3. Results
3.1. Data Sets
We selected the collection and identification records for 3110 sites (mostly forests) (Figure 1) in
which 71 taxa (64 species, 3 subspecies and 4 formas) were recorded (Appendix: Table A1). A hot
spot of species density was found in the central part of Japan (Chubu, Kanto and Tohoku) (Figure 1).
3.2. Regional Species Composition
The number of samples per unit area was highly biased. The islands of Tsushima and Ryukyu have
been surveyed intensively (sample/area (N/100 km2
) = 4.9 and 2.8), whereas less intensive records
were obtained for Hokkaido, Tohoku, Chubu, Chugoku, Shikoku and Kyushu. Species richness in each
region ranged from nine to 45 (Table 1), and was high in the central part of Honshu Island. (Kanto and
Chubu). The difference between the actual and expected (Chao1) number of species [57] in each
region was large in Kinki and Shikoku. However, the species richness was also high in Kanto
and Chubu.