Abstract: A trial of completely randomized design was used to test the effect of methamidophos on the adults of Otidognathus davidis Fair., an insect of economic importance on bamboo shoots in China. Bamboo shoots were covered by nylon bags each containing five pairs of adults. High mortalities of adults were obtained from the treatments, and there were interactions between the height of bamboo shoots and the amount of the insecticide injected. Comparasions of control at different times showed a better result at adult stage than larvae stage in reducing damage by the insect.