The sugar apple is one of the important fruit trees in Taitung district, Twenty species of pest insects (belonging to 6 orders, 13 families) and 5 species of spider mites was recorded as sugar apple pests from 1983 to 1988, The survey on seasonal fluctuation showed that the highest pest population density of Anonapestis bengalella larvae appeared between June to August and November to December; Scirtothrips dorsalis was between May to July and October to November, Highest population density for, Planococcus citri was observed between July to September and November to December and for Oligonychus coffeae between November to January, Four species of mitioulid beetles (belonging to Coleoptera and Nitidulidae) had the highest activities on sugar apple flowers between May to July and October to November.