Control Methods

Burial of pupae

If pupae are buried after they form at or near the soil surface, the number of adult moths can be reduced. The adult moths are unable to penetrate the added soil layer. In a Missouri experiment, soil was thrown against vines in July, 6 to 10 inches deep and 2 feet across. This resulted in an 85% reduction in adults. In a laboratory experiment, 5 inches of soil resulted in a mortality rate of 97% and 7.5 inches of soil gave a 100% mortality rate. 1 In Arkansas, 4 to 5 inches soil mounded on one date resulted in an 89% reduction of adults. Soil mounded at the same depth ten days later in another test area resulted in a 100% reduction of adults. 2 For soil mounding to work the timing is critical. The soil must be placed after the majority of the pupae have formed and before the adult moths emerge.

Insecticides

The restricted use pesticide Lorsban® 4E (chlorpyrifos) has been used to control grape root borer. Lorsban® Advanced and Lorsban® 75WG are also labeled for use on grape root borer. Lorsban® 75WG is not a restricted use pesticide, while Lorsban® Advanced is a restricted use pesticide. The timing for application of Lorsban® to the soil surface is critical. It is effective against newly hatched larvae as they enter the soil, but not against established larvae in the roots. In tests done in Georgia, Lorsban® was effective in greatly reducing the number of newly hatched larvae in the first four inches of soil. Lorsban® does break down in the soil. After 3 weeks, the amount of Lorsban® was reduced by half. 3 Label instructions say to apply just before the pest emerges from the soil. Lorsban® cannot be used for grape root borer control in Mississippi.

Lorsban® 4E label (PDF)
Lorsban® 75WG label (PDF)
Lorsban® Advanced label (PDF)

Pheromones

With the introduction of the 99:1 blend of EZ:ZZ, the potential for mating disruption was thought to be significant. Numerous studies were initiated in states with high grape root borer populations. Mating disruption studies were done in Ohio (1989), 4 Florida (1991) 5 and Arkansas (1991) 6. The pheromone was dispensed by rope or twist ties at a density of 100 per acre in each study. In these studies the pheromone twist ties were only placed in the test vineyards for one or two years. Success was measured either by counting pupal cases under the vines or moths captured in a few white wing traps containing pheromone lures. A reduction in pupal cases or in male moths captured in the test vineyard traps versus the control was used to determine success.

Only the rubber septa form of the grape root borer pheromone is currently available to the commercial grape grower. Each rubber septa contains 1 milligram of the EZ:ZZ pheromone blend. These rubber septa are used in various types of traps to capture male moths. The amount of pheromones in the twist ties used in the previous studies was 40 times the amount in the rubber septa.

In our vineyard from 2003 through 2008, traps with a rubber septa were placed at a density of 33 per acre. From 2009 through 2013, traps with a rubber septa were placed at a density of 11 per acre. During the period of 2003 through 2013, no significant reduction in the number of male moths captured was seen. Total captures of male moths varied from 144 to 525, with a mean of 347 per year in our 3.4 acre vineyard or (116) per acre. Total male captures are much higher in Southern vineyards. In North Carolina a 0.82 acre vineyard captured 950 males in one year, while other vineyards captured between 188 to 2812 per acre. 7 8 Of course the presence of high numbers of traps in our vineyard might have prevented even greater numbers of grape root borers.

In 2011 the use of a pheromone system marketed as Isomate® GRB (Pacific Biocontrol Corporation) was approved for controlling grape root borer. The pheromones in Isomate® GRB are based on those secreted by the female European leopard moth (Zeuzera pyrina L.)and currant clearwing (Synanthedon tipuliformis Clerck), not the grape root borer. Active ingredients are E,Z-2,13-octadecadien-1-ol acetate or EZ and E,Z-3,13-octadecadien-1-ol acetate or EZ-3 in a ratio of 95:5. The major pheromone for the grape root borer, European leopard moth and currant clearwing is the same but the secondary compound is different. High concentrations of Isomate® GRB are meant to confuse the male grape root borers. The product was initially marketed in Europe for controlling leopard moth and currant clearwing with the name Isonet® Z. The total amount of the EZ:EZ-3 pheromone mixture is lower in a Isonet® Z twist tie (70 mg) than in the Isomate® GRB twist tie (80 mg).

In Florida during 2003 and 2004, Isonet® Z twist ties were placed in four vineyards at a rate of 257 per acre. The Isonet® Z twist ties contain 70 times more pheromones than the standard rubber septa used to monitor grape root borer populations. Two wing type sticky traps (color not reported) with grape root borer pheromone lures were placed in each treatment. These traps captured no male grape root borers and the use of Isonet® Z was deemed a success because of total trap shutdown. 9 The authors of the study however did state that “trap shutdown alone does not prove that mating disruption has occurred.” The current recommended labeled amount of twist ties is 100 per acre.

Twist tie & rubber septa
Isonet® Z brochure (PDF)
Isomate® GRB label (PDF)

  1. Sarai, D. D. 1969 Effect of burial of grape root borer pupae on adult emergence. J Econ. Entomol. 62:1507-1508.↩︎

  2. Wylie, W. D. 1972. Grape root borer research. Proc. Arkansas State Hort. Soc. 93:94-95.↩︎

  3. All, J. N., J. D. Dutcher, M.C. Saunders, and U.E. Brady 1985. Prevention strategies for grape root borer (Lepidoptera: Sesiidae) infestions in Concord grape vineyards. J. Econ. Entomol. 78:666-670.↩︎

  4. Williams, R. N., and J. L. W. Keularts. 1989. Occurrence and control of Vitacea polistiformis (Harris) (Lepidopter: Sesiidae) in Ohio vineyards. Ohio J. Sci. 89(2):4.↩︎

  5. Webb, S. E. 1991. Management of grape root borer in Florida with a pheromone. Proc. Fla. State Hort. Soc. 104:3-5.↩︎

  6. Johnson, Donn T., Barbara A. Lewis, and J. Wendell Snow. 1991. Control of grape root borer (Lepidoptera: Sesiidae) by mating disruption with two synthetic sex pheromone compounds. Environ. Entomol. 20(3): 930-934.↩︎

  7. Pritchard, P. M. 2004. Reproductive capacity of grape root borer, Vitacea polistiformis (Harris), and Implications for pheromone based management. Ph. D. dissertation, North Carolina State University, Raleigh.↩︎

  8. Pearson, G. A. 1992. Pheromone effects on mating success and female behavior in the grape root borer. Thesis, North Carolina State University, Raleigh. Of course the presence of high numbers of traps in our vineyard might have prevented even greater numbers of grape root borers.↩︎

  9. Weihman, S. W., and O.E. Liburd. 2006. Mating disruption and attract-and-kill as reduced-risk strategies for control of grape root borer Vitacea polistiformis (Lepidopter: Sesiidae) in Florida vineyards. Fla. Entomol. 89(2): 245-250.↩︎