苦楝果提取物对美国白蛾生物活性的影响

为了探讨苦楝果作为杀虫剂的效果,对苦楝果的乙醇和乙酸乙酯提取的活性物质对美国白蛾4龄幼虫的影响进行了研究。结果表明:苦楝果乙醇和乙酸乙酯提取物对美国白蛾幼虫具有明显的拒食、生长抑制和触杀作用,其生物活性与浓度成正相关。乙醇提取物的拒食和生长抑制作用要优于乙酸乙酯提取物的,但是乙酸乙酯提取物的触杀作用比乙醇提取物的要好。处理24、48和72 h乙醇提取物和乙酸乙酯提取物的拒食中浓度分别为1.10 mg/mL、0-87 mg/mL、0.62 mg/mL和1.88 mg/mL、1.29 mg/mL、1.04 mg/mL;处理24 h,5.00 mg/mL浓度下乙醇提取物处理的幼虫体重成负增长状态,抑制率为100%,而乙酸乙酯提取物的抑制率为83.55%;处理48 h乙醇提取物和乙酸乙酯提取物的致死中浓度分别是4.35 mg/mL和1.99 mg/mL。

Effect of extracts Melia azedarach on ovicidal activity of Hyphantria cunea Drury

In order to explore the effect of Melia azedarach as pesticide,the ethanol and acetidin ex- tracts from Melia azedarach to Hyphantria cunea Drury were studied.Results indicated that the extracts from Melia azedarach with ethanol and acetidin had antifeeding,inhibition of growth and toxic,and the ovicidal activity was closely related to the concentration.Antifeeding and inhibition of growth of ethanol ether extracts were better than acetidin ether extracts,but toxic of acetidin ex- tracts was better than ethanol extracts.Treatment for 24,48 and 72h the median antifeeding con- centrations of ethanol and acetidin extracts was 1.10 mg/mL,0.87 mg/mL,0.62 mg/mL and 1.88 mg/mL,1.29 mg/mL,1.04 mg/mL;Treatment for 24 h,50 mg/mL concentrations of ethanol ex- tracts the larvae growth was negative and growth inhibition ratio was 100%,and acetidin extracts growth inhibition ratio was 83.55%.In 48 h after treatment the LC_(50)of ethanol and acetidin ex- tracts was 4.35 mg/mL and 1.99 mg/mL.