Abstract: This paper reports the results of a study on the sugar cane weevilTrochorhopalus humeralis Chevrolat, the most destructive soil-inhabiting pest of the sugarcane stumps in Yunnan. The study was conducted mainly in Luxi County, Yunnan Province, during 1989-1991. Data obtained from both laboratory observations and field survey show that the weevil passes one generation a year and overwinters in adult stage in the host stumps. The biological characteristics and behaviour of the different stages are described. Recommended control measures are mainly agrotechnical practices such as crop rotation between sugarcane and rice, keeping off two-year old rhizome of ratoon which should be ploughed out and burnedup in early spring (before mid March), etc. Applying insecticidal granules such as 3% Isofenphos-methyl or 5% Temik into the planting ditch near the host roots is also effective.

Key words: sugarcane weevil, Trochorhopalus humeralis Chevrolat, bionomics, ag- ricultural control measures