Assessing rice stink bug, Oebalus pugnax (F.) (Heteroptera:Pentatomidae), damage in rice

To determine the impact of rice stink bug Oebalus pugnax (F.) in rice, individual rice panicles were infested using adult rice stink bugs in sleeve cages (10x20cm) in Stoneville, Mississippi. Infestation densities included one or two rice stink bugs per panicle compared with caged non-infested panicles at three stages (bloom, milk and soft dough) of panicle development. Twenty panicles per treatment were investigated and relative injury among infestation densities and timings were assessed. By all measures of yield and quality, rice stink bug injury by percentage weight (g) was significant {non-infested (13.09±1.76c), one stink bug (33.40±3.54b), 2 rice stink bugs (51.51±3.97a)} at bloom (first 7 days after flowering) and milk {non-infested (10.60±0.67c), one stink bug (22.76±2.11b), 2 rice stink bugs (35.25±3.47a)} stages. Discolored kernels (pecky rice) were significantly higher (number/panicle) at the milk stage {non-infested (12.55±1.36c), one stink bug (22.45±2.15b), 2 rice stink bugs (33.35±2.51a)} compared to bloom {non-infested (5.47±1.32a), one stink bug (11.00±2.22a), 2 rice stink bugs (11.26±2.73a)} and soft dough {non-infested (10.45±2.21b), one stink bug (14.05±1.78ab), 2 rice stink bugs (18.10±1.65a)} stages. The results suggest that rice is most susceptible to rice stink bug injury during the first two weeks of panicle development, and that the impact of rice stink bug on rice changes with panicle development.