Spanworm Control, 1997

Abstract

Abstract Materials were applied on 1 Jun (Test 1), and 30 May and 6 Jun to 20- by 20-ft plots in a bearing blueberry field at Jonesboro, Maine. There were 4 replications of each treatment and a minimum 5-ft untreated buffer strip around each plot. Treatments were blocked according to prespray population levels. Insecticides were applied at a rate of 25 gpa using a CO2-propelled 80-inch boom sprayer, with 4, flat-spray 80002VS TeeJet® nozzles operating at 35 psi. At treatment, larvae were first to third instar and plants were 5-10% bloom (Test 1). For Test 2, plants were < 5% bloom on 30 May and 35-40% bloom on 6 Jun. On sample dates indicated in the table, 10 sweeps with a standard 12-inch sweep-net were taken systematically through the center area of each plot avoiding plot boundaries. Any SW larvae were counted and then distributed back into the same plot. For Test 2, on each of 3 dates (30 May, 3 Jun, and 8 Jun), SW larvae were collected from a plot which had been treated with Mycotrol ES. The larvae were surface disinfected with zephiran chloride, maintained in the laboratory, and observed for sporulation of Beauveria bassiana. The only significant rainfall during the trial occurred on 4 Jun when 1.02 inches of rain was recorded.