红火蚁幼虫的杀虫剂敏感性及代谢酶活性研究

Insecticide Sensitivity and Metabolic Enzyme Activity of the Larvae of the Red Imported Fire Ant (Solenopsis invicta Buren)

为确定红火蚁幼蚁的杀虫剂敏感性,笔者利用点滴法测定了17种不同类型杀虫剂对红火蚁4龄幼蚁的毒力。毒力测定结果表明,供试杀虫剂对红火蚁4龄幼蚁的毒力均相当低,其LC50在639.28～3124.55μg/mL范围内,其中88.24%的药剂的LC50大于1000μg/mL,显示红火蚁幼蚁对杀虫剂的敏感性低。通过比较测定红火蚁4龄幼蚁和工蚁体内的羧酸酯酶(CarE)、磷酸酯酶、及谷胱甘肽-S-转移酶(GSTs)的活性,发现幼蚁的代谢酶比活力显著高于工蚁,特别是磷酸酯酶的比活力是工蚁的100倍以上。因此,认为幼蚁体内代谢酶活性高是其杀虫剂敏感性低的重要因素。

The insecticide sensitivity of larvae of the red imported fire ant （Solenopsis invicta Buren） was evaluated by the analysis of the contact toxicity of 17 insecticides of various types against the fourth instars reproductive larvae.It was found that the toxicities of the tested insecticides were relatively low with LC 50 from 639.28 μg/mL to 3124.55 μg/mL,amongst the LC 50 of 88.24% insecticides were higher than 1000 μg/mL.It was indicated that the larvae were insensitive to insecticides.In comparison of the activities of carboxyl esterases,phosphorases,and glutathione-S-transferases of the reproductive larval ants with those of worker ants,it was found that the specific activities of the measured metabolic enzymes in larvae were significantly higher than those in worker ants,especially the activity of phosphorases at folds of above 100,suggesting that strong activity of metabolic enzymes was an important factor for the insensitivity of larval ants to insecticides.