Both rice stink bug, Oebalus pugnax, and barnyardgrass, Echinochloa crus-galli, are pests of rice. Observations suggest that presence of barnyardgrass in rice fields causes an increase in stink bug populations. Field experiments were conducted in 2001 and 2002 to determine if presence of barnyardgrass influences stink bug infestations. In both years, more stink bugs were found on rice in plots of barnyardgrass and rice than in whole plots of rice before panicle emergence of rice. In 2001, stink bugs were up to nine times more abundant on rice in plots of barnyardgrass and rice compared to whole plots of rice after panicle emergence. In 2002, stink bugs were 1.5 times greater on rice in whole plots of rice than in plots of rice and barnyardgrass after panicle emergence of rice. Differences are likely a result of differences in the developmental stage of barnyardgrass relative to rice. In 2001 barnyardgrass emerged with rice; in 2002 barnyardgrass emergence was delayed by four weeks. Data suggest that when barnyardgrass produces seed heads before rice, barnyardgrass can serve as a source of stink bug infestation. However, if barnyardgrass seed heads are present when panicle emergence of rice occurs, the barnyardgrass may serve as a ‘trap crop’ for stink bugs. Data suggest both the presence and developmental stage of barnyardgrass, relative to rice, influence the severity of rice stink bug infestations. This experiment is currently being repeated to address the impact of presence and developmental stage of barnyardgrass on populations of rice stink bugs.
Species 1: Heteroptera Pentatomidae Oebalus pugnax (rice stink bug)
Keywords: insect-weed interactions, rice
Back to Student Competition Ten-Minute Papers, Cd2, Behavior and Ecology
Back to Student Competition TMP Orals
Back to The 2003 ESA Annual Meeting and Exhibition