<p>The introduction of brown marmorated stink bug <i>Halyomorpha halys</i> (Stål), a highly polyphagous agricultural pest insect, to grape-producing regions has raised concerns about economic impacts on wine grapes. Semi-field experiments were carried out on grapes of the ‘Pinot noir’ cultivar to identify crop susceptibility to late-season feeding damage by <i>H. halys</i>. Treatments consisted of three life stages (hatching eggs, nymphs, or adults) of <i>H. halys</i> and a control group. Insects were placed on bagged clusters in either sunny or shaded regions of the vine canopy for four weeks to assess how microclimate variation within vineyard blocks affects <i>H. halys</i> mortality and feeding activity. Observed adult mortalities were compared to simulated values from a physiologically based population model that employed temperature as the main driving variable. When temperatures differed between shaded and sunny locations, the model produced different estimates of mortality dependent on location type, coherent with experimental data. At harvest, clusters were inspected for presence of salivary sheaths, and grape characteristics were measured. Feeding activity, as approximated by sheath counts, was highest on clusters exposed to feeding by adults in sunny locations, indicating that shading may affect the spatial distribution of insect damage in grapes. However, higher <i>H. halys</i> feeding activity did not consistently reduce cluster mass, grape berry mass, berry diameter, or soluble solids. Our results indicate that moderate densities of <i>H. halys</i> are unlikely to inflict measurable yield loss to ‘Pinot noir’ grapes post-véraison.</p>