Effects of hazelnut cultivar and phenology on Halyomorpha halys, a key hemipteran pest

As the brown marmorated stink bug (Halyomorpha halys) has expanded its range into North America and Europe, this species has emerged as an economically important pest of hazelnut (Corylus avellana). Some observational studies suggest that H. halys exhibit feeding preferences among cultivars (CVs), but experimental evidence is currently lacking. In semi-field feeding experiments, we found that the developmental success of H. halys nymphs generally increased with advancing nut maturity but also varied among CVs, with some appearing highly suitable and other relatively unsuitable for supporting nymphal survival. Additionally, we conducted headspace sampling to assess whether different CVs exhibited distinctive volatilome characteristics and tested H. halys physiological and behavioral responses to select hazelnut volatiles. Our results provide insights into the foraging ecology of H. halys as a primary hazelnut pest.