The food plants and life cycle of Lymantria bantaizana were investigated in Iwate Prefecture, northern Honshu, Japan from 2000 to 2002. Eggs laid in July hatched approximately 10 days after oviposition. Hatched larvae fed only on Juglandaceae, Juglans mandshurica var. sachaliensis, J. regia var. orientalis and Pterocarya rhoifolia when reared in the laboratory. In field rearing, the plants of Juglans enabled the moth to complete its life cycle. Differing from all other known Lymantria species in Japan, the moth overwintered not in the egg stage but in the fifth or sixth instar larval stage. Lymantria bantaizana had eight larval instars in both sexes. Moth emergence occurred mostly in July at a field-trapping site in Iwate Prefecture.