Colorado Potato Beetle Control, 1997

Abstract Seventeen insecticide treatments were tested at the M.S.U. Research Farm, in Entrican, MI, for the control of Colorado potato beetles (CPB). ‘Snowden’ potatoes were planted 12 inches apart with a 34-inch row spacing on 21 May. Treatments were replicated four times and assigned to plots in a RCB design. Plots measured 45 ft in length and three rows wide. The Admire, CGA-293343 4 FS, CGA-293343/CGA-173506 1.5%, CGA-293343/CGA-173506 2.0%, and Temik treatments were all applied at planting. The first foliar treatment was applied at 40% CPB hatch on 23 Jun using a tractor-mounted sprayer (30 gal/acre, 40 psi). Subsequent first-generation sprays were applied on 1 Jul and 7 Jul. Agri-Mek and Agenda were applied on 23 Jun and 7 Jul only. Spintor (both rates) was applied on both 23 Jun and 27 Jun. Alert and Acrobat were applied on each of the spray dates. Insecticide effectiveness was determined by counting various stages of CPB on four or three randomly selected plants from the middle row of each plot. A count of four plants was done on 25 Jun. Counts of three plants per plot were done on 3 Jul, 10 Jul, and 18 Jul. Due to light CPB pressure due to a cold spring and early summer, second-generation sprays were not needed this year. All plots were sprayed with Agri-Mek on 23 Jul for the second-generation beetles present. Each plot was assessed for defoliation on 3 Jul and 10 Jul. The middle row of potatoes from each plot was harvested on 4 Sep, separated by size and weight.