Abstract: The mango leaf-cutting weevil Deporaus marginatus Pascoe is a major pest to cause severe defoliation of mango Mangifera indica L..The life history showes 4 generations,and a small part 3 generations in Yunnan Province where the weevil appears in April and remains damaging up to November.This pest overwinters mainly as grubs in the soil with only a few adults on the host tree.Egg,larva,pupa and adult durations are 2~3,7~10,10~4 and 7~15 days respectively.Three larval instars have been observed.In this paper,the infesting behaviour of the pest insect is described in detail.The functions of several natural enemies are mentioned.The management measures are given including ploughing the orchard soil in the dry season,collecting and burning the fallen leaves on the ground every 3~5 days during the rainy months,and spraying insecticide occasionally according to the infectation level.