Abstract
Outbreaks of the rice water weevil, Lissorhoptrus oryzophilus Kuschel were found in rice fields of Aichi prefecture on May 1976. This is the first record of invasion into Japan. Distribution of this outbreaks were spread by the flood of rice fields. The adult feeding on leaves of younger rice plants and the larva pruning rice roots were observed in the rice fields of early planting cultivation. Formation of the cell (cocoon) attached to the rice roots was observed, and the new adult could be found in Summer. The species overwinters in adult and has one generation a year in Aichi. They are probably increased by parthenogenesis.
