Effects of infestation timing and number of rice stink bug, Niphe elongata (Hemiptera: Pentatomidae) on rice grain sterility

Abstract

To investigate the influence of infestation by and number of rice stink bug, Niphe elongata (Heteroptera: Pentatomidae) on rice grain sterility, we released adult bugs at the rate of 0.125, 0.25, or 0.5 per rice panicle, at 0, 7, or 14 days after heading to feed for 7 days. Degree of grain growth decreased with the number of bugs released and with earlier release. Estimated grain sterility was 21.1%, 15.4% and 9.6% when bugs were released on the day, 7 days and 14 days after heading at a rate of one bug per plant, respectively. These results suggest that grain sterility increases with the number of adults, in the early ripening period, but it is less likely to increase with the number of adults in the mid-ripening period.