红蓼提取物对13种农业害虫触杀活性的研究

关于红蓼提取物对农业害虫的触杀活性,国内外研究甚少。研究红蓼提取物对害虫的触杀活性,可为利用该植物研制新型植物源杀虫剂提供理论依据。本研究采用浸渍法测定了红蓼提取物对害虫的触杀活性,结果表明,红蓼种子乙酸乙酯萃取物对粘虫、菜粉蝶、棉铃虫、甘蓝夜蛾、甜菜夜蛾和小地老虎4~5龄幼虫具有很强的触杀活性,在16.80 g/L浓度下的校正死亡率在87.50%~100%;对小菜蛾3龄幼虫也具有很强的触杀活性,在21.00 g/L浓度下的校正死亡率为92.85%;秋季茎秆乙酸乙酯萃取物对菜粉蝶4龄幼虫和粘虫5龄幼虫具有很强和较强的触杀活性,在33.60 g/L浓度下的校正死亡率分别为100%和59.20%。盛花期茎秆石油醚粗提物对棉蚜具有较强的触杀活性,在0.27 g/L浓度下的校正死亡率为51.65%。盛花期花石油醚和甲醇粗提物对朱砂叶螨具有很强的触杀活性,在0.13和1.15 g/L浓度下的校正死亡率均高达100%。

A study on contact toxicity of extracts from Polygonum orientale against 13 species of agricultural pests

Contact toxicity of extracts from Polygonum orientale against agricultural pests have seldom been researched.A study on contact toxicity of the extracts can provide a theoretical basis for formulating new types of botanical insecticide.Contact toxicity of the extracts against pests was carried out by the immersion method.Ethyl acetate extract from seeds of P.orientale had very strong contact toxicity against 4th or 5th instar larvae of Mythimna separate,Pieris rapae,Helicoverpa armigera,Mamestra brassicae,Spodoptera exigua and Agrotis ypsilon.Percentages of corrected mortality were between 87.5% and 100% when the concentration of the fraction was 16.80 g/L.The fraction also had very strong contact toxicity against 3rd instar larvae of Plutella xylostella,with a corrected mortality of 92.85% when the concentration of the fraction was 21.00 g/L.The ethyl acetate fraction from stems of P.orientale collected in fall had very strong contact toxicity against 4th instar larvae of P.rapae or 5th instar larvae of M.separate with corrected mortalities of 100% or 59.20%(33.60 g/L).Petroleum ether extract from stems of P.orientale in blossom had stronger contact toxicity against Aphis gossypii,with corrected mortality of 51.65%(0.27 g/L).Petroleum ether and methanol extracts from flowers of P.orientale in blossom had very strong contact toxicity against Tetranychus cinnabarinus,with corrected mortality of 100%(0.13 and 1.15 g/L).