Abstract: Gilpinia massoniana is a new forest pest occurred in Changchong Forest Farm of Chu County, Anhui Province, whose major host is Pinus massoniana. According to the survey conducted in May, 1991, the area infested by the pest was about 9000mu. It has 2 generations a year. It pupates under the litter, in the root part of the grass or in the soil from mid-June to early July and from late October to mid-November, and aestivatea and hibernates by prepupa. The larva has 6 instars, feeding on an average of 573.1 cm of the needle during the period of lst~5th instar. After entering into the 6th instar, the larva feeds on nothing and makes cocoon in 5 hours to 2 days. The sex ratio of the adults is 1:1. After mating, the female lays eggs on the needles, the average number of an egg mass is 87.6. It mainly distributes in the pure P. massoniana forest of 20~30 years old, especially in the sparse forest and forest border. The pest can be effectively controlled by 10% Fenvalerate or 10% Mevinphos.