常用杀虫剂对螺旋粉虱与六斑月瓢虫生物活性及选择毒力

为明确常用杀虫剂对螺旋粉虱和六斑月瓢虫的选择毒力，提高螺旋粉虱的防治水平，采用浸渍法和药膜法测定了3种常用杀虫剂对螺旋粉虱及六斑月瓢虫的生物活性。结果表明，供试3种杀虫剂均对螺旋粉虱表现出一定的生物活性，其中在对螺旋粉虱成虫的活性中以高氯苯油毒力最高，其LC50值为4.1482 mg/L，对3龄若虫的毒力测定中，辛硫磷活性最高，其LC50值为6.7367 mg/L。对六斑月瓢虫的安全性评价结果表明，辛硫磷表现出较高的选择毒力，其对螺旋粉虱成虫和3龄若虫对天敌六斑月瓢虫成虫的选择性指数分别为12.1869和15.1077。在螺旋粉虱成虫和3龄幼虫盛发期可分别选用高氯苯油和辛硫磷作为防控药剂，但在天敌六斑月瓢虫数量较多时，可选择辛硫磷，以协调螺旋粉虱的化学防治和生物防治。

Bio-activity and Selective Toxicity of Insecticides to Aleurodicus disperses Russell and Menochilus sexmaculata Fabricius

In order to clear the selective toxicity of commonly used insecticides to Aleurodicus disperses Russell and Menochilus sexmaculata Fabricius and improve the management level of A. disperses, the means of impregnation and residual film were used to detect the bio-activities of 3 insecticides to A. disperses and M. sexmaculata. The results indicated that all insecticides used showed toxicity to A. disperses, β-Cypermethrin and Phoxim showed the highest toxicity to adults and 3 instar of A. disperses and the LC 50 were 4.1482 mg/L and 6.7367 mg/L, respectively. In safety evaluation, phoxim showed best selective activities between M. sexmaculata and A. disperses, the selective ratios were 12.1869 and 15.1077 between M. sexmaculata and adults and 3 instar of A. disperses. β-Cypermethrin and phoxim should be used in full incidence period of adult and 3 instar of A. disperses, while phoxim should be used to coordinate the chemical and biological control of A. disperses when natural enemy M. sexmaculata was abundance.