Butterfly fauna of Tama Forest Science Garden, Forestry and Forest Products Research Institute [Japan]

Butterflies so far collected in Tama Forest Science Garden (TFSG) of Forestry and Forest Products Research Institute, Hachioji City, Tokyo Metropolis, were described. A total of 69 butterfly species were recorded, including two locally extinct species, Luehdorfia japonica and Eurema laeta, represented by only a few old specimens and four recent invaders, Papilio memnon, Narathura bazalus, Argyreus hyperbius and Melanitis phedima. Beside the 69 species recorded by the specimens, Neptis pryeri was once recorded during the 1930's in literature. Taking this species into consideration, there have been 70 species of butterflies so far recorded and three of which have been extinct from TFSG. Papilio memnon was thought to be a stray species, whereas the other species could breed in TFSG at least temporalily. Two migratory species, Narathura bazalus and Lampides boeticus, were thought not to overwinter, and seven rare and/or mobile species, Choaspes benjaminii, Byasa alcinous, Taraka hamada, Argyreus hyperbius, Cynthia cardui and Nymphalis xanthomelas, were thought not to be constant residents in TFSG. Among 104 resident species recorded from Hachioji City, including those extinct from the city, 35 were not found from TFSG, but three of them, i.e. Argyronome laodice, Argyronome ruslana and Fabriciana adippe, and once locally extinct Neptis pryeri are known from adjacent areas and may still remain to be discovered from TFSG in the future. Forest dwelling species of East Asian (Sino-Japanese) elements were the dominant in the TFSG butterfly fauna. These species mostly coincided with a group of butterflies representing the fauna of "satoyama" (coppice forest used to be managed for fuel wood and manure production) in the suburbs of Tokyo, indicating that TFSG has been keeping this declining group of butterflies in reserve. Five mountainous species, Papilio macilentus, Papilio maackii, Artogeia nesis, Celastrina sugitanii and Araschnia burejana were also found. The butterfly fauna of TFSG indicated good conditions of the environment.