Abstract
To census the present butterfly fauna of Rinshinomori Park, Tokyo (the site of the National Forestry Research Center), I conducted field surveys on 203 days from 2010 through 2019 and recorded 40 species: 8 papilionid, 5 pierid, 9 lycaenid, 15 nymphalid, and 3 hesperiid species. By Tanaka’s criterion (Tanaka 1988), they comprise 25 forest species (62.5%) and 15 grassland species (37.5%). The Sunose environmental index was 74 that indicates a “moderate natural environment”. On the geographical distribution of the recorded species, the percentage of Himalayan-type (15.0%) species was higher and those of Siberian-type (15.0%) and Ussuri-type (5.0%) species were lower than the national averages in Japan. Percentages of forest, univoltine, egg diapause (overwintering) and Chinese-type species such as Antigius attilia and Japonica saepestriata have declined in comparison with the data collected in the park in 1970s by the National Forestry Research Center.
