矿物油乳剂拒避橘小实蝇的有效组分分析

Assay of repellent components of mineral oils against the oriental fruit fly,Bactrocera dorsalis (Diptera:Tephritidae)

高品质的矿物油乳剂可用于有机食品生产,在害虫综合治理中有良好的应用前景。矿物油是包含多种化学成分的混合物,其组成成分和比例决定其理化性质并关系到其防治病虫害的效果。已有研究报道表明,矿物油乳剂对许多害虫有拒避作用,但其机理及相关性组成成分尚未研究清楚。本实验测定了4种矿物油乳剂即SK绿颖农用喷洒油、加德士-路易夏用油、安波尔喷洒油、法夏乐石蜡油(分别简称为SK,Caltex,Ampol和Citrole油)和Caltex油<120℃,>120℃,<105℃,105～120℃及SK油<110℃、>110℃等6种分子蒸馏组分的正构烷烃碳数当量nCy值、碳数分布值及其对橘小实蝇Bactroceradorsalis的产卵拒避效果。室内生物测定结果显示,橘小实蝇在SK,Caltex,Ampol和Citrole油0.5%水乳液及清水浸蘸处理后的香蕉上平均产卵孔数分别为17.850±1.282,3.400±0.630,15.850±1.439,20.650±1.212和19.050±1.155,在同样方法处理的阳桃上平均产卵孔数分别为15.500±3.969,3.000±0.707,13.750±4.131,17.250±4.385和62.000±4.708。橘小实蝇在6种分子蒸馏组分0.5%水乳液处理后的香蕉上的平均产卵孔数分别为4.400±1.166,8.200±0.583,5.400±1.720,2.400±1.077,4.800±1.594和12.200±2.63,显示不同矿物油的拒避效果差异显著(P<0.05),拒避效果最好的矿物油的正构烷烃碳数当量nCy值在nC23左右。矿物油对橘小实蝇的产卵拒避效果与其相应的碳数分布值的Spearman等级相关性分析显示,其拒避效果与矿物油中的C23组分的含量呈显著正相关关系(P<0.05)。这可为进一步分析矿物油乳剂拒避害虫的作用成分和探索其机理提供参考。

Mineral oils with high quality are seeing more recognition in modern pest management approaches and internationally accepted for use in organic farming as pesticides.Mineral oils are mixtures including a lot of components,and their components and proportion determined physical and chemical properties and pest control effect.The equivalent Normal-paraffin carbon numbers （nCy） and carbon number distribution of four mineral oils （SK EnSpray99,Caltex Lovis Miscible Summer Oil,Ampol D-C-Tron Spray oil,and Citrole paraffin oil）（hereinafter referred to as SK,Caltex,Ampol and Citrole oil,respectively） and six molecular distillation fractions （120℃,120℃,105℃,105-120℃ fractions of Caltex oil,and 110℃ and 110℃ fractions of SK oil） were determined and the oviposition repellent effects of their 0.5% aqueous emulsions against the oriental fruit fly,Bactrocera dorsalis,were bioassayed by dipping treatment in the laboratory.The results showed that the average puncture numbers of B.dorsalis on banana treated with SK,Caltex,Ampol,Citrole oil and water were 17.850±1.282,3.400±0.630,15.850±1.439,20.650±1.212,19.050±1.155,respectively,and those on starfruit were 15.500±3.969,3.000±0.707,13.750±4.131,17.250±4.385,62.000±4.708,respectively,and those on banana treated with 6 molecular distillation fractions were 4.400±1.166,8.200±0.583,5.400±1.720,2.400±1.077,4.800±1.594,12.200±2.63,respectively.There was significant difference in oviposition repellency against B.dorsalis among mineral oils （P0.05）,and nCy of mineral oils with the best repellent effect was nC23 or so.Correlation analysis of Spearman’s rank correlation coefficient （Spearman’s rho） test between carbon number distribution and oviposition repellency of mineral oils showed that there was a significant positive correlation between the repellent effect and the content of C23 of mineral oils （P0.05）.The results would be helpful to further research the repellent components of mineral oils against pests and the repellent mechanism.