Control Effects of Five Pesticides on Greenhouse Whiteflies

To compare the control effect and determine the optimal concentration,five pesticides,20% Bete-cypermethrin,20% Aceta,10% Imidacloprid,2.0% Abamectin and 25% Fenproathrin were applied to Euphorbia pulcherrima to control greenhouse whitefly.The experiment was conducted in May 2010 in the Qinghai high-tech agricultural development company.The results showed that the best control effect was 800-fold dilution of 20% Bete-cypermethrin,the corrected control effect after 1,3,5 d was 73.87%,92.60%,74.95%,respectively;followed by 1 000-fold dilution of 20% Acetamiprid and the corrected control effect after 1,3,5 d was 62.47%,80.54%,67.48%.To avoid the greenhouse whitefly resistance,20% Acetamiprid could be used as a replacement of 20% Bete-cypermethrin.The control effect of diluted 25% Fenproathrin was above 40% and that of 3 000-fold dilution of 10% Imidacloprid was the lowest.