Grapholita molesta (Busck) is a major pest of stone fruits. Immature fruits of apricot and plum are well known food source during early summer for G. molesta, but those immature fruits have rarely been evaluated. Thus, we assessed biological and behavioral attributes of G. molesta when provided with immature fruits of apricot and plum in laboratory. The initial response rate (when larva reached to the center from release point in Y-tube olfactometer) of first instar was not different between apricot (70.0%) and plum (60.0%) of which sugar content was more on plum (5.92 brix in apricot and 7.30 brix in plum). However, pupal weight was less in apricot (7.5 mg) than in plum (11.4 mg), and this might be affected by difference in hardness of the fruits (17.2 N on apricot and 13.3 N on plum). The preoviposition period was also longer in apricot (6.3 d) than plum (3.6 d), and fecundity was lower on apricot (64.5) than on plum (135.0). Therefore immature plum fruit would be better food source for G. molesta than apricot during early summer.

• Souvic Sarker(Department of Plant Medicals, Andong National University)
• Un Taek Lim(Department of Plant Medicals, Andong National University)