In field experiments conducted in 2005 and 2006, panicles of rice, Oryza sativa L., were infested for 48 h with one male or female rice stink bug, Oebalus pugnax (F.), at heading, milk, soft and hard dough stages of development. Number of grains, number and weight of filled grains, number and weight of empty grains, and percentage whole kernels per panicle were not significantly affected by infestation at any stage of panicle development, nor were any significant differences found in percentage peck caused by male or female O. pugnax. In 2005, percentage peck was significantly lower in uninfested panicles and panicles infested during hard dough than in panicles infested during heading, milk or soft dough. No differences were found in percentage peck caused by O. pugnax during heading, milk or soft dough. In 2006, no significant differences were found in percentage peck produced by O. pugnax in panicles infested during heading, milk, soft dough or hard dough. Higher percentage peck in hard dough may have been the result of late drainage of the field.