Abstract ‘Superior’ white potatoes were planted on 29 Apr in a Sassafras sandy loam soil. Plots consisted of 3 rows of potatoes, each being 20-ft long and 3-ft wide, arranged in a randomized complete block design with 4 replications. Treatments were applied with a self-propelled, high clearance sprayer with one drop nozzle on each side of the row and one over the center of each row calibrated to deliver 59 gal/acre at 40 psi operated at 2 mph. Bacillus thuringiensis (M-One 5.6%) treatments were applied at a rate of 2 qts/acre. Plot A was treated at approximately 33% CPB egg hatch (4 Jun), plot B treated 2 days later (6 Jun), plot C treated 2 days after plot B (8 Jun), plot D treated 2 days after plot C (10 Jun) and plot E was untreated. All plots received a second and third treatment 7 and 14 days, respectively, after their first treatment. Percent plant defoliation caused by Colorado potato beetle was recorded on 16 and 26 Jun. The number of potato hills with at least one stalk in flower was recorded on 20 Jun. Numbers of small CPB larvae (first and second instars) and large (third and fourth instars) larvae/5 hills were recorded on 16 Jun, and numbers of large larvae were again recorded on 26 Jun. Plots were harvested and yields (cwt/ acre) were recorded on 9 Sep. All data were taken from the middle row.