Sunflower - Sunflower Beetle

plants. Determine the average number of adults and/or larvae per plant. To determinepercent defoliation of plants, examine 100 plants per sampling site for a total of 500plants.Adults attack early in the season, defoliating seedlings. One adult per plant is consideredto be economic. Later the larval stage feeds on larger plants. Fifteen larvae per plant or25 percent defoliation would justify an insecticide application. Alternatively, use thetable below to determine the potential yield loss from the observed level of defoliationEstimated % yield reduction from sunflower defoliation occurring at various growthstages (From North Dakota State University Extension Bulletin 25)Percent Defoliation10 20 30 40 50 60 70 80 90 100Growth StageExpected percent yield lossV-4 to V-5 0 1 2 2 4 4 5 9 14 21V-9 to V-11 0 2 3 4 5 5 7 11 17 24R-1 2 4 6 6 7 9 16 24 34 47R-3 2 8 15 19 24 32 44 59 78 99R-5 1 3 7 10 16 25 37 49 67 90R-7 0 1 3 7 10 13 16 18 20 22R-8 0 1 2 3 5 7 8 9 10 11ai/acre/crop. Do not graze or feed treated forageProduct list for Sunflower BeetlePesticideProduct/Acre (Fl oz. or oz. Preharvest Interval, remarksproduct)Asana XL R,1 2.9 - 5.8 28 days. Do not feed forage or fodder tolivestockExtremely Hazardous to Bees!Baythroid XL R,1 0.8 – 1.6 30 days. Extremely Hazardous to Bees!carbaryl 1,2 See labels 60 days. 30 days to graze or forage. ExtremelyHazardous to Bees!chlorpyrifos 4E R1,2 16 - 24 42 days. Do not graze. Up to 2 lb preplant. Up ttotal AI/yr. Extremely Hazardous to Bees!Delta Gold R,1 1.0 – 1.5 21 days to harvest. Do not apply more than 0.04livestock. Extremely Hazardous to Bees!Furadan 4F R4-8 (foliar)28 days. Apply only before bloom. ExtremelyHazardous to Bees!2.5-5.0 oz./1000 row ft