharge of conjuctiva were observed in both cohorts, but disappeared within 4 and 10 days in W and NW, respectively. Main components of ocular discharges were fibrin, epithelial or epitheloid cells, lymphoid cells, erythrocytes and granulocytes. These abnormal cellular components disappeared within 4 days and 10 days in W and NW, respectively. No permanent histological differences were observed between the two cohorts. However, severe irritation was determined as 57.2 of I.I.O.I value on the first day after treatment. These findings indicate a spray-type solution containing 2% $\alpha$-terpinene may serve as an alternative mosquito repellent and further studies need to reduce the eye irritation with formulation changes.

• Journal of Veterinary Clinics
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• v.29 no.1
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• pp.63-67
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• 2012

Mosquitoes are the vectors of a number of viral diseases in cattle, such as Akabane disease, bovine ephemeral fever, Ainovirus infection, Chuzan virus infection, and Ibaraki disease. These diseases are transmitted from an infected animal to a non-infected host via the blood feeding of the vector. In Korea, the National Veterinary Research and Quarantine Services, Ministry for Food, Agriculture, Forestry and Fisheries is responsible for planning, implementation, laboratory investigations and reporting the results of the national surveillance program for mosquito-borne bovine diseases (MBD). The surveillance program, which was started in 1993, focused to determine the seroprevalence of each disease in cattle herds in space and time. From the epidemiological point of view, more important component of the surveillance program is to monitor infection rates in vectors for specific pathogens because this information is essential for a more precise understanding the dynamics of these diseases in a given environment and for determining risk of transmission. The aim of this study was to describe and compare methods for estimation of vector infection rates using maximum likelihood (MLE) and minimum infection rate in pooled samples. Factors affecting MLE such as number of pools, pooling size and diagnostic test performance are also discussed, assuming some hypothetical sampling scenarios for MBD.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.494-504
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• 2016

Eucalyptus oils are widely used as spices, perfume industrial materials, food flavorings, and medicines. Several types of Eucalyptus oils also have insecticidal activity and as carminative. This study investigated the chemical composition, insecticidal (larvicidal and repellent) activity of E. urophylla oil against filarial mosquito Culex quinquefasciatus. E. urophylla oil was obtained from fresh leaves by water-steam distillation with oil yield 1.08%. E. urophylla oil in this study had no color (clear), has odor (typical eucalyptus), with specific gravity 0.941; refractive index 1.465; miscibility in 70% ethanol 1 : 3; and optical rotation (-) $5.83^{\circ}$. The major compounds of the oil were ${\alpha}$-pinene (11.73%), 1,8-cineole (49.86%), ${\beta}$-ocimene (6.25%), ${\gamma}$-terpinene (9.11%), and ${\alpha}$-terpinyl acetate (7.63%). The result showed the excellent insecticide activity against C. quinquefasciatus. The oil provided larvicidal activity with $LC_{50}$: 80.21 ppm and $LC_{90}$: 210.18 ppm, and repellent activity with $IC_{50}$: 0.82% and $IC_{90}$: 4.88%. The present study showed the effectiveness of E. urophylla as natural insecticide against C. quinquefasciatus, the mosquito vector of filariasis.

• Journal of Life Science
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• v.28 no.2
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• pp.195-200
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• 2018

Beta-asarone is the well-known active ingredient of Rhizoma acori graminei. In this study, we investigated and compared the binding affinity of mosquito oviposition pheromone (MOP; (5R,6S)-6-acetoxy-5-hexadecanolide) and beta-asarone on the A domain of the mosquito odorant binding protein 1 (CquiOBP1) by in silico computational docking studies. The three-dimensional crystallographic structure of CquiOBP1 was obtained from the PDB database (PDB ID: 3OGN). In silico computational auto-docking analysis was performed using PyRx, Autodock Vina, Discovery Studio Version 4.5, and the NX-QuickPharm option based on scoring functions. The beta-asarone showed optimum binding affinity (docking energy) with CquiOBP1 as -6.40 kcal/mol as compared to the MOP (-6.00 kcal/mol). Among the interacting amino acids (LEU76, LEU80, ALA88, MET89, HIS111, TRP114, and TYR122), tryptophan 114 in the CquiOBP1 active site significantly interacted with both MOP and beta-asarone. Amino acids substitution (mutation) from non-polar groups to the polar (or charged) groups of the CquiOBP1 dramatically changed the X, Y, Z grid position and binding affinity of both ligands. These results significantly indicated that beta-asarone could be a more potent ligand to the CquiOBP1 than MOP. Therefore, the extract of Rhizoma acori graminei or beta-asarone can be applied to the fields of insecticidal and repellant biomaterial development.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.181-188
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• 2016

BtPlus is a group of biopesticides that are made of Bacillus thuringiensis and immunosuppressant. A new BtPlus that exhibits high insecticidal activity against mosquito larvae has been investigated in control efficacy in field conditions and its environmental safety against aquatic system. This study assessed the control efficacy of BtPlus against mosquito larvae with two different application methods. In aerial spraying application (100 mL per $3.3m^2$), BtPlus was effective at 50% or above formulation concentrations to control mosquito larvae. For a direct application to aqueous mosquito habitat, a semi-field mimicking paddy rice field was constructed. In this condition, BtPlus showed 80% and 100% control efficacies at 0.1% and 0.2% concentrations, respectively. BtPlus also showed 40% mortality against adults at 0.1% concentration in 10% sugar bait. However, its control efficacies against adults were much less than against larvae. Safety assessment of BtPlus against ecosystem was evaluated using young carp (Cyprinus carpio), a water flea (Daphnia magna), and a honey bee (Apis mellifera). BtPlus did not give any adverse effects on these nontarget organisms. Based on these results, BtPlus can be applied to control mosquitoes by direct aqueous application to paddy rice field.

• Journal of the Korean Association of Geographic Information Studies
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• v.16 no.3
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• pp.12-24
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• 2013

Eradication of endemic malaria was declared in mid 1980's in Korea, but the number of malaria cases has been oscillating for the past 10 years since the reemergence of the disease in early 1990's. The occurrence of malaria has been concentrated near the demilitarized zone(DMZ), and the regional characteristics of the disease are evident. Considering the spatial variations of malaria incidence across the high-risk areas, the hotspot of the disease, it seems that the occurrence of the disease is influenced by the natural and human environment in the region. Malaria is an infectious disease that is transmitted to humans by the bites of vector-mosquitoes carrying malaria parasites, and it depends on specific climatic and sociodemographic factors. Malaria transmission is highly climate-sensitive, and temperature is the most important component. In addition, human contacts with vector-mosquitoes and the distance between human residence and mosquito habitats are crucial conditions determining malaria incidence rates. The present study aimed to test a hypothesis that the spatial characteristics of malaria incidence depended on local climatic conditions, relative proportions of mosquito habitats, and the distance between mosquito habitats and human residence using meteorological and satellite-based land cover data.

• Korean journal of applied entomology
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• v.44 no.3 s.140
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• pp.243-249
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• 2005

We investigated the repellency of eight mosquito repellents against Culex pipiens pallens and Aedes albopictus, and the quantity of DEETs were analysed by using gas chromatography. Ae. albopictus showed higher bloodsucking efficacy than Cx. pipiens pallens of the two subjects mouse and human hands, and human hand was more efficacious method for mosquito bloodsucking efficacy than mouse. Among the eight repellents were tested with mouse as subjects for eight hours, product C, G, and H were high repellency than others. In the case of human hands as subject, product C was highly effective than above other products. The DEET quantities of eight repellants varied from 7.31 g to 38.9 g in 100 g contents and we ascertained that there was a correlation between mosquito repellency and the DEET quantities remained after the treatments. It was evidenced from the long term test with shirt piece, in this test the Ae. albopictus attack was increased when the DEET quantity decreased below 40%.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.369-376
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• 2022

Five different methanol extracts of plants were evaluated as a mosquito repellent against Aedes albopictus in nude mice model. The volatile components of plants were analyzed with GC-MS. The effective dose was the highest in Nepeta cataria with 72.9, 83.7, 86.4, and 97.3% efficiencies at 10, 50, 100, and 200 ㎍/mL, respectively. Nepeta cataria, Actinidia polygama, and Artemisia annua extracts were the most effective in duration time test. And there was no difference compared to negative control in the low mosquito repellent efficiency from 30 minutes. As a result of analyzing the volatile components of each plant, a total of 28 components in Mentha suaveolens, 19 components in Actinidia polygama, 27 components in Artemisia annua, 26 components in Nepeta cataria, and 19 components in Taraxacum platycarpum were detected. Especially, nepetalactone known as an effective ingredient of a mosquito repellent was identified (27.95 mg/Kg) in one of volatile components of Nepeta cataria. Overall, our results provide the possibility to develop mosquito repellents material using natural plants which contain various volatile components.

• Korean journal of applied entomology
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• v.38 no.2
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• pp.165-169
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• 1999

A study was performed on the susceptibility of Abate@ and Abate-S@ against 3rd instar larvae of 5 species of mosquitoes including Anopheles sinensis, Aedes dorsalis, Culex inatomii, Cx. pipiens pallens, Cx. tritaeniorhynchus and mosquito larvivorous fishes such as Chinese muddy loaches (Misgurnus muzolepis) and crucian carps (Carassius carassi~4s) in September, 1998. Cx. pipiens larvae showed that the LC5os of both Abatea and Abate-Sa were 0.006 ppm. The LC95 values of this mosquito species appeared 0.070 pprn of Abate@ and 0.035 pprn of Abate-S@ which were more susceptible than the dosage (1.0 ppm) recommended from WHO. An. sinensis larvae appeared 0.009 pprn of LC50 and 0.025 pprn of LCgs. The larvae of Cx. inatomii and Ae. dorsalis showed the most highly susceptible to Abate-S@ among the 5 mosquito species with LC50 values of 1.9 x pprn and 1.1 x pprn respectively, and the LC95 values were 5.2 x 10-hppm and 1.4 x ppm, respectively. On the other hand, Cx. tritaeniorhynchus appeared least affected by Abate-Sa. and was brought 0.048 pprn of LC50 and 0.808 pprn of LCg5. These two insecticides were much less toxic to the fishes than mosquito larvae showing the LC, value of Chinese muddy loaches at 24.145 pprn of Abate and 10.750ppm of Abate-S@. This fish species showed that the LCsos of Abate@ and Abate-S@ were 27.567 pprn and 14.775 ppm, respectively. In case of crucian carps, their LC, values were 7.914 pprn of Abate@ and 6.480 pprn of Abate-S@. Therefore, the maximum safe dosages of the insecticides to the fishes were 8 times as high as the values of LCg5 of the mosquito larvae. This study suggests that Abate@ and Abate-S@ demonstrated highly potential insecticides for further larger scale operational integrated control in some proper aquatic places if other aquatic invertebrates are also safe to the insecticides.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2004.05a
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• pp.33-33
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• 2004