The bionomics of the pierid Eurema hecabe which infests seedlings of Acacia mearnsii was studied in Nanping, Longxi and Fujian, China, in 1985-87. Nine generations were produced annually and the larvae overwintered. Pupation began in the middle of February and adults emerged in early March. The larva had 5 instars, with fuligrown larvae pupating on the branches of A. mearnsii. The main natural enemies of E. hecabe were the chalcidid Brachymeria lasus, the ichneumonid Coccygomimus sp. [Pimpla sp.] and scelionid wasps. Ninety percent trichlorfon (diluted 1000 times) or 50% phoxim (diluted 2000 times) gave good control of the pest. The morphological characters of the egg, larva and adult are described and illustrated. none