抄録
1. The experiments on the parasitization of a parsite wasp, Mormoniella vitripennis to housefly pupae were performed, and the results in two kinds of environment were compared. 2. Two kinds of media for fly larvae viz. medium A and B (Refer to Figure 1 and 2) were prepared. A grass pot (16cm in diameter) was separated into four sections, two of them of diagonal position were filled with medium A and the other two were filled with medium B. 3. Housefly larvae were reared in these pots, and the fly pupae in each section were counted. In this combination of media, fly pupae were found more abundant in medium A than in medium B. The result seems to show that the medium A was more attractive and suitable for fly larvae. 4. The experiments on the parasitization of Mormoniella vitripennis to fly pupae reared in such combination of media were made and the percentages of parasitization in each medium were observed. As the results of the experiments, high percentages of parasitization were observed in medium A. By these attacks of the parasite wasp, the number of emerged flies were highly reduced in medium A, but those from medium B was not so much reduced than in medium A. 5. Whereas the difference of the percentages of parasitization is taken place in these two media, it is concluded that the abundance of emerged houseflies depends not only to the suitability for the growth of the larvae but also to other environmental factors such as the existence of parasite wasp etc.
