Rice water weevil (Coleoptera: Curculionidae) in mainland China: Invasion, spread and control

The rice water weevil, Lissorhoptrus oryzophilus Kuschel, is the most important species among invasive insects in China. The parthenogenic weevil, first detected in Tanghai County of Hebei Province in 1988, has become one of the major rice pests in China with yield loss of 10-80%. Since then, the pest has expanded its range of infestation at a rate of 10-30 km/year. This pest has been found in eleven provinces and two large municipal areas infesting over 400,000 ha by late 2003. Quarantine measures did not effectively limit the spread of rice water weevil due to its parthenogenesis, flying, swimming and hitchhiking on human transportation. The weevil's life history, population dynamics, host-plant relationships and mode of establishment have been studied at a number of locations. Currently, the pest is managed by integration of insecticides, water management, delayed transplanting, blacklight trapping, application of Beauveria bassiana and Metarhizium anisopliae spores and rice cultivars with tolerance to the rice water weevil.