Occurrence Regularity And Prevention Of Phyllotreta Striolata In Hangzhou

Phyllotreta striolata is an important pest on cruciferous vegetables,and its damage is increasing year by year in the south of the Yangtze River in China.Long-term and single use of chemical pesticides has increased the resistance of Phyllotreta striolata.This study provides reference information for the formulation of agricultural prevention and control measures by investigating the occurrence regularity;through indoor single agent screening and compounding,and comparing with the field control effect of production drugs,it provides a new choice for chemical control.The results are as follows :1.Effects of different cultivation conditions : The peak period of beetles in greenhouse environment occurred at an average temperature of 28℃,and in open environment occurred at an average temperature of 24℃.Effects of different planting patterns : the peak period was similar,the small peak was in the second to third weeks after sowing,and the large peak was in the fifth to sixth weeks after sowing;the peak values were different.Chinese cabbage intercropping pepper could effectively reduce the insect population density than monoculture,and the highest control effect could reach 46 %.2.Laboratory test : The indoor toxicity of four kinds of original drugs to Phyllotreta striolata was :pyridaben > cyantraniliprole > acetamiprid > metaflumizone.The LC50 values of pyridaben and cyantraniliprole were 28.854 mg/L and 110.083 mg/L.The three combinations of pyridaben and cyantraniliprole with effective mass ratios of 17∶44,23∶22 and 26∶11 showed synergistic effects,and the co-toxicity coefficients(CTC)were 215.8,147.8 and 156.5,respectively.3.Field control effect : 15 % pyridaben EC and 10 % cyantraniliprole OD were compounded at an effective mass ratio of 17∶44,and the control effect was significantly higher than that of the two single agents on the 7th and 14 th day after treatment,but not as good as the new drug 10 % flubendiamide SC.The control effect was 40 % ～ 50 % 3 days after treatment.After 7 days,the best control effect of 10 %bromoflubendiamide SC reached 73.73 %,and the second control effect of 15 % pyridaben EC and10 % cyantraniliprole OD was 59.56 %,which was significantly higher than that of two single doses.After 14 days,the control effect of 10 % bromoflubendiamide SC was 46.92 %,and the control effect of 15 % pyridaben EC combined with 10 % cyantraniliprole OD was 32.95 %.