An experiment on the control of Sitodiplosis mosellana with 40% chlorpyrifos EC.
In an experiment carried out in a wheat growing area in Wuwei of Gansu Province in 2000, 40% chlorpyrifos EC was used to control S. mosellana. The population density of the insect was 135 heads/m2 before control. Treatments of 48% chlorpyrifos EC at 100, 150, 200, and 250 ml/mu (1 ha = 15 mu) added with 2.5 kg water were sprayed onto 20 kg fine sands and stirred up evenly, then broadcast onto wheat fields during the pupal stage of the pests before irrigation. The results of observations by peeling off wheat ears showed that 48% chlorpyrifos EC at the above application rates all effectively controlled pest damage, with an efficacy of 88.04-95.08%. Very significant differences in control efficacy between application rates of 100 ml/mu and 250 ml/mu were observed and no significant differences among the application rates of 150, 200 and 250 ml/mu. Therefore, 48% chlorpyrifos EC at the application rate of 150 ml/mu is recommended for control of S. mosellana.