Control of grape root borer

FARMER/GROWER GRANT REPORT

1. Project name and contact information
Project title: Control of Grape Root Borer
Project number: FNE05-550
Project contact Name: R. Martin Keen
Organization: Landey Vineyards
Mailing address: 411 South Queen Street
Lancaster, PA 17603-5617
Phone number: (717)394-3893
E-mail: growsaffron@juno.com

2. Goals

Little work has been done on the grape root borer in Pennsylvania. Several methods are available to trap and enumerate the adult male grape root borer with pheromone lures. We have worked with different trapping methods in our vineyard. This project continues two previous SARE grants, FNE03-471 and FNE04-520. Results from 2003 revealed the color of the trap is a significant parameter in the number of moths captured. The standard (yellow with green and white) and green traps were significantly more effective than the white traps. No significant difference was found between the three height treatments used in the study. In 2004 the standard (yellow with green and white) traps were significantly more effective than the green or white traps. The high placement of the traps was significantly better than the medium or low placement in 2004 with the one statistical program, but no significance was found using the other program. The current SARE project will continue to build upon the previous work. A new trap color (all yellow) will be used to ascertain the best possible color. Trap placement will remain the same to check if there is any significant difference. One of the main goals of this project will be to ascertain if mating disruption is possible with high numbers of pheromone traps in a vineyard. Because of the multiple year life cycle (at least three years) of the grape root borer an extended testing period is required. If mating disruption is possible as a control measure, the need for pesticides would be eliminated.

3. Farm Profile

I am a part-time farmer currently farming 5 acres with my brother. The land is rented from our mother. The total size of the present farm is only 7.8 acres, although it has been cultivated by our family for seven generations. There is no house on the premises, only a 40' by 60' tobacco barn. My brother and I first planted wine grapes on the farm in 1974. Today a total of 3.5 acres is planted in wine grapes and includes the French hybrids: seyval, vidal and chambourcin. The vines are grown with unilateral or bilateral cordon training on the bottom wire. A standard three wire system with wires at 36, 54, and 72 inches is used for the trellis. The vines are trained using vertical shoot positioning. Vineyard spacing is 9 foot wide rows with 6 feet between the vines in the row. An area of approximately one half acre is used for the growing and production of grafted vines and other varieties. Since 1989 I have also grown one half acre of saffron on the farm. Currently I am the only commercial grower of saffron in the United States.

The farm is composed entirely of Duffield silt loam with a 0 to 3% slope on the top of a small hill. The location provides excellent air drainage with no frost pockets. The surrounding area is almost entirely in farmland and is located in an agricultural security area. There have been no changes in the operation since the initiation of the SARE project.

4. Participants

The technical advisor for this project is Mark Chien of Pennsylvania State University. Since 1999, Mark has been the wine grape agent for Penn State Cooperative Extension, serving a 15 county region in southeastern Pennsylvania. Another advisor on the project is Dr. Michael Saunders of the entomology department at Pennsylvania State University. One area of his research involves the ecology and pest management of arthropods affecting vineyards and refining existing grape management practices. His extension work covers integrated pest management in viticulture. Dr. Saunders will provide expertise in experimental design and statistical analysis of the data.

A total of 19 vineyard operators and extension personnel located in Pennsylvania, Maryland, New Jersey, New York, Connecticut and Rhode Island agreed to check for the presence of grape root borer in 21 different vineyards.

5. Project activities

The results from the 2003 SARE project (FNE03-471) revealed the color of the trap can be significant in the number of moths captured. A complete statistical analysis of the data from 2003 revealed the standard (yellow with green and white) and green traps were significantly more effective than the white traps. No significant difference was found between the three height treatments used in the study. In 2004 (FNE04-520) the same experimental design was used to check and validate the previous results. A statistical analysis of the 2004 data revealed the standard (yellow with green and white) traps were more effective than the green or white traps. The 2004 data also indicated, with just one method of statistical analysis (AgStats02), the high trap placement is more advantageous. In 2003 and 2004 the white traps were the least effective of the three different colors. In 2005 the white traps were removed from the study at our vineyard and were replaced with a trap that was completely yellow. The standard traps, a portion of which was yellow, were the most effective in capturing moths in the previous years of the study.

The goals were to maximize the capture rate by determining the best color and placement of traps and to ascertain if mating disruption is possible with a high number of traps. The experiment was designed to attempt capture of all male moths with sufficient replicates for statistical analysis. In 2003, 31% of the traps caught no root borers at all and four traps or 5% were responsible for capturing 25% of the moths. Again in 2004, 31% of the traps caught no root borers at all and four traps or 5% were responsible for capturing 20% of the moths. The experimental design from 2003 and 2004 was repeated in 2005 using the same plots and blocks with the traps placed in a new random selection. The variables tested were trap color and placement. A randomized complete block design was developed for each variable. The experimental area covered 80% of the vineyard.

Three different trap colors were selected for the test in 2005, yellow, standard (yellow with green and white) and green. The standard and green plastic universal moth traps available from Great Lakes IPM (Vestaburg, Michigan)were utilized. These were the same traps used in 2003 and 2004. The all yellow traps were purchased from Advanced Pheromone Technologies, Inc., Marylhurst, Oregon. A total of 81 traps were placed in the vineyard or 27 of each color: yellow, standard and green.

The vineyard was divided into 27 blocks of 72 feet by 54 feet or 3888 square feet per block. Each block was divided into three plots of 18 feet by 72 feet or 1296 square feet per plot. A trap was suspended on the trellis at the center of each plot. Every block received the three different colors. The color of each trap placed in the plots of each block was selected using a ten thousand random digit table.

Three different trap height placements were selected for testing in 2005. The same heights used in 2003 and 2004 were repeated. Traps were placed 18 inches above the ground or below the vine canopy, 44 inches above the ground or in the middle of the canopy close to the fruiting zone and 70 inches above the ground or at the top of the vine canopy. The distance from ground level was based on the position of the pheromone lure.

For trap height the vineyard was divided into 9 blocks of 162 feet by 72 feet or 11,664 square feet per block. Each block was divided into three plots of 72 feet by 54 feet or 3888 square feet per plot. Each plot for the trap height experiment was the same as a block for trap color. Within each plot for trap height, the three traps all received the same height. For each of the three trap heights there were 27 replicates, three in each plot. The height of the traps in the plots of each block was selected using a ten thousand random digit table.

The traps were placed in the vineyard on June 17th according to the experimental design. A 10% DDVP toxicant insecticide PVC tape measuring 1 inch by 4 inches was placed inside each trap to kill any moths that entered. A pheromone lure for grape root borer was placed in the lure holder of each trap. The traps were checked every three or four days or twice a week from June 17th until September 3rd with the moths captured recorded on data sheets.

A total of 19 cooperators agreed to place 28 traps in 21 different vineyards in six states. Each cooperator was sent instructions on the use of the pheromone moth trap and asked to place the trap in the vineyard between June 18th and June 20th. The traps were to be checked weekly until the end of August and all moths recorded.

A survey was sent to each cooperator asking about their vineyard operation. Questions included location, varieties planted, rootstocks used, age of vines, acres of each variety, training system, irrigation, mulching, under the vine maintenance, row middle maintenance, proximity of wild vines (wooded area adjacent to vineyard), grape root borer monitoring, and use of any control method for grape root borer.

6. Results

In our vineyard the first male grape root borer moths were recorded on July 5th (2 moths) and the last August 20th (2 moths), with the highest catch on July 16th with 78 moths. A total of 266 moths were captured in 2005, an 85% increase from the total captured (144 moths) in 2004. In 2003 a total of 224 male grape root borer moths were captured. This variability in the total number of male grape root borers captured each year is not unexpected. There is a very high mortality of eggs and newly hatched larvae that can vary significantly from year to year depending on many factors such as the weather and the presence of predators during egg development and hatching. In the northern region of the grape root borer range (Pennsylvania) most of the larvae have a three year life cycle. In 2005 the majority of moths captured would have come from eggs laid before the initiation of the project in 2003.

Table 1. Major Catch Dates for 2005

Date Total moths captured
7-5 2
7-9 10
7-12 15
7-16 78
7-19 54
7-23 45
7-26 25
7-30 11
8-2 8
8-6 8
8-9 8

The initiation of moth emergence, date of highest catch and the end of moth emergence also varies from year to year.

Statistical analysis was performed on the data with two different programs. The first was the agricultural statistics analysis program (AgStats02) provided by the Pacific Northwest Conservation Tillage Systems Information Source at http://yolo.usda-ars.orst.edu/steep/AgStatsweb/. This program allows up to 16 treatments and 16 replicates and performs an analysis of variance. The level of significance can be selected at 1%, 5%, 10% or 20%. All data entered with this program utilized the randomized complete block design option. The other statistical program was SAS/STAT from the SAS Institute performing an analysis of variance and Tukey's studentized range (hsd) test. This test is also called the honestly significant difference (hsd) procedure.

The height treatment data in the statistical programs has been entered as low (18 inches above ground level), medium (44 inches above ground level) and high (70 inches above ground level).

Using the Agstats02 with nine replicates, the high placement at 70” and the medium placement at 44” were significantly better than the low at a 5% level of significance.

With the Tukey's studentized range (hsd) test using 27 replicates, a significant difference was found in the height treatments. The high placement was significantly better than the low placement

Color treatments are entered in the statistical programs as yellow, standard (yellow with green and white) and green.

Table 5. Color Treatments 2005

yellow 98 moths
standard 95 moths
green 73 moths

The experimental design for each color treatment (yellow, standard and white) contained 27 replicates. Unfortunately the AgStats02 program allows only 16 replicates. To run this program the three replicates of each color in each height block were combined. The three treatments (yellow, standard and white) were entered with nine replications. At a 5% level of significance, no significant difference was found in the 2005 color treatments with the AgStats02 program.
With the Tukey's studentized range (hsd) test using 27 replicates, no significant differences were found in the color treatments in 2005 at a 5% level of significance.

An analysis of variance (AgStats02) for the combined treatments (height and color)was performed. For this statistical analysis nine treatments were entered with nine replications. Within each height treatment block (162 ft. by 72 ft.) there are all nine possible combinations of height and color treatments. At a 5% level of significance the high standard and high yellow are significantly more effective than the three color treatments at the low trap placement.

Based on statistical analysis in 2005, the height treatments are significant. The high placement of 70 inches was significantly better than the low placement of 18 inches in both statistical programs. In previous years the the height treatments were rarely significant. Only the AgStats02 program in 2004 showed any significance with the high better than the medium or low, although each year the high traps have caught the greatest number of moths.

The color treatments of standard, yellow and green had no statistical significance in 2005. In the previous two years the color was always significant. The only difference in 2005 was the removal of the all white traps and substituting them with all yellow traps. The white traps had consistently caught the lowest number of moths and were the poorest statistically. In 2003 and 2004 the standard (yellow with green and white) traps captured the greatest number of moths and were usually the best statistically. The all yellow traps caught the greatest number of moths in 2005 but the yellow and standard traps caught almost identical numbers of male grape root borers. The presence of the color yellow in a trap is obviously a very important parameter.

Three varieties of French hybrid grapes; seyval, vidal and chambourcin are planted in the vineyard. The experimental design was developed primarily to test if adult male grape root borer moths would have a preference for different pheromone traps based on color and location. The initial plan called for an attempt to determine if grape root borers have a preference among the three varieties planted in our vineyard. Unfortunately the experimental design only allows a comparison to be made between seyval and vidal.

In an analysis of variance (AgStats02) based on variety preference, two treatments (seyval and vidal) were entered with eight replicates. No significant difference was found between the two varieties even at a 20% level of significance. The same result occurred in 2003 and 2004.

A total of 28 universal moth traps were sent to 19 cooperators and placed in 21 different vineyards in six states. Traps were to placed in four vineyards in Maryland, ten in Pennsylvania, three in New Jersey, two in New York, one in Connecticut and one in Rhode Island. Five cooperators did not respond or send in any data from their trap.

One of the main reasons for the survey was to initiate work on establishing the range of grape root borer in the northeastern United States. Six locations caught no grape root borer, two in New York, one in Connecticut, one in Rhode Island, one in Pennsylvania and one in New Jersey. The two vineyards (45 and 53 acres) in New York are located in Suffolk County on the north fork of Long Island. Both vineyards are composed of older (15 and 25 years) vinifera vines and had woodlands adjacent (30 and 25 feet) to the vineyard. A wooded area close to the vineyard would most likely contain wild grapevines and could be a reservoir for grape root borer. If grape root borer was present in the area these two vineyards should have been infested.

The Rhode Island vineyard (35 acres) is located in Newport County and is composed of older (6 to 30 years) vinifera and French hybrid vines. This location also has woodlands adjacent (20 to 100 feet) to the vineyard and should have been infested if grape root borer was present.

A vineyard (20 acres) in Litchfield County in western Connecticut also had no grape root borer present. The vineyard is composed of 15 year old vinifera and French hybrid vines and is adjacent (30 feet) to a wooded area.

One location in Pennsylvania was negative for grape root borer. The vineyard (8 acres) is located in Mercer County in the northwestern part of the state and was planted in French hybrid and vinifera grapes 5 years ago. A wooded area is about 200 feet from the vineyard. The Lake Erie grape belt in Ohio and Pennsylvania is approximately 60 miles to the north and is known to be grape root borer free.

A vineyard in Warren County, New Jersey reported no grape root borer. This vineyard (6 acres) was planted in vinifera and French hybrid grapes just 2 years previously. A wooded area is located 150 feet from one side of the vineyard. Another, much older vineyard (25 years) in the area ( about two miles away) tested positive for grape root borer in this study.

A total of ten locations tested positive for grape root borer, five in Pennsylvania, three in Maryland and two in New Jersey. In New Jersey, one vineyard was located in Warren County. It has 3 acres of 25 year old hybrids and 17 acres of 5 year old vines. Herbicide is used to keep the area under the vines weed free The distance to the nearest wooded area was 300 yards. A total of 55 male grape root borer were captured. The other New Jersey vineyard is located in Atlantic County and has a total of 25 acres of vines with vinifera, hybrid and native varieties. All vines are between 3 and 5 years old. The area beneath the vines is maintained with herbicides and the row middles have a permanent cover crop. A wooded area is adjacent to the vineyard. This vineyard was previously checked for grape root borer and they were present as early as 2002 when the vines would have been only 2 years of age. Lorsban is used in the vineyard as a control method for grape root borer. Besides the trap that was supplied in this study, the vineyardist also placed two other traps. All three traps had a bimodal catch pattern, with two peaks of captures. The first with fewer moths was on July 19th and the second larger catch was on August 9th. The trap that was supplied in this study was placed in hybrid vines and caught a total of 135 male moths. Another trap was placed 1000 feet away in a grafted vinifera block and captured 83 moths. Their third trap was placed in a grafted vinifera vineyard ½ mile from the other two traps. It captured a total of 272 moths.

All of the traps in three different Maryland counties captured grape root borer. One trap was located in Harford County in a 3 year old vineyard of grafted hybrid vines. Herbicides are used to maintain the area under the vines and the row middles are covered in a permanent cover crop. A wooded area is located 100 feet from the vineyard. A total of 76 grape root borers were captured. Another vineyard is located in Baltimore County.
This vineyard has 16 acres of French hybrids and vinifera, ranging in age from 1 to 30 years of age. The area under the vines is maintained with herbicides and cultivation. Row middles are maintained with mixed cultivation and cover crops. Wooded areas are located 150 feet from the vineyard. A total of 55 moths were trapped in this vineyard with the highest catch on August 9th. The third Maryland vineyard is located in Frederick County and contains 14 acres of vinifera and French hybrid vines ranging in age from 4 to 25 years old. In this vineyard the area under the vines is maintained with herbicides and the row middles have a permanent cover crop or sod. A wooded area is located 100 feet from the vineyard. A total of 94 grape root borers were trapped with the highest catch on July 20th.

Five vineyards in Pennsylvania were positive for grape root borer, two in Lancaster County, two in Berks County and one in Chester County, all in the southeastern part of the state. The vineyard in Chester County has 3 acres of grafted vinifera that are 7 years old. The area under the vines is maintained with herbicides and the row middles have a permanent cover crop. A hedge row with trees is adjacent to the vineyard. A total of 94 grape root borers were captured, with the highest count on July 19th. One vineyard in Berks County has 6 acres of grafted vinifera and French hybrids, ranging in age from 1 to 5 years old. The area under the vines is maintained with herbicides and cultivated with a Weed Badger. The row middles are covered with a permanent cover crop. A wooded area is located just 20 feet from the vineyard. A total of 35 grape root borers were captured. The other Berks County vineyard has 4 acres of vinifera and hybrids that are 8 years old. Herbicides are used under the row for weed control and the row middles are covered with a permanent sod. Wooded areas are found 75 and 100 feet from the vineyard. A total of 43 grape root borers were captured at this vineyard with the highest catch on July 26th.

The one Lancaster County vineyard has 6 acres of grafted vinifera ranging in age from 3 to 7 years old. The area under the vines is maintained with herbicides and the row middles have a permanent sod. The nearest wooded area is ¾ of a mile away and this vineyard is located 9/10 of a mile from our vineyard. A total of 25 grape root borers were captured and the highest catch was recorded on July 16th. The other Lancaster County vineyard has an area of 5 acres and contains French hybrids and some grafted vinifera ranging in age up to 32 years old. Herbicides are used to maintain the area under the vines and the row middles are covered in permanent sod. A majority of the vineyard is surrounded by wooded areas 10 to 20 feet away. Because of the inability to interest enough vineyardists to participate in this survey eight traps were placed in this vineyard. Four traps were placed about 9 feet apart in a square pattern in one section of the vineyard that appeared to be heavily infested with grape root borers. The vines (vidal variety) were very low in vigor and all the traps were readily visible with no grape foliage close to the traps. The other four traps were placed in the same pattern about 600 feet away in another portion of the vineyard where the vines (foch variety) were more vigorous and the traps were not readily visible because of the grape foliage. In the section of vineyard with low vigor vines (vidal) a total of 232 moths were captured and in the area with more vigorous vines (foch), 293 moths were captured. A total of 525 grape root borers were captured with the highest count on July 16th.

The survey of six northeastern states for grape root borer revealed some areas are most likely root borer free. Based on this survey and other studies the northern boundary of the grape root borer in the northeastern United States is most likely Interstate 80 in Pennsylvania and New Jersey. More work will have to be done to determine the exact range. All the vineyards tested south of Interstate 80 had grape root borer present except one. This vineyard in Warren County, New Jersey was only three years old and will most likely have grape root borer present in the near future. Another vineyard in Warren County just over two miles away, but with three acres of 25 year old vines, tested positive. The survey was meant to find any trends in the distribution and severity of grape root borer. No trends were apparent, only that if grape root borer is present in the area the moths will find the vineyard within a few years. The lack of wild grapevines in the immediate area may slow the introduction of grape root borer but it does not prevent it. One vineyard in Lancaster County, Pennsylvania is ¾ of a mile from the nearest wooded area and was first planted seven years previously, but 25 moths were captured. This was the lowest total catch. The presence of wooded areas with wild grapevines probably increases the rate at which a vineyard will become infested. A 2 acre vineyard in Harford County, Maryland that was planted just three years previously caught a total of 76 moths. A wooded area was located 100 feet from the vineyard. This is a high count for such a young vineyard. In Atlantic County, New Jersey, a vineyard with 3 to 5 year old vines caught 135 moths. Again wooded areas were adjacent to the vineyard. As the vineyard ages the number of grape root borers present increases. In Lancaster County, Pennsylvania a seven year old vineyard captured 25 moths. Our own vineyard, first planted 31 years ago had grape root borers detected seven years later in 1981. For the last three years during this project we have captured an average of 211 per year with 81 traps. Another vineyard in Lancaster County that was first planted 32 years ago caught 525 moths with 8 traps. A majority of this vineyard is surrounded by trees with numerous wild grapevines just 10 to 20 feet from the vineyard.
Cultural practices seemed to have no effect on the presence or severity of grape root borer infestation in the vineyards surveyed.

7. Conditions

N/A

8. Economics

Although the project was not structured for economic analysis some trends are apparent. Since the introduction of universal moth traps to the vineyard, production has increased. Many other variables, such as weather or disease pressure, could account for this increase. instead of the presence of moth traps. With the increase in production, total farm income has also increased. The production of chambourcin, our most valuable variety, peaked in 1996 at 5.5 tons total production. By 2002 when two universal moth traps were placed in the vineyard , production had declined to 1.4 tons. Over the next two years, when 81 traps were in the vineyard each year, production increased 184% to 3.97 tons. In 2005 the production of chambourcin decreased by 6.8% from the previous year. This decrease is not substantial and could be attributed to numerous factors. The production of vidal has increased each year since the project started.

9. Assessment

Results from 2005 revealed the placement of the traps can be significant. Both statistical tests found the height to be significant. With AgStats02, the high and medium placement were significantly better than the low placement. The high placement was significantly better than the low placement with Tukey's studentized range (hsd) test. Each year the high traps have captured the greatest number of moths, but this was the first year with a truly significant difference. Testing will continue to verify the results from 2005.

In 2005 no significant difference was found in the color treatments. Previously in 2003 and 2004 the color treatments had shown a statistical significance each year. The white traps had consistently captured the lowest number of moths and had been the least effective statistically. With the removal of the white traps from the experiment no significant differences were found in the color treatments. The standard color traps and the all yellow traps caught almost identical numbers of moths. In terms of color, the presence of yellow seems to be the most important parameter. Testing will continue next year with the same colors to verify the results from 2005.

Distribution of the grape root borer in a small area can be very random. In the experimental test area of 2.41 acres, there were plots with no root borers and other areas of higher concentrations. In both 2003 and 2004, 25 traps or 31% caught no root borers during the 2.5 months of trapping. The number of traps catching no root borers in 2005 decreased to just 7 or 9% of the total traps. There is no apparent reason for this change other than the removal of white traps from the experiment.

Plots with high concentrations of captured moths continues to decrease. In 2003, 4 traps or 5% captured 25% of the moths. The four highest trap catches in 2003 were 17, 15, 14 and 10. In 2004, 4 traps or 5% captured 20% of the moths and the two highest trap counts were 8, followed by 7 and 6. Four traps or 5% captured 16% of the moths in 2005 and the four highest trap catches were 14, 11, 9 and 8. Over the three years of testing it would appear the moths are more diffuse throughout the vineyard.

10. Adoption

The results after three years of the project are still encouraging. The yellow and standard traps continue to capture the most moths, but not in statistically significant numbers. Yellow still appears to be a very significant parameter in the capture of grape root borer.
An all yellow trap was first used in 2005 and testing will continue on the significance of color to verify previous results.

With the removal of white traps from the experiment, the height placement was statistically significant in 2005. The high placement was significantly better than the low placement in both statistical programs. Testing will continue with all three height placements to verify the results from 2005.

Mating disruption still appears to be a possibility, although the total number of moths captured increased in 2005. In the 2003 SARE project, 224 male moths were captured.
The following year in 2004, 144 moths were captured, a 36 % decrease. The total number of moths captured, increased to 266 in 2005. An increase in the number of male moths captured does not mean mating disruption is unattainable. The grape root borer in the northern portion of its range (Pennsylvania, New Jersey and Maryland) can have a three year larval life cycle. A majority of the moths captured in 2005 could be from eggs laid in 2002 before the current SARE project started. The production of grapes indicates trapping has been helpful in reducing the total number of grape root borers in the vineyard. Production and vigor of the vines has increased during the project. Chambourcin grape production went from 1.4 tons in 2002 to 3.7 tons in 2005 and vidal increased from 3.9 tons to 9.2 tons in the same time period. With a three year larval lifespan, if mating disruption is possible, reductions in the number of grape root borers captured should be seen in future years. Just the increase in production has shown the trapping to be beneficial.

11. Outreach

A half hour power point presentation on the 2003, 2004 and 2005 SARE projects was presented at the 2006 Grape Expectations Symposium on March 11, 2006 in Jamesburg, New Jersey. Approximately 80 people attended the talk. To date, I have been unable to be included in any other program. During the summer I will attempt to give presentations at other grape meetings and plans are underway to give short 15 minute presentations at local meetings through the extension agent. If this not possible I may put together my own program in southeastern Pennsylvania on grape root borer.

12. Report Summary

Grape root borer is one of the most serious insect pests of grapes in the eastern United States. The goal of this project is to find a sustainable method of control using pheromone traps. A total of 81 traps were placed in the experimental area of 2.41 acres in the three acre vineyard using a randomized complete block design. Three different colors (standard-yellow with green and white, all green and all white) of traps placed at three different heights were located in the vineyard in 2003 and 2004. The standard (yellow with green and white) traps captured the greatest number of moths and were usually the best statistically in both 2003 and 2004. The white traps had consistently caught the lowest number of moths and were the poorest statistically. With the removal of the all white traps and the addition of all yellow traps, no statistical significance was found in the color treatments in 2005. The all yellow traps caught the greatest number of moths in 2005 but the yellow and standard traps caught almost identical numbers. The presence of the color yellow in a trap is obviously of primary importance.

Based on statistical analysis in 2005, the height treatments are significant. The high placement of 70 inches was significantly better than the low placement of 18 inches in both statistical programs. In previous years the the height treatments were rarely significant. Only the AgStats02 program in 2004 showed any significance with the high better than the medium or low, although each year the high traps have caught the greatest number of moths. After the presence of a yellow color in the traps, the high placement of 70 inches could be considered to be of secondary importance.

Mating disruption still appears to be a possibility, although the total number of moths captured increased in 2005. An increase in the number of male moths captured does not mean mating disruption is unattainable. The grape root borer in the northern portion of its range (Pennsylvania, New Jersey and Maryland) can have a three year larval life cycle. A majority of the moths captured in 2005 could be from eggs laid in 2002 before the current SARE project started. The production of grapes indicates trapping has been helpful in reducing the total number of grape root borers in the vineyard. Production and vigor of the vines has increased during the project. With a three year larval lifespan, if mating disruption is possible, reductions in the number of grape root borers captured should be seen in future years. Just the increase in production has shown the trapping to be beneficial.

The survey of six northeastern states for grape root borer revealed some areas are most likely root borer free. Based on this survey and other studies the northern boundary of the grape root borer in the northeastern United States is most likely Interstate 80 in Pennsylvania and New Jersey. More work will have to be done to determine the exact range. The survey was meant to find any trends in the distribution and severity of grape root borer. No trends were apparent, only that if grape root borer is present in the area the moths will find the vineyard within a few years. The lack of wild grapevines in the immediate area may slow the introduction of grape root borer but it does not prevent it. The presence of wooded areas with wild grapevines probably increases the rate at which a vineyard will become infested. As the vineyard ages the number of grape root borers present increases. Cultural practices seemed to have no effect on the presence or severity of grape root borer infestation in the vineyards surveyed.

R. Martin Keen
May 9, 2006

A copy of the complete final report containing data tables can be obtained by contacting the Northeast SARE office in Burlington.