Taxus, Black Vine Weevil Control, Lancaster, Pennsylvania, 1975

A nursery planting of 12-yr-old intermedia taxus near Lancaster, Pennsylvania, heavily infested with black vine weevil larvae (range = 1-78, x = 32/ft3 of soil) was chosen for insecticide evaluation. The soil types in this area are characterized as Letort silt loam and Conesroga silt loam. The plants were growing in a block of 4 rows 42 inches apart consisting of ca. 110 plants/row. We divided the block into 11 sections, each measuring 30 ft x 19 ft. On July 22, 1975, one of 9 treatments was applied to each section using a modified hand-held, rotary grass seed spreader. The experimental area received 1 inch of irrigation water from overhead sprinklers immediately after treatment. Plants were observed August 8 for phytotoxicity. Treatment effectiveness was evaluated November 12-19 by examining cubic foot samples of soil from beside each of 3 plants in each of 3 rows/section for larvae.