Prevention of Spotted Lanternfly Infestation in Vineyards Using a Physical Barrier

Progress report for FNE21-993

Project Type: Farmer
Funds awarded in 2021: $14,996.00
Projected End Date: 02/29/2024
Grant Recipient: M&M Vineyards
Region: Northeast
State: Pennsylvania
Project Leader:
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Project Information

Project Objectives:

The proposal seeks to address if a physical barrier would intercept adult SLF migration from the surrounding landscape into our vineyard. Following are the key methods to assess efficacy of the treatment:

  1. In early spring 2021, the number of egg masses per vine will be counted (reflecting 2020 SLF presence) and this will serve as a baseline for year 2022 egg masses counts (reflecting 2021 presence).
  2. The amount of sooty mold on leaves will be recorded on the vines both within and outside of the barrier. similar data during 2020 growing season were collected and will serve as baseline for the intensity of SLF presence in the vineyard in 2021.
  3. The number of dead SLF at the base of the netting wall will be counted regularly. This will provide a metric of how many SLF have been prevented from entering the vineyard.
  4. The number of SLF per vine in the untreated (no barrier) and treated (protected with barrier) areas will be counted throughout the season to assess effectiveness of the barrier.

If successful, this method provides a practical, economical and perhaps the only sustainable agriculture solution currently to prevent SLF damage in vineyards of all sizes.

Introduction:

Spotted lanternfly (SLF), Lycoma delicatula is an invasive insect native to Asia, first discovered in PA in 2014 in Berks County and has now spread to 9 eastern states with additional detections in 5 additional states (attached photos, adult SLF and lifecycle ). SLF falls in Hemipteran insects, meaning it has a piercing-sucking mouthpart, allowing them to drill into phloem of plant to feed directly on sap. SLF has a broad host range feeding on 70+ plant species, including tree-of-heaven, grape, black walnut, red/silver maple, river birch  and sumac (4). Major damages are being noted in vineyards in the northeast region as captured by Paul Vigna (1, see attached, adult SLFs on a grape vine). Feeding damage caused by SLF includes reduced photosynthesis, sap flow, fruit quality, and winter hardiness of the grapevine (H. Leach, personal communication). As SLF feeds, it excretes honeydew, a sugary waste product which can build up on the leaves and cause the growth of sooty mold (attached photo of a grape leaf). This mold acts as a sunblock and can prevent photosynthesis, thereby reducing the energy available for the grapevine. SLF has the potential to greatly impact agriculture, if uncontrolled; this insect could cost the PA state alone $324 million annually and more than 2800 jobs. Many vineyards in eastern PA have incurred substantial vine death and there is no clear long term sustainable solution to curb this pest (1).  PA State Governor and USDA (SCRI CAPS Grant) have allocated $18 million in grants recently for research on SLF that affects the future vitality of the states agriculture industry. Key efforts included in this funding are: quantify impact on at-risk-specialty crops including grapes, conduct fundamental research on pest’s basic biology, ecology, and behavior, develop biological controls contributing to long-term sustainable solutions; deliver management solutions to specialty-crop stakeholders. While research progress has been made on SLF, grape growers are still left with few control techniques apart from the repeated use of insecticides to manage SLF on their farms.

M&M vineyards encountered a major population of SLF in 2020 and in spite of insecticidal sprays; the SLF’s were difficult to control as new populations continuously moved in from the surrounding landscape. In 2020, a small scale study was conducted at Penn State using a 13’ tall insect net wall on one side of a vineyard, covering in netting treated with insecticide (Heather Leach, personal communication, 4). This structure showed promise, reducing SLF populations on the nearby vines by 40.4% throughout the growing season. However, additional height and length was noted as ways to improve efficacy of this technique in the future.

We are proposing to erect a 40’ tall insect net fence around the vineyard on four sides. The top side of the net would be inverted to the outside to create an inverted V arm (2’ long) to create an upside down pocket at the top of the net for SLF to gather after walking up the net. Netting treated with insecticide (long lasting insecticide net, LLIN) will be added to this inverted V pocket at the top in select areas. A small number of vineyards rows (~10%) will be kept outside the nets as negative controls to determine the efficacy of the barrier. SLF studies have shown (personal communication-Heather Leach and Dr. Rajotte, Penn State) that SLF tends to walk upward to reach the top of any object to take the next flight (if it didn’t land on a desirable host tree). Once SLF reaches the top inside of the inverted V section of the net, it will come in contact with the insecticidal netting and die before reaching the vineyard. The number of dead SLF at the base of the wall will also be recorded regularly throughout the growing season.

Most state and federal grants funded are looking for a long-term solutions to the problem, an important goal for overall control of this invasive species. However, grape growers are left with only one effective solution at present: repeated insecticide applications. Frequent use of these broad-spectrum insecticides is not economically or environmentally sustainable and can cause other issues, including killing beneficial insects and flaring secondary pests. SLF is a serious pest of grapevines causing plant health and yield declines, and new management tactics are desperately needed in vineyards to effectively control this pest. This proposed measure could both decrease the use of insecticide applications in vineyards and the number of SLF in the vineyard and suggests a promising new tactic for SLF management in vineyards.

Cooperators

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  • Carrie Brown-Lima (Educator)
  • Cain Hickey - Technical Advisor
  • Amy Korman - Technical Advisor

Research

Materials and methods:

arial view of vineyard

The plan includes erecting 40’ high insect net around the vineyard (2000’ total length). See attached photo of the treated or inside the netting  vine rows and untreated or outside the net vine rows. 52’ long utility poles will be buried 7’ deep in the ground at the periphery of the vineyard 100’ apart. Multiple high tensile strength, 12.5 gauge steel trellis wires will be installed on the poles to hang 17’ wide insect nets with overlapping ends tied to the trellis wires. Top end of the curtain will have an inverted V design to the outside. Two of the four sides will have insecticidal netting (30” wide) running across the length.

  1. Egg masses number per vine comparison in year 2022 among inside (positive control) and outside (negative control) vines will provide the direct evidence of the effectiveness of the netting.
  2. We have collected baseline data on severity of sooty mold on grapevines in 2020 season per vine for 10 vines as in #1 above monthly for August, September and October. The date on sooty molded leaves included coding of 1-5 with 1 being minimum deposit (10 spots or less) and 5 being fully blackened leaves. Similar data will be collected per vine in 2021 during August to October post net installation to measure intensity of SLF presence. Similar observations will also be made within positive and negative vines within the same year giving direct evidence of the effectiveness of the netting.
  3. Direct count of live SLF present for both the positive and negative controls within the same year will be made by selecting 10 vines for 4 rows on the outside (negative control) and 4 adjoining rows on the inside to have direct comparison. SLF are easy to identify compared to other vineyard pests and all vineyard staff are trained on the identification of SLF.
  4. The number of dead SLF at the base of the netting wall will be made on all four sides. Two 25’ sections will be marked on each side and all dead flies will be collected and counted weekly between August and October. This may provide evidence on; 1) how effective the netting is at stopping SLF entry, 2) how effective are insecticidal nets. Comparison will also be made on the four sides to assess the SLF pressure from the tree lines (north and south) verses agriculture fields (east and west).
  5. All data collection will be made by MS (project lead) with the assistance of vineyard staff and project technical support (Heather Leach, Penn State). Ms. Leach will also assist with statistical analysis, comparing the number of SLF on treated vines to the untreated vines using an ANOVA with repeated measures.
  6. The cost of the project will be carefully monitored, including supplies, construction time, and labor estimates. This will be used to help build an economic assessment of the project and allow other growers to evaluate its efficacy both in controlling SLF and its economic feasibility. This information will be shared with other growers from Heather Leach, technical support on the project.
Research results and discussion:

The project started in the spring of 2021 initiating baseline data collection reflecting the presence of spotted lanternfly (Blackening of leaves and trunks/cordons and presence of egg masses) in the vineyard during year 2020 (see Table 1 below) . Three attributes of the SLF presence included, Vine Trunk/Cordon blackening, Egg masses on vines and leaf blackening due to SLF presence and their sugary excretion consequently leading to sooty mold growth blackening vine parts. Data were also collected in the Fall of 2020 counting live SLF on select number of vines per row (Table 1). The installation of netting around the vineyard was completed early August -2021 (see photo under materials and methods). During the months of September and October, 2021, additional data were collected on the control vines which resided outside the nets (Vine Rows 44-48) as well as on the experimental vines which were inside the nets (Vine Rows, 1-43) (Table 1). Additional data collection is pending in the spring of 2022 (egg masses).

Limited data analyses clearly indicates reduced SLF presence inside the net area and reflects clearly the physical barrier preventing migration of SLF into the vineyard. Further inferences would be drawn and explained in the final report,

Table 1: SLF Data on trunk blackening, SLF egg mass count, leaf surface blackening, live SLF presence for two years to compare the impact of physical barrier installed on SLF migration into the vineyard.
Grape Vine Row # Grape Variety Vine Canopy Style Trunk Blackening Score-2021* Trunk Blackening Score-2021** Egg Masse /10 Vines Counted, April-2021*** Egg Masses /10 Vines Counted, April-2022**** Leaf Blackening Score/10 Vines October, 2020# Leaf Blackening Score/10 Vines October, 2021## Live SLF count/10 Vines September 2020### Live SLF count/10 Vines September 2021####
Grape Vine Row #1 Chardonnay Vertical Shoot Position 6 TBD 2 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #2 " " 5 TBD 4 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #3 " " 5 TBD 5 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #4 " " 4 TBD 3 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #5 " " 3 TBD 3 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #6 " " 4 TBD 6 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #7 " " 7 TBD 4 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #8 " " 4 TBD 0 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #9 Souv. Blanc " 9 TBD 12 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #10 Pinot Noir " 10 TBD 6 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #11 Merlot " 14 TBD 10 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #12 Cab Franc " 5 TBD 14 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #13 " " 8 TBD 17 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #14 " " 9 TBD 15 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #15 " " 7 TBD 7 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #16 " " 8 TBD 15 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #17 " " 11 TBD 20 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #18 " " 16 TBD 21 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #19 " " 7 TBD 34 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #20 " " 10 TBD 27 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #21 " " 7 TBD 20 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #22 Riesling " 10 TBD 12 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #23 Vidal Blanc " 8 TBD 5 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #24 " " 6 TBD 9 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #25 " " 6 TBD 9 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #26 " " 5 TBD 5 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #27 " " 5 TBD 6 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #28 " " 4 TBD 3 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #29 " " 7 TBD 1 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #30 " " 6 TBD 5 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #31 " " 9 TBD 5 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #32 Chambourcin " 14 TBD 9 TBD Not Counted Not Counted Not Counted Not Counted
Grape Vine Row #33 " " 10 TBD 11 TBD 9 0 102 0
Grape Vine Row #34 " " 12 TBD 4 TBD 8 0 103 0
Grape Vine Row #35 " " 13 TBD 5 TBD 9 0 78 0
Grape Vine Row #36 " " 16 TBD 15 TBD 11 0 117 0
Grape Vine Row #37 " " 15 TBD 10 TBD 11 0 131 1
Grape Vine Row #38 " " 14 TBD 6 TBD 10 0 133 1
Grape Vine Row #39 " " 13 TBD 9 TBD 15 0 172 1
Grape Vine Row #40 " " 13 TBD 6 TBD 20 0 152 1
Grape Vine Row #41 " " 18 TBD 4 TBD 24 0 140 1
Grape Vine Row #42 " " 18 TBD 7 TBD 29 0 149 0
Grape Vine Row #43 " " 19 TBD 3 TBD 23 0 186 1
Grape Vine Row #44 LaCrescent Double Geneva Curtain 9 TBD 0 TBD 12 6 63 24
Grape Vine Row #45 " " 7 TBD 0 TBD 11 7 50 23
Grape Vine Row #46 " " 9 TBD 1 TBD 9 6 79 29
Grape Vine Row #47 " " 12 TBD 4 TBD 11 7 98 43
Grape Vine Row #48 " " 8 TBD 2 TBD 19 13 125 53
                     
                     

*Trunk blackening score (1X to 5X) depicts extent of shooty mold growth on leaves-the aggregate score reflects a count on 10 vines, 5 end vines on east side and 5 end vines on the west side of each row counted here and in all cases noted below. YR 2021 reflects YEAR 2020 SLF presence. **Year 2022 count reflects 2021 SLF presence-this count is to be determines (TBD) in the spring of 2022.  ***As above, egg masses counted on 5 vines on each side of the rows and the numbers reflect aggregate of 10 vines counted per row in 2021 reflecting SLF activity in 2020. **** 2022 egg masses count reflect 2021 SLF activity and yet to be determined(TBD). # 2020 Leaf Blackening reflects 2020 SLF presence and is again based on 1X to 5X blackening score and is an aggregate reflects total of 10 vines counted as above. ##2021 leaf blackening count reflects 2021 SLF presence. ####2020 Live SLF count  reflects SLF presence in September of that year and is a aggregate of cout on 10 vines for each row. #### 2021 Live SLF count reflects SLF presence in September of 2021 and is an aggregate of 10 vines counted.     

NOT COUNTED: The data for leaf blackening and Live SLF count was only made for vines rows, 33-48 and not counted for rows 1-32.                                                                                                                                                                                                                                                                                              

Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.