Abstract
A new bioassay method for Thrips palmi, called the CST (Cucumber Seedling Treatment) method, was established. The CST method is characterized by easy chemical application, easy observation, long observation period, high survival rate and high reproducibility. The 1st-instar larvae attached to a cucumber seedling grow healthily, and the rate of pupation and emergence is very high (90%-100%). These merits enable evaluation of slow-acting compounds, such as chitin synthesis inhibitors and hormone analogues. In the CST method, the feeding damage appears as dead spots on the leaves, and visual evaluation of control efficacy is easy. The CST method can be used to determine susceptibility of Thrips palmi to insecticides with different modes of action.
