Fall Control of Oriental Beetle Grubs with Experimental and Labeled Insecticides and Entomogenous Nematodes on a Golf Course, 1987

Abstract

Abstract Four insecticides and 1 species of entomogenous nematode were applied to a fairway at Fresh Meadow Country Club, Great Neck, Long Island, N.Y., on 12 Aug for control of Oriental beetle grubs. The fairway consisted of Kentucky bluegrass (40%), annual bluegrass (40%), bentgrass (15%), and braoadleaf weeds (<5%). The experimental design was a randomized complete block with 4 replications. Individual plots were 10 × 10 ft. Granular materials were applied with a precalibrated Candy 2.5 spreader. Liquid materials were measured in the laboratory and applied in 2 directions within each plot with 11.4 liters (3 gal) of water through a watering can. At treatment time (12 Aug) the following environmental conditions existed: air temperature, 84°F; soil temperature, 66°F (1 inch), 64°F (3 inches); soil pH 6.2; water pH 6.65; soil moisture, 20.3%; soil texture, 6.9% coarse sand, 48.8% medium sand, 30.2% fine sand, 9.0% very fine sand, and 4.9% silt and clay; thatch, dense, >0.5 inches. Following treatment, the plots received 0.5 inches of irrigation by sprinkler system. The nematodes, Heterorhahditis sp. (strain HP 88), were applied on 20 Aug at a rate of 5 billion/ acre in 5 liters of water through a sprinkling can to the center 4 sq ft of each plot. The nematode application site was immediately watered in by hand with additional water for a total of 11.4 liters. At this time air temperature was 82°F and soil temperature (1 inch) was 79°F. Posttreatment counts were taken on 21 Sep by cutting a 1- × 3-ft strip lengthwise through the middle of each plot by hand and examining the sod and underlying soil for grubs. A 3-sq-ft sample of sod was examined in each plot, and the surviving grubs were counted. Grub species identifications were made in the field. At this time oriental beetle grubs were 80% third instars and 20% second instars. Only the high rate of Sevin SL significantly reduced Oriental beetle grubs at this site. No phytotoxicity was seen in any of the plots.