Red Oak, Gypsy Moth Larvicide Test, Wooster, 1987

Oak seedlings (1-0) growing in 3-gal (11.3 liter) containers were used to evaluate efficacy of selected pesticides against fourth-instar gypsy moths. A CO2 compression sprayer with a Teejet SS8004 flat-fan nozzle operating at 20 psi was used to apply sprays to 3 single-tree replicates/treatment, each harboring 5 larvae. Sprays were applied 8 Jul to run-off to containerized trees growing in a greenhouse. Modified 1-gal (3.9 liter) Fonda cups were used to prevent larval escape. Tops and bottoms were removed from the cups. A bottom was secured around the base of each tree stem prior to larval placement and spray application. After spraying, Fonda cups were secured to bottoms, and nylon organdy cloth was fitted over the top. Treatment effectiveness was evaluated 1, 6, and 13 DAT by visually assessing larval mortality. Five additional larvae were placed on each replicate 48 h after treatment for all treatments except the insect growth regulator (IGR); larval mortality was assessed 96 h later. Foliage consumption of larvae on IGR treatments was compared with a standard insecticide-and-check treatment by using a leaf-area meter.