Study on Toxicity and Control Effect of Mixture of Abamectin and Imidacloprid to Lipaphis erysimi

The result of the laboratory test showed that the co-toxicity coefficient of the mixture of abamectin and imidacloprid (mass ratio 1 : 1) to Lipaphis erysimi (Kaltenbach) was 244. 38. Its toxicity being 1. 6 times as that of abamectin and 4. 9 times as that of imidacloprid, the synergism of the mixture was remarkable. In the field trial, the control effects of 1 000, 2 000 and 3 000 times of the 1% mixture abamectin and imidacloprid suspension concentrate to L. erysimi were 98. 79%, 96.63% and 94. 31% respectively 7 days after application.