Abstract
Insecticidal activities of methanol extracts of the different parts of Prunus mume were investigated against the larvae of Cnaphalocrocis medinalis (C. medinalis) by topical application. The mortalities of the larvae of C. medinalis were 34% at the concentration of 4,000 ppm, 36% of 8,000 ppm, 40% of 16,000 ppm and 58% of 32,000 ppm of the extracts from the fruits, and 38% of 4,000 ppm, 45% of 8,000 ppm, 58% of 16,000 ppm and 75% of 32,000 ppm from the stem + flower of Prunus mume (P. mume), respectively. The rates of pupation of C. medinalis treated with either fruit or stem+flower were gradually low according to the concentration of extracts increased. The weight of pupae of C. medinalis has no significantly different in between the control and the treated groups of the extracts from both of fruit and stem+flower. However, the differences of the pupal weight and the rate of pupation of C. medinalis treated with the extracts from the stem+flower and fruit of P. mume were significant as the level of 56% ($R^2$=0.56363, P=0.4364). Both of stem+flower and fruit extracts of P. mume showed good effects of anti-feeding against C. medinalis. The extracts of the stem+flower of P. mume could be advocated for developing as birational agent for the control of C. medinalis.
흑명나방 3령 유충에 대한 매실나무 부위별(줄기+꽃, 열매) 메탄올 추출물의 살충활성과 용화율 및 용무게의 변화를 조사하였다. 매실나무 열매에 대한 살충률은 4,000 ppm에서 34%, 8,000 ppm에서 36%, 16,000 ppm에서 40%, 32,000 ppm에서 58% 값을 보였고, 줄기+꽃에 대한 살충률은 4,000 ppm에서 38%, 8,000 ppm에서 45%, 16,000 ppm에서 58%, 32,000 ppm에서 75%의 살충활성을 보였다. 매실나무 열매와 줄기+꽃 추출물을 혹명나방에 처리하였을 때 용화율은 농도가 증가함에 따라 서서히 낮아졌다. 용무게는 대조구과 처리구에서 별 차이점을 보이지 않았으나 용화율과 용무게에 대한 상관관계를 비교하여 분석한 결과 매실나무 열매 추출물보다 줄기+꽃 추출물에서 상대적으로 높은 유의성을 나타냈다. 또한 혹명나방의 섭식저해율은 두 가지 추출물에서 60%이상의 살충률을 보이며 섭식저해와 더불어 섭식독으로써 효과가 있음을 보였다.