The rice water weevil is an insect native to the southern US, where its native food was grass. Following the introduction of rice into the US, the weevil shifted from grasses to feed on rice. This shift was first reported in the 1880s. In the late 1950s, the insect was found in northern California rice fields. From there, the weevil was carried across the Pacific into Asia in the mid-1970s. First detected in China in 1988, the rice water weevil has become a major rice pest and has spread all across the country.

“The rice water weevil was recognized as an important invasive pest immediately after its discovery in mainland China because of the severe rice yield losses. The adults feed on the upper leaf surfaces producing longitudinal scars. Larval feeding on roots causes stunted growth, yellowing of the leaves (chlorosis) and plants that are easily uprooted, resulting in few tillers and low grain yield. In mainland China yield losses typically exceeded 10% in the established paddies, but approached over 80% in newly infested areas.”

“Insecticides provide the most effective means of controlling the weevil in China as they do in the United States and Japan.”

Authors: Chen, H.¹, Z. Chen² and Y. Zhou²
Affiliation: ¹ Department of Biology, SUNY-Buffalo; ² Plant Quarantine Institute, Beijing, China
Title: Rice water weevil (Coleoptera: Curculionidae) in mainland China: Invasion, spread and control.
Publication: Crop Protection. 2005. 24:695-702.