Toxicities of 10 insecticides were examined against late third instars of Culex tritaeniorhynchus using the direct-contact mortality bioassay. Six geospatially distant field mosquitoes were collected from Chuncheon-si (designated CC-CT), Hwaseong (HS-CT), Seosan (SS-CT) Jeonju (JJ-CT), Daegu (DG-CT), and Busan (BS-CT) in the Republic of Korea (ROK). Marked regional variations of insecticide susceptibility were observed. Field populations of SS-CT, JJ-CT and DG-CT from agricultural areas showed higher to extremely higher insecticide susceptibility to pyrethroids than those of CC-CT, HS-CT and BS-CT strains from none agricultural areas. Extremely high to low levels of susceptibility were measured: bifenthrin, susceptible ratio (SR) = 2.7–896.3; β-cyfluthrin, SR = 1.8–633.3; α-cypermethrin, SR = 1.2–1,051.9; deltamethrin, SR = 1.3–711.1; permethrin, SR = 1.5–1,053.4 etofenprox, SR = 2.2–29.3; chlorfenapyr, SR = 5.1–103.6; chlorpyrifos, SR = 2.3–337.0; fenitrothion, SR = 2.0–142.3 and fenthion, SR = 1.4–186.2. Culex tritaeniorhynchus populations from rice paddies had been under heavy selection pressure due to the agricultural insecticides and that’s why the mosquito species demonstrated high resistance to pyrethroids which were used for a long time to control agricultural pests in the localities. These results indicate that careful selection and rotational use of these insecticides mayresult in continued satisfactory control against field populations of Japanese encephalitis vector mosquitoes.

Density of malaria vector mosquito was monitored at 24 sites in Korea to estimate malaria epidemic from 2004 to 2009. Twenty four locations include six in Gwangwon province and nine in Kyonggi province and nine in Incheon metropolitan city. Mosquitoes collected by public health centers in 24 sites were sent to each RIPHE(Research Institute of Public Health & Environment) then the RIPHE identified the malaria vector mosquitoes. KCDC analysed the results. Number of malaria vector mosquito collected in 2009 shapely decreased over 33 % when compared with number of mosquito collected from 2004 to 2009. In 2009, malaria vector mosquitoes firstly were collected at Injegun on 2nd week of April (6-13, April) and the highest peak of collected mosquito was demonstrated on 3rd week of August. Number of collected mosquito sharply decreased below 10 at 3rd week of september and None of mosquito was collected 2nd week October. Decrease of number of malaria vector mosquito collected in 2009 seem to be related with lowest temperature around midnight and precipitation days per month.

진흥(振興)과 유신(維新)을 공시(供試)하여 이앙시기(移秧時期), 재식밀도(栽植密度), 질소시비(窒素施肥) 수준(水準)과 벼잎집무늬마름병(病) 발생(發生)과의 관계(關係)를 검토(檢討) 하였다. 잎집무늬마름병(病) 발생(發生)은 5월(月) 26일(日) 이앙구(移秧區)보다 5월(月) 16일(日) 이앙구(移秧區)에서, 당 100주(株) 재식구(栽植區)가 80주(株) 재식구(栽植區)보다 , 질소질배비구(室素質倍肥區)(진흥(振興) 220kg/ha, 유신(維新) 300kg/ha) 가 보비구(普肥區)에서보다 발병(發病)이 심(甚)하였다. 또한 생육기간중(生育期間中) 발병(發病)이 심(甚)했던 재배조건(栽培條件)에서 성숙기(成熟期)의 피해도(被害度)가 높았다

The objectives of this study were to identify QTLs for agronomic traits using introgression lines from a cross between a japonica weedy rice and a Tongil-type rice. A total of 75 introgression lines developed in the Tongil-type rice were characterized. A total of 368 introgressed segments including 285 homozygous and 83 heterozygous loci were detected on 12 chromosomes based on the genotypes of 136 SSR markers. Each of 75 introgression lines contained 0-9 homozygous and 0-8 heterozygous introgressed segments with an average of 5.8 segments per line. A total of 31 quantitative and 2 qualitative loci were identified for 14 agronomic traits and each QTL explained 4.1% to 76.6% of the phenotypic variance. Some QTLs were clustered in a few chromosomal regions. A first cluster was located near RM315 and RM472 on chromosome 1 with QTLs for 1,000 grain weight, culm length, grain width and thickness. Another cluster was detected with four QTLs for 1,000 grain weight, grain length, grain width and grain length/width ratio near the SSR marker RM249 on chromosome 5. Among the 31 QTLs, 9 (28.1%) Hapcheonaengmi3 alleles were beneficial in the Milyang23 background. ILs would be useful to confirm QTLs putatively detected in a primary mapping population for complex traits and serve as a starting point for map-based cloning of the QTLs. Additional backcrosses are being made to purify nearly isogenic lines (NILs) harboring a few favorable Hapcheonaengmi3 alleles in Milyang23 background.