Comparative Study on Biological Activity of Eight Neonicotinoid Insecticides

In order to provide reference for scientific application,the biological activities of 8 neonicotinoid insecticides were compared,including imidacloprid,acetamiprid,nitenpyram,thiacloprid,thiamethoxam,clothianidin,imidaclothiz and dinotefuran.The bioassays were carried out by dipping method for bean aphid(BA),rice seedling dipping method for brown planthopper(BP) or striped rice borer(SRB),and leaf disk dipping method for diamondback moth(DM).The testing data were grouped,and the relations between structure and biological activity were analyzed.The LC50values of these neonicotinoid insecticides were 0.031 4-0.350 5 mg/L to BA,0.565 7-49.404 6 mg/L to BP,7.517 6-139.036 9mg/L to SRB,and 10.533 4-100 mg/L to DM,respectively.Insecticide activities were influenced by closed-loop or opened-loop of nicotinyl and substituted heterocyclic,etc.The activities on homopteran were significantly superior to lepidopteran.Rotation and double administration could promote the scientific and reasonable use of these insecticides in practical applications,and the technology of seed treatment is really worth paying attention to.