Control of Colorado Potato Beetle Larvae with Foliar Insecticides, 1983

‘Russet Burbank’ potatoes were planted at the Northwest Experiment Station, Crookston, Minn., on 17 May, and at the Red River Valley Potato Growers Research Farm (RRVPGA), Grand Forks, N.D. on 14 May. Plots were of variable length with 38-inch row spacing, randomized in complete blocks with three replications. All beetle larvae were counted on every plant in each replication until a minimum of 200 larvae were reached. Insecticide treatments were applied using a CO2 powered hand-sprayer delivering 38 gal water/acre at 30 lb/in2. Treatments were applied on 6 Jul. in Crookston and evaluated on 7 Jul. and 14 Jul. On the RRVPGA research farm, treatments were applied on 13 Jul. and 21 Jul. and evaluated on 14 Jul. and 22 Jul. At the Crookston location, the larvae were predominantly 1st to 3rd instar while those on the RRVPGA research farm were 2nd to 4th instar.