Toxicity Detection And Synergistic Insecticides Screening Of Five Pesticides Against Aphis Gossypii

Aphids are important agricultural pests,which are characterized by rapid propagation,many species and short generation period.Therefore,the research and development of new pesticides has attracted particular attention of researchers as an efficient,safe,and economical aphicide.In this study,the Aphis gossypii was used as the test object.The toxicity of Aphis gossypii to pymetrozine,cyantraniliprole,flonicamid,clothianidin,and dinotefuran was tested by indoor bioassay test.A two-component compounding system was used to initially select several combinations with significant synergies.The field efficacy trial was conducted to select an efficient synergistic.The main results are as follows:1.Toxicity testing of five insecticides to Aphis gossypiiThe Aphis gossypii was used as the test object.The susceptibility of Aphis gossypii to pymetrozine,cyantraniliprole,flonicamid,clothianidin,and dinotefuran was tested by indoor bioassay test.Among them,The results showed that cyantraniliprole,flonicamid,clothianidin,and dinotefuran had high toxicity to the tested aphids.The LC₅₀ of the five insecticides were:pymetrozine 369.63 mg/L,cyantraniliprole 129.34 mg/L,flonicamid 107.37 mg/L,clothianidin 24.71 mg/L,dinotefuran 16.51 mg/L.2.Mixing and screening of different agentsAccording to the different mechanism of insecticide action,three groups of agents of cyantraniliprole+clothianidin,flonicamid+pymetrozine,cyantraniliprole+dinotefuran were mixed.According to the mixed proportions of lethal concentration of the single agent,the mixture of cyantraniliprole+clothianidin were selected at 1:1,3:1,5:1,7:1,9:1,11:1,13:1.The mixture of flonicamid+pymetrozine was selected at 3:1,1:1,1:3,1:5,1:7 for synergistic screening.Selecting 1:1,4:1,8:1,10:1,12:1,14:1,16:1 of cyantraniliprole+dinotefuran to conduct a synergistic screening test for the mixed agents.The results showed that except the cyantraniliprole+clothianidin 3:1,the cyantraniliprole+dinotefuran 1:1 and 4:1 three groups of mixed coordinate synergism is not obvious,the rest of the group mixed agents has the effect of different degrees.3.Preliminary investigation of field efficacy trialsThe results of field efficacy trials showed that the percentage of the control effect of 6 g a.i./hm² 2%cyantraniliprole:clothianidin?9:1?mixture to aphids was 95.36%in 1 day,which was the highest and was significantly higher than other treatments.The highest percentage of the control efficacy of the 120 g a.i./hm² 5%clothianidin WP and the 6 g a.i./hm² 2%cyantraniliprole:clothianidin?9:1?mixture were 97.76%and 97.23%,which was significantly higher than other treatments in 3 days.The percentage of the control effect of the 120 g a.i./hm² 10%cyantraniliprole OD was the second which was 94.31%.The 30 g a.i./hm² 10%floxacamide SC was relatively poor,and the percentage of the control effect was 70.99%.In 7days,the best control effect was 120 g a.i./hm² 10%cyantraniliprole OD and 120 g a.i./hm² 5%clothianidin WP which percentage were 99.99%and 100.00%.In 14 days,the control effects of each treatment were above 95%.Three treatments of 10%cyantraniliprole OD and 60 g a.i./hm² 10%floxacamide SC exist significant difference with 60 g a.i./hm² 25%pymetrozine WP,30 g a.i./hm² and 60 g a.i./hm² 20%dinotefuran SC,with no significant difference between other treatments.From the point of view of the entire 14-day control effect,all the tested agents achieved good control effect.