Efficiency of cyantraniliprole on Plutella xylostella (L.) and its residual dissipation dynamics in Brassica oleracea

The efficiency of cyantraniliprole on Plutella xylostella was studied, and the residue dissipation dynamics of cyantraniliprole in Brassica oleracea was analyzed. According to the research result, a safe application method of this insecticide was developed to provide a guideline for the application of cyantraniliprole in the field. Field trials by different doses indicated that 10% cyantraniliprole OD at the available dosage of 21 g/hm2 had good control effect (92.8%-98.3%) from 24 h to 7 d after the application of the pesticide. The results of residue tests showed that the half-life of cyantraniliprole in B. oleracea was 3.86 d when the 10% cyantraniliprole OD was applied once at double recommended dosages (42 g a.i./hm2). The residue risk in the harvested B. oleracea was positively correlated with application dose and spraying frequencies. The safety interval was suggested to be 3 d in the open field if the recommended dosages (21 g a.i./hm2) was applied no more than 2 times.