Developmental Biology and Seasonal Damage of the Grape Borer Xylotrechus pyrrhoderus in Grapevines

<i>Xylotrechus pyrrhoderus</i> Bates (<i>Coleoptera: Cerambycidae</i>) is a major viticultural pest whose larval feeding damages grapevine canes and reduces yields, yet its internal development and damage progression are poorly understood. Using field surveys combined with micro-computed tomography (micro-CT) and in situ X-ray microscopy, we non-destructively tracked both tissue damage and life-cycle dynamics within canes. Damage intensity increased from December to May, with affected canes showing reduced porosity compared to healthy ones. Continuous imaging revealed a distinct prepupal stage and extended adult residence in pupal chambers before emergence. Morphometric analysis showed that adult size is constrained by pupal chamber dimensions, indicating adaptive adjustment to limited intra-cane space. These findings demonstrate the value of advanced imaging tools for clarifying the biology of <i>X. pyrrhoderus</i> and support the development of targeted management strategies for this and related agricultural pests.