Effect of common pesticides on sweet potato whitefly Bemisia tabaci (Hem.: Aleyrodidae) in fall cucumber at Ahwaz

Bemisia tabaci Gennadius was introduced over one hundred years ago and has seriously damaged the farming and non-farming products in the tropical regions. Many biological factors including host widespread range, being multi-generations, high productive rate, ability to transmission of the plant viruses and developing resistant to insecticides have been created many problems for managing this whitefly. In this research the effect of five insecticides. i.e. Pyriproxyfen, Imidaclopride, Pymetrozine, Fenpropathrin and Buprofezin on B.tabaci have been studied in order to determine the least most effective insecticide. By using leaf sampling, three leaves were chosen from upper, middle and lower parts of three shrubs. Totally nine leaves were selected from each plot randomly and the mature insects of pest lodging under leaves were counted. In order to count nymphs and puparium, the leaf pests were separated from stems and counted under a Binocolar. Subsequently, the obtained data were statistically analyzed and grouped at levels of %1 and %5. The results showed that none of the 10 treatments has an acceptable impact on nymph and puparium population. However, in adult pest insects the treatments Pyriproxyfen (Ec 10%) 750 cc/ha, Imidaclopride (SC35%) 750 cc/ha, Pymetrozine (WG25%) 1 kg/ha, Pymetrozine (WG25%) 1.25 kg/ha have had far superior results compared to the control group.