Duration of rice stink bug, Oebalus pugnax (F.) infestation impacts the milk stage of panicle development

Abstract

Oebalus pugnax (F.), is a late-season pest of rice during the reproductive stage. A two-year field study was conducted in Stoneville, Mississippi, to characterize and evaluate various O. pugnax infestation durations on rice yield and quality at the milk stage (R5.5-R6.5) of panicle development. In 2011, twenty adult O. pugnax were caged individually on ˈWellsˈ panicles for 3, 5, or 7 days regardless of sex. The experiment was repeated in 2012 to include a 1-day infestation duration and a sex-controlled infestation of 10 males and 10 females caged individually on ‘Wells’ and ‘Cocodrie’ rice identification of panicles. The weight and percentages of the filled, undamaged, damaged, and blank kernels per panicle were evaluated. Filled kernel weight did not differ significantly amongst the various O. pugnax infestation durations. The undamaged kernels decreased with increasing infestation duration between 11% and 21% relative to the control treatment. The damaged and blank kernels increased with increasing infestation duration between 113–262% and 27–192% for the damaged and blank kernels, respectively. The average single kernel weight for undamaged, damaged, and blank kernels was 24, 13, and 4 mg, respectively. The damaged kernel resulted in a 46% weight reduction relative to the undamaged kernel. Female O. pugnax infestations resulted in a greater yield and quality reduction than male infestations. This study provides Mississippi rice producers, with first-hand information of O. pugnax feeding duration on kernel yield and quality. Future studies on the milling quality and identification of fungi pathogens associated with Mississippi rice may be desirable.

Keywords

• Rice stink bug
• kernel discoloration
• infestation duration
• milk stage
• damaged kernel
• grain quality