Bringing IPM and Natural Enemies Back to the Orchard Post-BMSB

View the project final report

• 2014 annual report

Commodities

• Fruits: apples, peaches, general tree fruits

Practices

• Crop Production: application rate management
• Education and Training: demonstration, extension, on-farm/ranch research
• Farm Business Management: budgets/cost and returns
• Pest Management: biological control, chemical control, cultural control, economic threshold, field monitoring/scouting, integrated pest management, mating disruption, sanitation, traps

The invasive brown marmorated stink bug (BMSB) has disrupted long-standing tree fruit IPM programs with growers drastically changing their management practices to combat the threat posed by this invasive pest. BMSB has over 100 known hosts, including peach and apple, where damage can occur season-long by adult and juvenile stink bugs, making it a key fruit pest in the Northeast. Current management tools for BMSB rely exclusively on weekly season-long applications of broad-spectrum insecticides that are costly, risk pest resistance, kill natural enemies and pollinators, cause secondary pest outbreaks, and may have negative impacts on water quality and soil compaction. This radical shift in pest management practices away from IPM programs is neither economically or environmentally sustainable. Thus, tree fruit growers are eager to adopt new tactics to reduce insecticide inputs for BMSB management.

 Building on our previous work in peach, we will expand our systems-level approach utilizing border sprays, coupled with standard IPM practices, to manage BMSB and other key orchard pests into apples. This approach can reduce insecticide use by 75%, causing a direct decrease in grower production costs. We will compare monitoring methods for management decisions and measure impact on natural enemies and secondary pests. This will be accomplished in commercial peach with an increased focus on natural enemies and expanding to apple orchards with growers who have expressed an immediate need for sustainable BMSB management strategies. We will integrate traditional extension outlets with a field day and a demonstrative educational video for growers.

Background

The invasive brown marmorated stink bug (BMSB) has proven to be one of the most devastating pests of Northeastern agriculture. Since its introduction in mid-1990’s, BMSB is now present in 40 states (Hoebeke and Carter, 2003; www.stopBMSB.org). All mobile stages feed by sucking out plant fluids, which results in “corked, deformed fruit” (McPherson and McPherson, 2000). Peach is a preferred host, supporting populations from mid-late May through harvest. Apples are colonized in mid-late summer and feed through harvest when population densities are greatest (Nielsen and Hamilton, 2009). BMSB constantly disperses between wild hosts and crops causing repeated surges in BMSB abundance within crop fields, particularly along crop perimeters. BMSB’s mobile behavior and the short residual period of effective insecticides require frequent pesticide applications in orchards.

Agricultural production is a major commodity for New Jersey (NJ), with 2011 peach production ranking 3^rd nationally (a $36.6 million value) and ranking 8^th for apple production which has a total Northeast production value of $437.4 million (USDA/NASS, NJ Ag Statistics 2012). Tree fruit are susceptible to dozens of insect pests, which were previously managed through IPM programs that focused on threshold-based applications of reduced-risk insecticides, mating disruption, and ground cover management. Under this program, parasitism of OFM eggs increased by 8.8-15.8% (Atanassov et al., 2003). However, in 2010 high populations of BMSB severely damaged up to 90% of the peach crop at some NJ and mid-Atlantic farms. There was an estimated $37 million loss in mid-Atlantic apples due to damage from BMSB alone (US Apple, 2011), with individual orchards averaging 60% fruit damage, and some reporting total crop loss (Leskey and Hamilton 2010). BMSB has thus established itself as the primary pest in these crops and population pressure currently remains high. The continued damage and threat of crop loss due to BMSB has devastated IPM programs in tree fruit, and forced growers back to weekly, calendar-based, broad-spectrum insecticide applications (Polk et al. 2010). Growers have expressed concern that “we are spraying too much - L. DeEugenio”.

 The disruption of fruit IPM programs through this radical shift in pest management has also upset the natural enemy complex within orchards leading to secondary pest outbreaks (Leskey et al. 2012). In the Northeast, orchards are experiencing high populations of wooly apple aphids and the return of white peach scale. Thus, the entire agricultural community is eager to develop sustainable and affordable management tactics for BMSB that reduces insecticide use and the adverse impacts on tree fruit agroecosystems. To combat this, a NE SARE funded project (ONE13-190) demonstrated a reduction in insecticide application and associated costs, but utilized an intensive monitoring program to determine BMSB abundance. This method resulted in the observation of only a few BMSB per farm, despite feeding injury demonstrating high BMSB pressure, which suggests an insufficient monitoring method. With eager support of our cooperating growers, we propose to expand this study to apples and integrate improved monitoring tools while investigating how a restructured IPM program can sustain natural enemy populations.

Proposed solution

Food production in the Northeast is of significant economic importance and agricultural sustainability (Martinez et al., 2010) through providing locally sourced foods and opportunities for farming families. Tree fruit growers have relied on IPM tactics to economically produce food for 40 years. However, since 2010 BMSB has disrupted IPM programs threatening the sustainability of locally produced fruit and forcing growers to return to broad-spectrum insecticide use with calendar-based scheduling to manage BMSB. While research has identified insecticides that are effective against BMSB, most have short residual activity requiring up to a 4-fold increase in insecticide applications (Leskey et al., 2012, 2013).

To combat the systems-level threat from BMSB, we propose to restructure management programs in peach and apple based on our previous results using behaviorally-based management, which we have termed “IPM-CPR” (Crop Perimeter Restructuring). Our previous SARE (ONE13-190) project demonstrated a 75% reduction in insecticide use in peach with border-only applications compared to current grower practices. Since most NJ peach growers also produce apples, it is essential to demonstrate this sustainable tactic in multiple fruit production systems, which will increase adoption in the Northeast. Expansion of IPM-CPR into apples will additionally mitigate issues with secondary pests arising from the overuse of pyrethroid insecticides.

Two years of on-farm trials demonstrate that IPM-CPR is a good agricultural practice that saved growers approximately $12/acre compared to alternate row middle applications. We observed no significant difference in BMSB abundance, catfacing damage, and no OFM injury in peach orchards under IPM-CPR (see attachment). Despite higher BMSB populations in 2013, our results suggest that IPM-CPR provides sustainable pest control at levels equal to current management recommendations. To evaluate systems-level impacts, we will measure natural enemy services and evaluate monitoring methods. Preliminary data on sentinel BMSB egg masses showed increased predation in the interior of IPM-CPR orchards. We want to explore this further as well as evaluate treatment impacts on populations of mites and scales, which can become problematic under intensive pyrethroid use. Advances in the chemical ecology of BMSB allow us to evaluate pheromone-based monitoring methods compared to unreliable visual counts.

This will be accomplished in commercial peach and apple orchards with growers who have expressed an immediate need for BMSB management strategies to reduce insecticide inputs.  The growers are: Carl Heilwig, Lewis DeEugenio Jr. and Anthony Yula, and Santo Maccherone. They are pleased with our results and eager to expand this into apples.

Our objectives include:

1) Investigate effectiveness of managing BMSB and key fruit pests with border sprays, mating disruption and ground cover management (IPM-CPR).

2) Investigate response of insect natural enemies and secondary pests under IPM-CPR.

3) Compare monitoring methods for BMSB in peach and apple orchards.

4) Partner with fruit growers to demonstrate IPM-CPR and record state-wide changes in insecticide use practices.

 By working directly with top fruit growers, we will demonstrate IPM-CPR in apples, and identify the impact on natural enemies through improved monitoring methods in peach and apple to facilitate adoption in the Northeast. The proposed research adheres to SARE goals by reducing pesticide inputs, exposure, and soil compaction.

Methods

Our project’s aim is to investigate the effectiveness of a systems-level approach to manage BMSB and key fruit pests with border sprays, mating disruption, and ground cover management (IPM-CPR) as a good agricultural practice, and the impact on natural enemies. Border sprays are an IPM tactic previously used in other systems (Vincent et al. 1997). They will be a critical component of this project to increase treatment efficiency and reduce insecticide use by applying treatments to only approximately 25% of a 5-acre peach block.

 Three sites each with two peach blocks and three sites each with two apple blocks will participate in the study for one year. At each site, an IPM-CPR treatment block and a grower standard block, each ca. 5 acres, each of the same variety (Jersey Queen – peach, Red Delicious – apple) will be sampled beginning mid-May, when BMSB colonizes peach orchards in NJ, through harvest. Preference for adjacent blocks of peach and apple will be used to look at movement between crops under IPM-CPR. The standard block will be maintained as full cover or alternate row middle insecticide applications for BMSB and other target pests on a 7-14 day schedule for BMSB and at DD timing for moth pests. IPM-CPR blocks will be maintained: under mating disruption (OFM TT in peaches and OFM/CM TT in apples, CBC America) at a rate of 100 ties/acre or 200 ties/acre, respectively. Participating growers will supply the required hand labor and record the time needed for mating disruption dispenser placement. Additional applications of reduced-risk insecticides for moth pests will be applied if needed. BMSB populations will be managed by treating only the perimeter row/trees and the first full row. Within the orchard, row middles will be managed with the application of an herbicide to control broad-leaf weeds, such as clover and other legumes, that may harbor populations of tarnished plant bugs (Lygus spp.) and native catfacing insects (Atanassov et al., 2002). In all blocks two monitoring traps will be placed on the interior of each orchard block to monitor moth populations. Early season pest management for plum curculio and green peach aphid will be applied as needed according to the 2014 Rutgers Tree Fruit Production Guide. Management for BMSB will begin at 148 DD₁₄^o_C when reproducing adults move into peach (Nielsen et al., 2008) and/or when traps indicate dispersal into apple.

In all blocks, populations and injury caused by OFM/CM, catfacing insects, and BMSB will be monitored weekly throughout the growing season in transects across the orchard (see attachment). Our previous trials relied on an intensive monitoring method that revealed few BMSB despite moderate injury. To make the IPM-CPR program friendlier to growers and scouts, we propose to compare two monitoring methods for BMSB. We will evaluate 3-minute visual counts relative to BMSB aggregation pheromone traps along the perimeter for their efficiency in detecting BMSB populations. It is hoped that by evaluating the aggregation trap we can move closer to developing trap-based thresholds in the future. If interior samples detect BMSB individuals and increases in catfacing injury growers will initiate a full block insecticide treatment, suggesting that populations have dispersed into the unsprayed interior of the block. Despite heavy rainfall in 2013, participating peach growers in the IPM-CPR trial only applied one full block insecticide application targeting BMSB. In all blocks, each replicate sample will include a 25 sweep sample in the orchard middle, OFM shoot strike counts, and an on tree count of 100 fruit for catfacing injury. At harvest, 50 fruit from each replicate sample per block (450 fruit/block) will be assessed for all insect damage, including BMSB. All fruit will be peeled to quantify the severity of BMSB injury per fruit. Participating growers will also be asked to grade a selection of fruit.

 Effective insecticides for BMSB management are predominately pyrethroid and neonicotinoid classes with a heavy reliance on the former. This approach increases applicator and worker exposure, may have downstream negative environmental impacts due to intense pyrethroid use, is harmful to the orchard agroecosystem, and is costly. The broad-spectrum action of pyrethroids has been detrimental to beneficial insects and outbreaks of secondary pests such as wooly apply aphid, mites, white peach scale, and San Jose scale has been widely reported. Thus, another objective of this project is to investigate the response of insect natural enemies and secondary pests under IPM-CPR program.The influence of management programs on natural enemies will be monitored 4 times during season with yellow sticky cards placed within the tree canopy along the transect samples (2 perimeter, 2 interior, and 1 middle). After one week the sticky cards will be collected and assessed for the prevalence of insect natural enemies. We will also demonstrate predation and parasitization of BMSB and OFM with sentinel egg masses. Sentinel eggs will be deployed at trees adjacent to sticky cards during the same time period but collected after 2-3 days. One BMSB egg mass (28 eggs/mass) and three OFM clusters (5 eggs/1x2.5cm strip) per tree will be used (Atanassov et al., 2003). After collection, all eggs/egg masses will be kept under laboratory conditions and predation or parasitism will be quantified. Secondary pests, including mites and scales, will be monitored based on pest phenology within peach and apple blocks. Predatory and pest mites will be sampled with a mite brush from 25 leaves/tree collected along the transects. Scales will be monitored through visual observations and using double-sided tape to monitor crawler stages.

The project will be incorporated into the existing Rutgers Cooperative Extension Fruit IPM Program, led by Mr. Polk, and will complement the research/extension efforts from Dr. Nielsen’s program. The target audience is the New Jersey commercial peach and apple industry, and ultimately the Northeastern tree fruit industry. Pest and natural enemy abundance data and clean fruit at harvest will be analyzed with ANOVA to demonstrate effectiveness of the IPM-CPR program. Pesticide records will be obtained from the grower collaborators, and analyzed with t-tests for the number of applications, amount of active ingredient used, and associated costs.

 Project Timeline

• April 2014 (Nielsen, Blaauw, and Polk): Establish and mark plots and provide management plans to growers. Hire hourly laborers.
• May – Sept, 2014 (Nielsen, Blaauw, and Polk): Weekly monitoring and data collection at farms. Interpret field data and consult with growers on management recommendations. Take video footage of sampling, identification and injury.
• June 2014 (Nielsen, Blaauw and Polk): Twilight meeting at cooperating grower sites to demonstrate IPM-CPR tactics. Take video footage of demonstration at grower orchard.
• June - August, 2014 (Blaauw): Place sticky cards and collect to monitor beneficial insects
• June - Sept, 2014 (Nielsen, Polk): Develop newsletter articles for commercial growers that include ongoing results and management in demonstration plots.
• Sept 2014: Recruit undergraduate student from Rutgers Mason Gross School of Art to create demonstration video.
• October, 2014 (Polk): Meet with growers and collect pesticide use records.
• October, 2014 (Nielsen and Blaauw): Analyze pest, beneficial insect, and pesticide use data. Develop extension fact sheet.
• December 2014 – March 2015 (Nielsen, Blaauw, and Polk): Present results at research and grower meetings. Share completed demonstration video of IPM-CPR program to Plant Pest Advisory, Nielsen lab webpage and grower meetings. Edit and expand the NJ Tree Fruit Production Guide to include results and project recommendations.

Outreach of results

We will utilize numerous outreach activities to ensure that the IPM-CPR program is demonstrated at the small scale and to a national audience that faces increasing pressure from the invasive BMSB in sustainable fruit production. The primary target audience is the NJ commercial tree fruit industry, as well as fruit growers in other Northeastern and mid-Atlantic states where BMSB is a severe problem. At the small scale, we will reach NJ growers through field days, extension meetings and publications. For national scope, we will disseminate project methods and results through research/extension meetings and demonstration video.

 Extension information that is gathered from the project will be incorporated into the delivery mechanism used in the Rutgers fruit IPM program. This program trains scouts and facilitates weekly IPM scouting in 40 orchards throughout NJ. Seasonal scouts collect weekly data, which is interpreted by researchers and used in newsletter recommendations. This established communication system permits us to seamlessly integrate our IPM-CPR tactics into current practices. Practical extension information pertaining to BMSB and other pest management recommendations will be made through 1) the online Rutgers Plant and Pest Advisory Newsletter, 2) one-on-one consultations and farm visits, 3) winter meetings (Mid-Atlantic Fruit and Vegetable Conference, Hershey, PA, South and North Jersey Fruit Meetings), 4) twilight grower meetings during the spring/summer of 2015, and 5) an updated section on BMSB management in the annual NJ Tree Fruit Production Guide. Due to the varied adoption of technology by growers, we will also work with our cooperating growers themselves to disseminate the information. Since the cooperating growers manage over 1,000 acres of New Jersey tree fruit production, we anticipate that other growers will learn from their leadership, and further adopt the practices demonstrated in this project.

 Through the Rutgers fruit IPM program, a field day will be held at one of the cooperating grower sites where the results and methods can be discussed along with hands-on demonstrations during summer 2014. During the field day and throughout the project, video of sampling, insect identification, injury, and methods will be taken. In collaboration with Rutgers Mason Gross School of Arts, a student intern will be trained to develop an educational video targeting extension educators on the project for course credit under the advisement of Dr. Nielsen. This video will be posted to the online Rutgers Plant Pest Advisory, which has 347 fruit subscribers (October 2013) and on Dr. Nielsen’s lab webpage.

Research findings will be presented regionally at the Cumberland Shenandoah Fruit Workers Conference in Virginia and nationally at the Entomological Society of America’s Annual Meeting in Oregon. Reports from researchers in California and Oregon have documented large populations and severe injury to apples, respectively. Although our proposed work will be conducted in Northeast fruit systems, it could be applied to orchard production systems elsewhere, thus potentially greatly increasing the impact.