Field insecticides trial against cowpea aphid (Aphis craccivora) and Liriomyza sativae.

Insecticides of 2.5 % imidacloprid EC,2.5 % lambda-cyhalothrin EC,5 % acetamiprid EC,100 g·L-1 alpha-cypermethrin EC and 25 % buprofezin WC were used for field trial against cowpea aphid(Aphis craccivora).Insecticides of 480 g·L-1 chlorpyrifos EC,4.5 % cypermethrin EC,80 % dichlorvos EC,75 % cyromzinge WP and 0.5 % emamectin benzoate EC were used for field trial against Liriomyza sativae.The results showed that 1 500 times dilution of 2.5 % imidacloprid EC,2 000 times dilution of 2.5 % lambda-cyhalothrin EC,1 000 times dilution of 5 % acetamiprid EC and 2 000 times dilution of 100 g·L-1 alpha-cypermethrin EC could effectively control cowpea aphid and the efficacy were all above 95.76 % during 1 day to 10 days after control.The efficacy of 1 000 times dilution of 25 % buprofezin WC was very low and it was only 66.68 % in 3 days after spraying.3 000 times dilution of 75 % cyromzinge WP had good control effects on Liriomyza sativae and its efficacy was 89.63 %,94.10 % and 93.28 % differently after 3 days,7 days and 10 days.The secondary efficacy was given by 480 g·L-1 chlorpyrifos EC,with control effect of 61.12 %,69.15 % and 69.40 % after 3 days,7 days and 10 days.The other insecticides all had very low efficacy.