Study On Monitoring Of Insecticide Resistance, Synergisms And Biochemical Mechanism Of Myzus Persicae(Sulzer)

Myzus persicae (Sulzer) is a global pest of agriculture. The susceptibility of field samples of Myzus persicae (Sulzer) to 8 kinds of commonly used insecticides in Hubei Province was examined. Joint actions for mixtures of insecticides in aphid were evaluated by bioassays, and relationships of synergistic effects of the mixtures to metabolic enzymes were studied by biochemical tests. The major results were described below:1. Dip test technique was used to monitor the susceptibility of Myzus persicae to 8 kinds of insecticides in 4 field populations in Hubei province collected in Wuxue, Zaoyang, Xiantao and Yichang respectisely. The results showed that compared with the relatively susceptible colony, the population collected in Hubei province didn't produce high level resistance. The field populations produced low level to moderate level resistance to imidacloprid, and low level resistance to acetamiprid and abamectin. The populations were still low susceptible or susceptible level to others insecticides.2. Synergistic effects of 8 kinds of insecticides in Myzus persicae were assessed. Results showed that diafenthiuron+imidacloprid(8.5:1), nitenpyram+chlorfenapyr(1:6.7), and imidacloprid+chlorfenapyr(1:3.8) were the optimum ratio with of co-toxicity coefficient (CTC) 250.11,125.57 and 201.51. The result of the field experiments showed that 3 kinds of mixtures against Myzus persicae had good control effect.3. Influences of 3 kinds of mixtures and their corresponding single dose on metabolic enzymes in Myzus persicae were studied. In vivo tests, activities of CarE and GSTs were induced by treatments with sublethal dose (LC20) of imidacloprid, diafenthiuron, chlorfenapy and diafenthiuron+imidacloprid, and were reduced by treatments with sublethal dose of nitenpyram and nitenpyram+chlorfenapy. Activities of CarE were induced by treatments with sublethal dose of imidacloprid+chlorfenapy and of MFO were inhibited by treatments with sublethal dose of diafenthiuron, chlorfenapy, nitenpyram and nitenpyram+chlorfenapy.