• Korean Journal of Environmental Biology
• /
• v.39 no.3
• /
• pp.362-373
• /
• 2021

This study was conducted to establish mosquito distribution density and habitat in Sejong city for the prevention of mosquito-borne infectious diseases. The overall distribution of mosquitoes in the Sejong City was investigated, and the population density of mosquitoes in the old and new city was analyzed. Mosquito populations were determined using MOSHOLE and Blacklight traps once a week overnight. We also compared the mosquito population density of the old city and the new city, and the daily mosquito population was calculated using the data from the smart mosquito trap(DMS). Of all the study sites, Geumnam-myeon had the highest number of mosquitoes captured, and the dominant species were Armigeres subalbatus and Culex pipienspallens. Mosquito species with the potential for transmitting diseases were mainly found in Yeonseo-myeon (106 individual), and Geumnam-myeon (101). Mosquito collection rates by MOSHOLE trap and Blacklight trap were 58.49% and 41.51%, respectively. We concluded that using CO₂ would be the most suitable approach for collecting mosquitoes. The mosquito population density in the old city (92.05±7.04) was approximately twice that of the new city(51.50±4.05). Since Sejong City is divided into old city and new city, it is difficult to spot remarkable effects in a standardized way. For effective quarantine, differentiation of quarantine must be established. This study results provide a basis for Sejong City's integrated mosquito control guidelines, and therefore effective control of which we believe will help control the spread of mosquito-borne diseases and reduce damage from mosquitoes.

• Korean journal of applied entomology
• /
• v.45 no.3 s.144
• /
• pp.357-362
• /
• 2006

Bacillus thuringiensis strains were isolated from the domestic soil and a strain was selected that had a new host range and high toxicity against agriculture insect pest. The 142 samples of soil were sampled from the mountains, paddy fields and patches, in Daejon, Chungnam, Chungbuk and Jeonbuk and used for the investigation. Sixteen B. t strains were isolated from 12 samples among collected samples. There were 11 strains that showed toxical activity on Plutella xylostella (Lepidoptera: Yponomeutidae), 7 steins on Spodoptera litura (Lepidoptera: Noctuidae), 5 strains on Arete coerulea (Lepidoptera: Noctuidae), 5 strains on Culex pipiens pallens (Diptera: Culicidae) among the 16 isolated B. t strains. But there were not any strains that showed activity against Hyphanria cunea (Lepidoptera: Arctiidae) and Sitophilus oryzae (Coleoptera: Rhynchophoridae). And also some of B. thuringiensis strains showed insecticidal activity with 2, 3 or 4 kinds of insects. But there were also 3 strains that did not show any activities to the 6 insects which were used in the experiment. When examined with a phase-contrast microscope, the insecticidal crystal protein produced from 16 selected strains had 13 bipyramidal and 3 spherical shapes. The insecticidal bioactivity of the S. litura showed 100% mortality when there were $1.3{\times}10^{7}\;(cfu/ml)$ of CAB109 isolates.

• The Korean Journal of Pesticide Science
• /
• v.2 no.1
• /
• pp.91-96
• /
• 1998

For the expression of the cry11Aa gene highly toxic to dipteran insects, we constructed two cyanobacteria-Escherichia coli(E. coli) shuttle vectors, pCYASK5-l and pCYASK5-2. These vectors were transformed into E. coli and selected with kanamycin. The expression of the cry11Aa gene in E. coli was characterized by SDS-polyacrylamide gel electrophoresis and Western blot analysis. Two E. coli transformants harboring pCYASK5-1 and pCYASK5-2 expressed the cry11Aa gene in size of 72 kDa and 64 kDa, respectively and showed over 89% mortality against Culex pipiens larvae.

• The Korean Journal of Zoology
• /
• v.3 no.1
• /
• pp.9-12
• /
• 1960

The present status of insecticide resistance of Korean mosquitoes is still unknown. The experiment cited below is a part of our series of resistance tests on Korean mosquitoes. The test was carried out during the summer of 1959 to ascertain the degree of resistance of Culex pipiens to insecticides currently used. Culex pipiens eggs were collected from ditches in Seoul City and reared in laboratory with media consisted of the following : Distrilled water 1.0 liter, Magnesium sulfate (MgSO$_4$.7$H_2O$) 1.0gram , Calcium sulfate (CasO$_4$.2$H_2O$) 0.5gram ; Sodium cholride 0.5 gram. A Sufficient amount of beer yeast was also used as a larvar food. Late third and early fourth instar larvae were selected for testing. The results are summarized in the following. THe LC-50 of Culex pipiens to insecticides were 0.061 ppm in p, p-DDT , 0.045 ppm in ${\gamma}$-BHC and0.029 ppm in malathion. Comparing these with LC-50 doses of Orlando laboratory strain, it can be pointed out that the present resistance of Seoul strain shows about a ten-fold increase in DDt, and a fourfold increase in ${\gamma}$-BHC . The resistance development of the Seoul strain has, however, not arisen so markedly as compared with data observed in other parts of Far Eastern areas received heavy insecticidal operations.

• The Korean Journal of Zoology
• /
• v.21 no.2
• /
• pp.59-66
• /
• 1978

A dispersal experiment on Culex tritaeniorhynchus females by a mark-release-recapture method was carried out at Pohgang city, Korea, in Augst 1974. The results are summarized as follows: 1. Of 23,115 females of C. tritaeniorhynchus released, 120 females were recaptured, giving 0.519% recapture rate and 0.00208 recovery ration. 2. Dispersal rates from the release site were 77.5% in 0-2km, 11.7% in 4-6 km and 5.8% in 6-8km. 3. C. tritaeniorhynchus females flew 7.5km in one day. The average of the daily mean distances was 1.55km, and it showed that the dispersal distance did not correlate with days after release.

• The Korean Journal of Pesticide Science
• /
• v.2 no.1
• /
• pp.18-23
• /
• 1998

In order to obtain leading compound for the development of new pesticide through the organic synthesis of natural products, the synthesis of ricinine, an active compound of Ricinus communis, was established and biological activities of synthetic compounds against insects were examined. The synthetic scheme of ricinine was composed of four steps by the spontaneous condensation of the cyanoacetyl chloride. A modified synthetic process was also estabilshed to enhance the synthetic yield by simple cyclization of ethoxymethylene malononitrile. In the bioassay results of synthetic ricinine and intermediates on four insects, the mortality of ricinine on brown planthopper (BPH, Nilaparvata lugens) and pea weevil(PW, Bruchus rufimanus) was 80% and 75% at the concentration of 1,000 ${\mu}g/ml$ respectively. Chloronorricinine and chlororicinic acid having chloride group in molecular structure gave 60% mortality on two-spotted mite (TSSM, Tetranychus urticae) at the concentration of 500 ${\mu}g/ml$. The mortality of compounds on house mosquito (HM, Culex pipens pallens) was meager at 10 ${\mu}g/ml$ level.

• Korean Journal of Agricultural Science
• /
• v.41 no.3
• /
• pp.177-185
• /
• 2014

Aspiring to the new raw materials of insecticides is one of the plant extracts. The material structure of a variety of plant extracts have because the material to the defense of the plant itself, the case of insecticides, using plant extracts, safe, has low toxicity and has the advantage of highly distinctive and fall. Coltsfoot (Tussilago farfara L.) is belonging to the family Compositae, and distributed in all parts of China as medicinal plants and indigenous plants used. Coltsfoot is known that it is effect to respiratory disease and has an antiviral effect. However, the reported insecticidal activity of coltsfoot could be not found. Fortunately, I found insecticidal activities when I was screening the bioassay against several insects with a lot of plant extracts. Using the ethanol extract of the Tussilago farfara, there were insecticidal activities against Culex pipiens pallens and Tetranychus urticae. There were several fractions in ethanol extract of coltsfoot by using various organic solvents. Hexane fraction showed a higher insecticidal activity than any other fraction. It is confirmed that hexane fraction contained pyrethrin by using HPLC analysis. So, it might be suggested that extract of coltsfoot has an insecticidal activity and its effect due to a ingredient of pyrethrin.