The green peach aphid, Myzus persicae (Sulzer), is one of the most serious pest in cabbage cultivation. Field survey was carried out to know the insecticide resistance levels in five main cabbage cultivation regions (Pyeong-chang, Hong-cheon, Bong-wha, Mu-ju and Je-ju) in 2009. The green peach aphid can resist a wide range of insecticides in five surveyed local populations. Among the nine tested insecticides, four chemicals (methomyl, bifenthrin, pymetrozine and flonicarmid) showed less than 50% mortality in the recommended concentration in all populations. Multi resistant (MR) strain was selected from these populations and esterase over-expression, modified AChE (MACE) and mutation(s) in para-type sodium channel were analysed using native IEF and quantitative sequencing with five local populations. Esterase over-expression and MACE (StoF mutation) were observed in all populations including MR strain. LtoF mutation is well known as a kdr mutation in para-type sodium channel. However, even though LC50 values of MR strain noted over 2,000 times higher than that of susceptible strain against bifenthrin, any mutation was not detected in para type sodium channel and also local populations. These results suggested that unusual case could be existed in pyrethroid resistance mechanism in green peach aphid.

This study was conducted to improve the effect of environment-friendly Tetranychus urticae pesticide through the development of Tetranychus urticae biopesticide using the plant extract. Tested extracts were fig leaf extract, viburnum erosum extract; besides Sophora flavescens Ait extract, Derris root extract, Tobacco leaf extract, and they were proved to be the caricidal effect of two spotted spider mite adults by spraying on the French bean leaf inoculated for Tetranychus urticae with each concentration; 500ppm, 200ppm, 100ppm, 50ppm. In the control treatments, caricidal effect was compared with only ‘Eungsami’ (500ppm, 200ppm, 100ppm, 50ppm), of which the main ingredient as environment-friendly organic material is, and distilled water. The caricidal effect of tested extracts to the two spotted spider mite adult was the highest in the Sophora flavescens Ait extract and Tobacco leaf extract over 90%, and comparatively low in the Derris root extract. When the caricidal effect of ‘Eungsami’ was compared with two spotted spider mite adults with each concentration, ‘Eungsami’(500ppm) and Tobacco leaf extract(500ppm) were very excellent as each 95.5%, 98.7% in treated concentration. The effect of Sophora flavescens Ait extract was also high as 96.5%. In the low concentration(50ppm), Sophora flavescens Ait extract was 45.8%, Tobacco leaf extract was the most effective as 53.8%.

본(本) 실험(實驗)은 벼멸구에 대한 반수치사약량(半數致死藥量)의 차이(差異)를 나타내는 저항성(抵抗性) 및 감수성계통(感受性系統)과 그들의 교잡종(交雜種) 에 대(對)한 생화학적(生化學的) 특성(特性)을 구명(究明)하고자 실시(實施)하였다. 살충제무처리(殺蟲劑無處理)의 esterase활성(活性)은 저항성계통(抵抗性系統)과 교잡종(交雜種) 이 감수성계통(感受性系統)에 비(比)하여 높았으며, diazinon, MEP, BPMC 처리후(處理後) esterase의 활성변화(活性變化)는 저항성계통(抵抗性系統)과 교잡종(交雜種) 에서는 별차이(別差異)가 없었으나 감수성계통(感受性系統)에서는 현저(顯著)히 떨어졌다. Esterase의 높은 활성(活性)은 저항성발달(抵抗性發達)과 관계(關係)가 있었으며 교잡종(交雜種) 에서 esterase 활성(活性)이 높게 나타난 것은 저항성계통(抵抗性系統)이 우성인자(優性因子)로 유전(遺傳)됨을 알 수 있었다.