Efficacy of Insecticides Applied Curatively Against Annual Bluegrass Weevils, Golf Course Fairway, 1993

Ethoprop (Mocap 10G), acephate (Orthene 75SP), trichlorfon (Proxol 80SP), or bendiocarb (Turcam 76WP or 2.5G) was applied in small plots on a golf course fairway on 17 May to control annual bluegrass weevil larvae. Plots were 1.8 × 1.8 m, replicated 5 times in a CRD and were established on a golf course fairway in Harrison, NY—annual bluegrass (30%), creeping bentgrass (70%), maintained at 1.2 cm. All applications were made by hand—liquid formulations were diluted in 2 liters water and applied with watering cans, granular formulations were applied using glass jars with perforated lids. Approximately half the material was applied in one direction, and the remaining half was applied in the perpendicular direction. All materials except Orthene were applied and watered in with 0.5 cm irrigation, and then the Orthene plots were applied. No further irrigation was applied following the Orthene applications. Product efficacy was evaluated on 21 Jun by removing 12 soil cores (5.7 cm diam, 4 cm deep) from each plot, al least 0.5 m from the edge. Insect counts were made by combining totals from 3 plugs per recorded observation (4 observations per plot, 20 observations per treatment). At the time of sampling, the population was 4% 3rd instar, 4% 4th instar, 36% 5th instar, 28% pupae, and 28% adults.