Abstract: HNPC-A3066(E)methyl 2- -1-methylthio methylideneaminooxymethylphenyl-3-methoxyacrylate is a novel strobilurin miticide discovered in China.Miticidal activity of HNPC-A3066 to two spot red spider (Tetranychus urticae) was tested in the laboratory using miticidal bioassay techniques.The results showed that HNPC- A3066 had a good contact and ovicidal action,but a weak systemic activity to the phytophagous mites.The LC50 value of HNPC-A3066 against female adult mites by leaf-dipping and slide-immersion method was 3.03 and 4.02 mg/L at 48 h after treatment,respectively,and the LC50 value against nymph mites and eggs was 0.74 and 2.02 mg/L at 24 h and 7 d after treatment,respectively.Field trial results demonstrated that HNPC-A3066 exhibited a good control efficacy against two spot red spider,European red mite(Panonychus ulmi) and citrus red mite(Panonychus citri),and their average control efficacy was more than 70.88%,75.33% and 72.65%,respectively,at 1 d,3 d, 7 d and 14 d after application at the concentration of 80 and 160 mg/L,and it was safe to beneficial insects and crops.