Assessment of Rice Stink Bug, Oebalus pugnax, Damage to Grain Sorghum

The rice stink bug, Oebalus pugnax, is known to feed on the developing kernels of Grain Sorghum, and work has established thresholds which identify the point at which control is necessary. Until recently populations of rice stink bug have gone unnoticed, as many producers only look for a few established pests in grain sorghum. With the arrival of the sugarcane aphid, increased scouting and awareness has identified large populations of rice stink bug in developing sorghum fields. The threshold for Arkansas is based off work that is over 30 years old, and many question whether 5 stink bugs per head is still valid. The objective of this study was to assess the ability of rice stink bug to damage grain sorghum at population levels around the current threshold.

                Damage to grain sorghum was assessed by infesting rice stink bug (rsb) on to sorghum heads using sleeve cages. Five infestation levels (0, 2, 5, 10, and 20 rsb per head) were applied across four stages of head development (emergence, flowering, soft dough, and hard dough). For each combination of infestation level and infestation timing, 10 replications were performed at each of three growing regions: Northeast, Central, and South East Arkansas.