The occurrence and damage of stink bugs were monitored at South Korea from 2007 to 2008. A total of 11 stink bug species were observed in paddy field and occurrence periods of stink bugs were significantly differed by species. In occurrence period and damage of stink bug feeding in paddy field, Scotinophara lurida occurred from June, Cletus punctiger, Eysarcoris aeneus, Rhopalus maculatus, Riptortus clavatus, E. ventralis, Stenotus rubrovittatus occurred from August and Pachygrontha antennata, C. schmidti, Trigonotylus caelestialium, Paromius exiguus occurred from September. When we were classified into two region with mountain and plain area cultivated rice, generally C. puntiger population was higher in mountain area than plain area, and E. aeneus was higher in plain area than mountain area. Also, stink bug species were higher in environment condition formed with a paddy field and a waterway overgrown with weeds. Control threshold for E. aeneus in paddy field was 1-2 individuals/heading stage, and then rate of pecky rice made to 5.0% while milk stage, dough stage and yellow ripe stage made to less than 5.0%.

This study was carried out to survey the occurrence of stink bugs and pecky rice grain caused by the stink bugs in paddy fields in six districts of Gyeonggi-do. In the levee of the paddy fields, 30 species of the stink bugs were collected, and the dominant species were Paromius exiguus in Hwaseong and Siheung, and Stenotus rubrovittatus in Pyeongtaek, Icheon and Paju. In the paddy fields, 23 species were collected, and the dominant species were Paromius exiguus in Siheung, and Stenotus rubrovittatus in Pyeongtaek, Icheon and Paju. P. exiguus overwintered and proliferated mainly in the west coastal region, where its host plants, Imperata cylindrica and Calamagrostis epigeois, were abundant, and then moved to paddy fields later in the season, resulting in the peak density in September in paddy area. Stenotus rubrovittatus and Cletus punctiger were abundant in paddy area in August and September, and Eysarcoris aeneus was abundant in June and July. When the stink bugs were inoculated on the rice, the rate of pecky rice caused by E. aeneus and P. exiguus at milk ripe stage was 10.2% and 4.8%, respectively, and the rate by S. rubrovittatus and P. exiguus at dough ripe stage was 4.3% and 2.7%, respectively. The damage shape of pecky rice was distinctive according to the species. The surface of pecky rice by P. exiguus was very smooth but the surface of pecky rice by E. aeneus was rough and caved. In the pecky rice by S. rubrovittatus, the spot occurred at the topside of the grain.