Reconsidering the importance of <scp> <i>M</i> </scp> <i>etopolophium dirhodum</i> ( <scp>W</scp> alker) ( <scp>H</scp> emiptera: <scp>A</scp> phididae) as a crop pest

Abstract Barley yellow dwarf virus (BYDV) causes major yield losses in temperate cereals. In many regions, management of BYDV has focused on Rhopalosiphum padi as the primary vector of BYDV‐PAV and Sitobion avenae as the primary vector of BYDV‐MAV. By contrast, the significance of Metopolophium dirhodum beyond its summer feeding damage is less clear. Although M. dirhodum can transmit both BYDV species, its role in driving disease outbreaks has received limited attention in management discussions, and its field occurrence and population biology under Irish conditions remain poorly studied. This study addresses this gap by examining the seasonal presence and life‐history parameters of M. dirhodum in temperate barley systems. National field monitoring (2022–2025) using yellow‐pan traps and in‐field tiller assessments confirmed regular occurrence of M. dirhodum in Irish barley crops, with consistent spring barley establishment and occasional winter barley colonization, demonstrating distinct seasonal phenology compared to S. avenae . In terms of life‐history, all clones showed high fecundity and extended adult longevity. Population parameters indicated strong reproductive potential, with intrinsic ( r ) and finite ( λ ) rates of increase consistent with a capacity for rapid population growth under favourable conditions. This study provides the first integrated assessment of M. dirhodum population biology and seasonal dynamics in Ireland, and our findings demonstrate that the species maintains stable field presence and strong reproductive capacity on barley, reinforcing its status as an important component of national aphid‐monitoring and integrated pest management programmes.