Green peach aphid (GPA); Myzus persicae (Sulzer)

Craig A. Longtine
Robert A. Suranyi
Edward B. Radcliffe
David W. Ragsdale

Department of Entomology
University of Minnesota
219 Hodson Hall
Saint Paul, MN 55108
Phone: (612) 624-2751
Fax: (612) 625-5299
Email: longt002@maroon.tc.umn.edu

CONTROL OF GREEN PEACH APHID, 1998: Experimental plots were established at the University of Minnesota Experiment Station, Rosemount, Minnesota. Potatoes were planted on 18 May. Treatments were replicated four times in a RCB design. Individual plots were 4 rows wide (36-inch row spacing) by 50 ft long with 12-ft alleyways separating plots. Admire was applied at planting using an electric powered "dribble" applicator attached to the planter placing the insecticide in-furrow ahead of the seed piece. All plots received a weekly application of fungicide (Polyram) and three applications of Asana to control potato leafhopper and uniformly increase the GPA population throughout the experiment. Spray applications were made using a tractor-mounted Brittonya boom sprayer with drop nozzles. Foliar insecticides were applied in 50 gpa at 80 psi on 28 Jul and 11 Aug. Sprayer equipment problems on 28 Jul hampered interpretation of results. The data presented are the number of GPA per 35 mid-plant leaves 3, 6 and 10 d after the second application of foliar insecticides. Analyses of variance were performed following transformation of count data using log₁₀ (x + 1), and means were compared using Ryan's Q test (significance level P = 0.05).

In general, all recommended insecticides (Monitor, Provado and Admire) when used at labeled rates gave adequate control of GPA. The lowest rates of Monitor and Admire, both below the recommended labeled rate, failed to give satisfactory control. The experimental products CGA-215944, CGA-293343, and Legend gave good control by 6 d after application. Asana and Penncap-M caused the GPA population to increase dramatically. Pirimor was not effective at the high GPA numbers present in this experiment.