Abstract Three insecticide evaluation studies were conducted for control of mixed populations of northern and western corn rootworm. Experiment I was conducted at the Pennsylvania Agricultural Experiment Station farm at Rock Springs, Centre County, PA. Corn was planted on 15 May using a 6-row John Deere Max-Emerge planter with 30-in row spacing. Insecticides were applied to 15 by 90-ft plots in a randomized complete block design with 4 replications per treatment. Rows 1 and 6 were nontreated guard rows. The plots were thinned to 115 plants per 90 ft of row. On 31 Jul 5 plants from each replication were evaluated for root damage ratings based on the Iowa 1 to 6 system with 6 being the most severe damage. Yield was determined by mechanically harvesting 3 middle rows from each plot for shelled corn. Experiment II was conducted on the Drew Smith farm near Pleasant Gap, Centre County PA. Corn was planted 21 May using a 2-row John Deere Max-Emerge no-till planter with 30-inch row spacing. Insecticides were applied to 5 × 50 ft plots in a randomized complete block design. The Dyfonate encapsulated was applied 22 May with flat fan drop nozzles over the row from a small plot sprayer. Root damage ratings were evaluated over the period of 7 through 9 Aug, taking 5 plants per plot and using the Iowa 1-6 system. On 25 Oct 17.5 ft of row was hand harvested per plot and yield was determined. Experiment III was conducted on the Dan Stoltzfus farm near Mill Hall, Clinton County, PA. Corn was planted on 21 May using the same planter and field design described in experiment II. Root damage was determined on 6 Aug and yield as determined on 23 Oct.