Acknowledgment

In this ant database, we used live ants as far as possible in our photography in order to reproduce as faithfully as possible the colors of ants found in the natural world. We would like to take this opportunity to express our profound gratitude to all those who kindly cooperated in the collection of the ants: Rikio Sonobe, Haruhiko Sakai, Katsusuke Yamauchi, Kyouichi Kinomura, Fuminori Ito, Hirofumi Watanabe, Seiki Yamane, Katsuyuki Eguchi and Hidetsune Takamine. Furthermore, we would like to mention that the hollotype of the rare species Rhopalomastix were lent to us by the Museum of Nature and Human Activities, Hyogo. At the same time, we are deeply grateful to Masaki Matsubara who provided us with invaluable technical support in the photography of ants by using Stereo Microscope (Olympus, SZX12), to Hideo Mitani of Nature Production who kindly gave us permission to digitize the booklets of Gakken's Photo Encyclopedia "Ants" and "The Ant Kingdom", and to Tokuko Imai who dedicated herself in all areas ranging from the photography of ants and data organization.

This ant database was supported with grants-in-aid from the Ministry of Education, Japan (1989-1991, 1993-1998), from Sokendai Collaborative Research (1997-2002) as well as from the Japan Science and Technology Corporation (2002).