Feeding damage on hazelnuts by Halyomorpha halys, brown marmorated stink bug (Hemiptera: Pentatomidae)

Halyomorpha halys (Hemiptera: Pentatomidae), commonly known as brown marmorated stink bug (BMSB), is a pest on a wide range of crops in the eastern United States. BMSB has been established in Oregon since 2003 and poses a serious threat to Oregon agriculture. A preliminary study was done to characterize feeding damage that BMSB could inflict on hazelnuts, one of Oregon’s main specialty crops. Mesh sleeves were placed over hazelnuts branches when the nuts began developing. Adult BMSB males were placed in each sleeve. The insects were left to feed for two weeks before being moved to more mature clusters of nuts. This was repeated every two weeks until harvest. The nuts remained bagged until harvest after insects were removed. At the end of the season nuts were collected and examined for damage. Damage was found to occur at all hazelnut developmental stages in this study. Early nuts had aborted or stunted development while later nuts showed high percentages of corking, including those with mature shells. Nuts not exposed to BMSB had higher percentages of healthy nuts that those exposed. The study will be continued for two more seasons to confirm these initial trends.