Oebalus poecilus (Dallas) is an important pest affecting irrigated rice in Rio Grande do Sul, Brazil. It hibernates during the coldest months of the year in refuges such as bamboo litter. This study examined O. poecilus hibernation to determine the causes of mortality during this period. The study was conducted in a 140 m² bamboo plantation located in a rice-growing area in Eldorado do Sul County (30° 02’ S and 51° 23’ W), RS. During June 2000 to April 2002, 63 samples of litter were taken in weekly or fortnightly intervals, and the number of bugs recorded in the laboratory. The arrival at the hibernation site (bamboo litter) began in the first fortnight of March, and was completed in the beginning of May. O. poecilus left this refuge from middle October to the end of December. Parasitism by tachinid flies and Beauveria bassiana (Bals.) Vuill. fungus were the most important mortality factors.
overwintering; small rice stink bug; parasitism; Beauveria bassiana
