A molecular gut content analysis reveals the feeding behavior of the Brown marmorated stink bug Halyomorpha halys

The Brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae) is one of the most harmful invasive species worldwide. It is highly polyphagous with the ability to feed on more than 170 different plant species, which were mostly described based on visual observations. Nevertheless, the exact feeding behavior of this important pest species is not known. We investigated the feeding behavior of H. halys using a molecular gut content analysis based on Oxford Nanopore sequencing on individuals collected in Northern Italy throughout the season and reconstructed the feeding behavior on an individual level. In total, we detected 65 plant genera belonging to 37 families, with Salix, Robinia, and Malus being the most frequent. Moreover, we newly described eight plant genera as feeding plants of H. halys. The number of plant genera within single individuals ranged from one to 17, highlighting a diverse host range and supporting the highly polyphagous nature of this species. Beta diversity analysis of host plants over the seasons showed significant differences and revealed different feeding hosts especially in the winter and summer months. The comparison with a previously published dataset on H. halys in Belgium showed that the main host plants were common across the two European regions, whereas less frequent plant taxa present in some individuals differed between the regions. Our results provide novel insights into the feeding behavior of H. halys contributing significantly to our understanding of the ecology of this important pest species.