Cranberry, Grub Control, 1984

Granular insecticides were applied on 21 May at Site 1 and 15 May at Site 2 using a hand shaker made from a pint jar with perforated lid. Treatments were arranged in a 5 X 5 Latin square of contiguous, 7 x 7-ft plots at Site 1 and in 3, widely separated randomized blocks of 12 x 8-ft plots at Site 2. A portable overhead irrigation system was used to apply about 2.5 inches of water to each site in a 20 h period. The soil at Site 2 consisted almost entirely of sand, whereas that at Site 2 contained much organic matter. Pre- and post-treatment grub counts were done in the same manner. At Site 1, four, square-foot samples dug to a depth of 6 inches were removed from each plot, placed on a large, plastic sheet, and examined for both grub species. At Site 2, four, 2 x 2-ft samples were dug to a depth of 4 inches in each plot, rolled back, and inspected for P. anxia. Counts were made 16 and 9 days prior to treatment and 21 and 24 days after treatment at Sites 1 and 2, respectively. All specimens were placed in plastic vials, identified in the laboratory, and classified according to head capsule width.