Western bean cutworm (WBCW) (Richia albicosta, Smith) is a secondary pest of corn in the western portion of the US corn belt. Economic loss from this ear-feeding pest is temporally and spatially sporadic across its distribution. Wide-area testing characterized Herculex I efficacy of this pest. Subsequently, the product use guide was amended to include WBCW and a voluntary stewardship plan was established. Herculex I plants provide very good efficacy against WBCW and preliminary laboratory bioassay data described susceptibility that was less than high-dose as defined by the FIFRA Scientific Advisory Panel (April 1998). This is not uncommon for secondary pests of corn products with lepidopteran protection using plant-incorporated-protectants. One aspect of the stewardship plan for Herculex I efficacy against WBCW includes a study of baseline susceptibility. These results will provide a benchmark for investigating suspected field resistance. Results from this two-year study are reported with an emphasis on alternate monitoring methods appropriate for target pests that are moderately susceptible to Bt proteins.