The relationship between a stand’s net brood production and its stand susceptibility index is, to a large extent, determined by the relationships between DBH vs. tree-level net brood production and DBH vs. basal area. Basal area, i.e., the area of the cross-section of a tree trunk at breast height, is the metric used in the stand susceptibility rating systemto quantify tree mortality, and increases exponentially with increasing DBH. The net production of beetles per tree also increases exponentially with increasing DBH. We generated curves of the rate of increase for these two relationships to determine the tree diameters that contribute most, per tree, to any discrepancy between net brood production and stand susceptibility rating. The estimated generalized net brood production was calculated according to ‘‘step 1’’ described above.