Spring Control of Japanese Beetle Grubs on a Golf Course Fairway at Hershey, PA, 1983

Nine insecticides were applied 13 May for control of Japanese beetle grubs. The fairway consisted of annual bluegrass (70%) and colonial bentgrass (30%). Treatment plots were 10 by 10 ft, arranged in a RGB design and replicated three times. Liquid formulations were applied in 3 gal of water with a hand-held sprinkling can. Granular formulations were applied with a hand-held shaker, followed by watering in with 3 gal water. After all treatments were completed, the entire treated area was irrigated for 20 min. At treatment time, the following environmental and soil conditions existed: air temperature, 78°F; soil temperature, 74°F; soil type, loam; soil pH, 6.5; soil condition, wet; percent organic matter, 2.9; amount of thatch, 0.25 to 0.5 in; and clear skies. Posttreatment counts were made 2 8 days later (10 Jun.). Four ft2 sod samples were randomly taken from each replicate, and the total number of surviving Japanese beetle grubs were recorded for each ft sample. An average of eight Japanese beetle grubs per ft2 was recorded 13 May before treatment.