Characterizing Brown Marmorated Stink Bug Injury in Almond, a New Host Crop in California

The brown marmorated stink bug, Halyomorpha halys (Stål), is an invasive species from Asia. This polyphagous, stink bug species has posed a serious production challenge in several crop species in the areas where established. The insect has spread to all the mainland states in the U.S. in about one and half decades after its first detection in Pennsylvania. The types of crops reported to have been infested by this stink bug have increased with its spread to new geographic locations. In this study, we report the first evidence of H. halys infestation in almond fruit in California. In Stanislaus County, an adult brown marmorated stink bug in an almond orchard was first observed in May 2017. The stink bug feeding on almond fruits caused excessive gumming to the developing fruits, and damage to the kernels along with typical necrotic feeding signs on the shell (endocarp) and hull (exocarp and pericarp) of the fruit at harvest. The infestation and damage by H. halys on almond warrants further research to develop Integrated Pest Management (IPM) strategies for this pest.