日本列島におけるチヨウ類およびハムシ類の地理的分布にみられる規則性

抄録

The purpose of the paper is to analyse some regularities constituting the local insect fauna, based on the data of the geographical distributions of butterflies of the Japanese Archipelago including Ogasawara Is. and of leaf beetles of the Ryukyu Archipelago and the Island of Yakushima. 1) Relations of the total number of species (y) to areas (x). On the geographical distributions of butterflies of the Japanese Archipelago, the regression line and correlation coefficient are : log y=0.281 log x+0.971,r=+0.902,DF=68 On leafbeetles of the Ryukyu Archipelago and the Island of Yakushima, the formula is : log y=0.286 log x+1.083,r=+0.967,DF=4 2) Relations of average size of genera to the total number of species. The average number of species per genus increases in accordance with the increase of total number of species. However, in the case of butterflies the relations of the total number of genera (y) to the total number of species (x) can be given approximately by the following formula with correlation coefficient : y=0.652 x+5.141,r=+0.997,DF=68 In the case of leafbeetles, by : y=0.548 x+9.160,r=0.986,DF=4 3) Relations of index of diversity of genus to total number of species. Simpson's index of diversity (1949) is useful to examine the concentration or diversity of generic size in areas. The value increases in accordance with the increase of total number of species. The relations of index of diversity of genus (y) to total number of species (x) is given by : y=0.696 x+26.297,r=+0.866,DF=68 In the case of leafbeetles, by : y=0.614 x+27.769,r=+0.726,DF=4 (P (4,0.1)=0.729) In the case of leafbeetles the level of significance is only slightly larger than 10 per cent. Since there is little evidence available on this regularity, it is necessary to accumulate further evidence from other taxonomic groups.