Studies on Population Ecology of Thrips palmi KARNY : XV. Evaluation of Effectiveness of Control Methods Using a Simulation Model

抄録

The effectiveness of various control methods was simulated using a population model of Thrips palmi on cucumber cultivated in a plastic greenhouse, and an effective control system was sought. Since the required frequency of spraying lessens as the control threshold (CT) lowers because of the low density effect, CT must be set as low as possible. The "pursuit" spraying method (insecticide is sprayed when the population exceeds the control threshold level and several days aftr the spraying regardless of population density) is effective to reduce the frequency of spraying. The frequency of periodical spraying started at very low density is almost the same as that using CT, making it an effective means. From the standpoint of safe use of agricultural chemicals, it is difficult to control T. palmi using insecticides alone. Prevention of greenhouse invasion, reduction of density on seedlings and mass trapping using sticky traps are other effective means of T. palmi control.