ショウジョウバエ集団の生態学的研究

The present studies have been undertaken in a hope to analyse ecological and genetical features of flies belong to the genus Drosophila, on the basis of material derived from research work, done in Hokkaido, the northern most island of Japan, and in San-In region, Iying a south-western part of Japan, during a period from 1954 to 1962.
Data obtained are to be described in four parts separately in the present paper.
In Part I, the results of some ecological studies in drosophilid flies are described, regarding specially their geographical distribution in Hokkaido. Additionally, some accounts on the seasonal behavior of flies observed in the University Botanical Garden, Sapporo, and in some other localities of this island, during a period from 1954 to 1956 were reported in Part I. Part II deals with some ecological studies carried out in San-In region during five successive years ranging from 1957 to 1961, with special reference to their geographical distribution in that region, together with some supplementary data on seasonal behavior observed on Mt. Dakesan, near Matsue City, in 1961. Data derived from some statistical analyses regarding population structure of Drosophila are to be presented in Part II. Part III was devoted to the investigations of chromosomal polymorphism in D. nigromaculata based on the material collected in the University Botanical Garden, during a period from late June to October, 1962. The results may involve some important criteria for understanding of the evolutionary process of organisms in general. In Part IV are described some experimental results on the preference of two Drosophila species to some kinds of yeasts ; evidence presented seems to be essential for the analyses of the mechanism of attractive behavior of flies to fruit-baits in the field.