Abstract
This experiment has been carried out in order to rear the rice stem borer, Chilo suppressalis WALKER, through successive generations with artificial diets under the aseptic condition. The results obtained were summarised as follows:
1. An improved diets contained high amount of choline chloride to obtain normal moths, and the moths deposited fertile eggs through five generations under the aseptic condition.
2. Of the experiments following two kinds of diets seemed to be suitable for rearing the rice stem borer.
3. There was few difference between this borer reared on the two kinds of diets and those on rice plant in the paddy field in the weight of matured larvae, rate of pupation and number of egg masses layed.
4. Though the number of normal female and of normal eggs were increased by the improved diets containing high amount of choline chloride (0.2-0.3g per 200ml of Erlenmeyer flask), the results obtained were not sufficient compared with that of wild one.
5. When the wild male mated with the female reared on the artificial diets, the rate of egg hatching was increased in some grade. But this increasing of the rate was decreased in the next generation.
6. From the results in this experiment, it is expected that Shonai-ecotype of this insect can be reared for about 10 generations and Saigoku-ecotype 6 generations in a year under non-diapause conditions on the artificial diets.
