Occurrences of Rhopalosipnum rufiabdominalis damage in the leaves of Japanese apricots were observed in Hadong, Gyeongnam Province, a major producing area. R. rufiabdominalis occurred from early May to mid October, with the peak occurrence of damaged leaves in mid May. To find proper timing of chemical control against R. rufiabdominalis, acetamiprid WP was sprayed weekly from 3 April, before budbreak, to 8 May in 2007. The best time for control R. rufiabdominalis was on 17 April 2007, at which the leaves were still tender and developing up to 3 to 5 leaves.