This experiment was conducted to find out the simultaneous control effect of granulated insecticides on the several major rice insect pests in Korea. The granulated insecticides used were Terracur P$5\%$ (one of the phosphoric insecticides), Lebaycid $5\%$, and Sang-gamma (gamma-BHC) $6\%$. Those insecticides were broadcasted by hand on the paddy field at the ratio of 3kg. in June and 4kg. in August per 10 a, and the date of insecticidal application was based on the maximum moth occurrence of the rice stem borer in 1969. The rice insect pests tested in this study were rice stem borer (Chilo suppressalis W.), green rice leafhopper (Nephotettix bipunctatus cincticeps U.), smiller brown planthopper (Laodelphax striatellus F.), and white back planthopper (Sogotella furcifera H.). For the study of residual effectiveness of the insecticides, the rice stem borer larvae just hatched from the eggs were installed on the sheath of rice plants collected from the paddy field after insecticidal treatment, and the mortality was made at 48 hours after installation. High mortality was observed in Terracur P and Sang-gamma treatments and low mortality in Lebaycid treatment. The duration of residual effects giving about 50% mortality was about 14 days in Sang-gamma and about 6 days in Terracur P treatments. The study on the effectiveness of the insecticides to the rice stem borer in the paddy field was made by the number of dead blades and white heads of the rice plants injured by the larvae, and the number of survival larvae in the straws after crop harvest. The order of insecticidal effectiveness to the rice stem borer was Terracur P=Sang-gamm>Lebaycid. The study on the effectiveness of the insecticides to the leafhoppers and planthoppers in the paddy field was made by the population density by sweeping (5 times) at the given day intervals after treatments. Terracur P was highly effective for the control of the green rice leafhoppers and Lebaycid was moderately effective, but Sang-gamma seemed not to be effective. The effectiveness of the insecticides tested to the planthoppers was not clear, and it seemed to related with the low insect population density. Study on the determination of proper timing of insecticidal application was not also made clear, and it seemed to be short in the range of day intervals in the insecticidal application. For the study on the control effects of the rice insect pests, rice yield per 100 hills per plot was observed. There was no statistically significant difference among the treatments in rice yields, but the order of yield (Terracur P>Sang-gamma>Lebaycid>Control) was paralleled with the tends of control effects above mentioned. In a view point of simultaneous control of the rice stem borers and green rice leafhoppers by the application of granulated insecticides, Terracur P and Lebaycid were more effective than Sang-gamma which have been used.
본 시험은 유기인계 살충제인 Terracur P입제 및 Lebaycid 입제와 유기염소계 살충제인 상감마입제$(\gamma-BHC 입제)$를 수면시용 하였을때 수도요해충인 이화명충, 끝 동매미충, 애멸구 및 흰둥멸구에 대한 동시방제가능성과 방제적기를 구명하고 약제간의 방제효과를 비교코저 실시하였다. 얻어진 시험결과는 다음과 같다. 1) 약제처리후 부화직후 이화명충 접종 시험에 있어서 상감마와 Terracur P는 높은 살충율을 보였으나 Lebaycid의 살충율은 낮았다. 約 $50\%$ 살충력 잔효일수에 있어서 상감마는 8-14日이었고 Terracur P는 6일간이었다. 2) 당초 계획된 방제적기에 관한 정보는 얻을 수 없었다. 즉 주어진 일간격이 좁아 유의한 차를 얻을 수 없었다. 3) 1,2화기 이화명충에 대한 방제효과는 Terracur P=상감마>Lebaycid의 순이었다. 4) Terracur P와 Lebaycid 입제의 처리는 끝동매미충의 방제효과가 좋았으나 상감마$(\gamma-BHC 입제)$의 방제효과는 기대할 수 없었다. 끝동매미충에 대한 Terracur P와 Lebaycid입제의 잔효력은 30일 이상이었다. 5) 애멸구와 흰등별구에 대한 시험은 충의 서식밀도가 낮기 때문에 약제간 방제효과를 얻을 수 없었다. 6) 공시약제중 Terracur P와 Lebaycidd입제는 이화명충과 끌동매미충의 동시방제제로서 사용할 수 있을 것 같다.