Final Report for ONE14-217
The invasive brown marmorated stink bug (Halyomorpha halys [Stål] [Hemiptera: Pentatomidae]) (BMSB) has emerged as a key pest in mid-Atlantic peach and apple production. Current management of H. halys has disrupted IPM programs by relying exclusively on frequent, repeated, season-long insecticide applications. We developed a behaviorally-based tactic termed IPM-CPR (Crop Perimeter Restructuring) utilizing border sprays for BMSB, groundcover management for the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois) (Hemiptera: Miridae), and mating disruption for Oriental fruit moth (Grapholita molesta [Busck] [Lepidoptera: Tortricidae]) (OFM) and codling moth (Cydia pomonella [Lepidoptera: Tortricidae]) (CM). We adapted our previous methods from peach to expand this systems-level approach to manage BMSB and other key orchard pests into apples. We compared monitoring methods for BMSB and measured the treatment impacts on natural enemies and secondary pests.
We found that pheromone traps generally collected more BMSB and at a higher frequency than visual observational sampling throughout the season. As the pheromone in the pyramid traps attract BMSB to the traps, there is a chance that bugs feed on the fruit in the adjacent trees before being caught in the trap causing an increase in damage in those “trap trees”. In peaches, the trap trees had significantly more catfacing damage compared to the interior trees for both the standard and IPM-CPR treatment blocks, but trap-trees did not have more damage than the non-trap trees along the border (Fig. 4). In apples, trap trees had significantly more catfacing damage compared to both the non-trap trees and the interior trees for both the standard and IPM-CPR treatment blocks (Fig. 5). In both peaches and apples, damage from BMSB is higher along the orchard border, whereas the presence of the pheromone lure in the trap increases the damage in trees when used in apple orchards, but not in peaches. Generally, there was less, and at times significantly less, catfacing injury (attributable to BMSB) in peaches (Fig. 6) and apples (Fig. 7) in the IPM-CPR blocks relative to the standard, and minimal differences in injury due to tarnished plant bug, OFM, or CM.
The insecticides that are commonly used for BMSB management may also have negative effects on non-target insects within the orchard, such as insect natural enemies. IPM-CPR reduced the amount of insecticide active ingredient used by up to 55% in peaches and 5% in apples. In both peach and apple orchards we found significantly more natural enemies, such as lady beetles, lacewing, hoverflies, and spiders, in the IPM-CPR blocks (Peach: 14.4 natural enemies per sticky card; Apple: 47.2 natural enemies per sticky card) compared to the grower standard blocks (Peach: 10.2 natural enemies per sticky card; Apple: 12.5 natural enemies per sticky card). Additionally we also placed 2,520 BMSB sentinel eggs in orchards to measure natural enemy activity. In the peach orchards there was very little predation with no significant difference between eggs deployed in the standard blocks than in the IPM-CPR blocks. Conversely, there was significantly higher incidence of predation of BMSB egg masses that were placed in IPM-CPR blocks than in the standard blocks.
IPM-CPR significantly reduces the area managed by growers for control of BMSB, while simultaneously managing key pests at levels equal to current grower standard practices. This approach brings IPM tactics back into the orchard system after disruption by the invasion of BMSB and potentially supports beneficial insects.
- Figure 6. Average percent damaged from tarnished plant bug, catfacing, OFM, and scale insects on harvested, pealed peaches.
- Total season average of damaged peaches from on-tree, visual assessment of catfaced peaches due to BMSB on trap trees (adjacent to pyramid traps), non-trap trees, and interior trees.
- Total season average of damaged apples from on-tree, visual assessment of catfaced peaches due to BMSB on trap trees (adjacent to pyramid traps), non-trap trees, and interior trees.
- Figure 7. Average percent damaged from tarnished plant bug, catfacing, OFM/CM, and scale insects on harvested, pealed apples.
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 3rd nationally (a $36.6 million value) and ranking 8th 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).
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.
To evaluate systems-level impacts, we aimed to 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 wanted 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 allowed us to evaluate pheromone-based monitoring methods compared to unreliable visual counts.
This research was implemented at commercial peach and apple orchards with growers who have expressed an immediate need for BMSB management strategies to reduce insecticide inputs.
Our objectives included:
1) Compare monitoring methods for BMSB in peach and apple orchards.
2) Investigate effectiveness of managing BMSB and key fruit pests with border sprays, mating disruption and ground cover management (IPM-CPR).
3) Investigate response of insect natural enemies and secondary pests under IPM-CPR.
4) Partner with fruit growers to demonstrate IPM-CPR and record state-wide changes in insecticide use practices.
Field sites were set up at three peach orchards and three apple orchards,(The growers are: Carl Heilwig, Lewis DeEugenio Jr. and Anthony Yula, and Santo Maccherone. each with two blocks ca. 5 acres of the same variety (Jersey Queen – peach, Red Delicious – apple). At each site, one block was managed with the grower standard program and the other block was designated the IPM-CPR treatment block. The standard blocks were managed as full cover or alternate row middle (Fig. 1a&b) insecticide applications for BMSB and other target pests on a 7-14 day schedule for BMSB and at degree-day (DD) timing for moth pests. IPM-CPR blocks were managed:
- 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.
- Additionally, Apple orchards received mid-season applications of Madex (Certis USA, Columbia, MD) biopesticide for management of codling moth.
- BMSB weas managed by treating only the perimeter row/trees and the first full row of the orchard (Fig. 1c). Management for BMSB began at in late May in peaches and in mid- to late June in apples.
- Within the orchard, row middles were managed with the application of herbicide (clopyralid) to control broad-leaf weeds, such as clover and other legumes that may harbor populations of tarnished plant bugs and native catfacing insects (Atanassov et al., 2002).
For all peach and apple sites, two monitoring traps were placed on the interior of each orchard block to monitor OFM and CM (in apple only) populations.
To make the IPM-CPR program friendlier to growers and scouts, we compared two monitoring methods for BMSB. We evaluated 3-minute visual counts per site relative to four BMSB aggregation pheromone traps placed along the perimeter for their efficiency in detecting BMSB abundance (Fig. 1d). In all blocks, populations and injury caused by OFM/CM, catfacing insects, and BMSB were monitored weekly from May through harvest. Sampling occurred along four transects (two parallel with orchard rows and two perpendicular), each with two border and two interior (10 trees in) samples sites for a total of 16 sampling sites (Fig. 1d). Each sampling site consisted of two trees, adjacent to one another. One sampling site along each orchard border had a pheromone trap, which we compared to a sampling site that did not have trap in order to determine whether or not the pheromone traps amplified damage in adjacent trees.
In all blocks, at each sampling site along two transects, additional sampling included a 25 sweep sample in the orchard middle, OFM shoot strike counts during the 3-minute visual smpling, and an on tree count of 50 fruit (25/tree per sampling site) for catfacing injury. At harvest, 50 fruit from each of the 16 sampling sites were collected per block (800 fruit/block) and were assessed for all insect damage, including BMSB. Collected fruit was peeled to quantify the severity of BMSB injury per fruit.
The influence of management programs on natural enemies was investigated by utilizing yellow sticky cards placed in the orchards at 4 times during the season. Sticky cards were placed within the tree canopy at each of the sampling sites (2 perimeter and 2 interior) along one of the transects in each block. After one week the sticky cards were collected and assessed for the occurrence and abundance of insect natural enemies. At two peach and two apple orchards, we also deployed sentinel BMSB egg masses at three time periods in late July and early August to quantify predation and parasitization within the orchards. Sentinel eggs were attached to the underside of leaves at trees adjacent to sticky cards and were collected after 48 hrs. After collection, all eggs/egg masses were kept under laboratory conditions and predation or parasitism were quantified by assessing any damage of the eggs and allowing potential parasitoids to emerge. As a secondary pest, scales were monitored weekly through visual observations of double-sided tape attached to two terminal branches of four trees along one of the transects. Wooly apple aphids, another secondary pest, were monitored twice over two consecutive weeks in August. At each of the 16 sampling sites at each apple block, the number of unique wooly apple aphid (Erisoma lanigerum [Hausmann]) colonies were counted per tree over a 1 minute period.
Pest, natural enemy abundance, and fruit damage data were analyzed with Kruskal-Wallis analysis of variance (due to non-normality of data) to assess effectiveness of the IPM-CPR program.
Objective 1: Compare monitoring methods for BMSB in peach and apple orchards.
Typical observational monitoring for BMSB in tree fruit is time consuming and can potentially miss adult stink bugs that are high in the trees. Thus, in order to develop an easier more effective monitoring tool for growers and scouts, we deployed black pyramid traps baited with 10mg of BMSB aggregation pheromone plus MDT synergist. In peaches, visual sampling and traps caught the first stink bug of the season on the same date, although the average number of bugs observed in the trap was five times higher than visually observed in the trees. Throughout the season, more BMSB were found in the traps than were visually observed in the trees, but bugs were consistently, although in low numbers) observed by both sampling methods (Fig. 2). When utilizing the pyramid traps in apples, the first bug capture was on May 13 in the trap, but we did not see a BMSB in the apple trees until May 27 (Fig. 3). In apples, the traps caught stink bugs earlier and more consistently throughout the season than did visual sampling of the trees (Fig. 3). The traps are easier to check and take less time to monitor than visual observations of the trees, thus our findings suggest that pheromone baited pyramid traps may be more effective and efficient for monitoring BMSB abundances in both peach and apple orchards.
As the pheromone in the pyramid traps attract BMSB to the traps, there is a chance that bugs feed on the fruit in the adjacent trees before being caught in the trap causing an increase in damage in those “trap trees”. Thus, we compared on-tree damage (catfacing) through visual assessment of peaches and apples throughout the season on “trap trees”, non-trap trees, and trees on the interior of the orchard. For peaches there was no significant difference between treatments, standard and IPM-CPR, for any of the three sampling locations (Fig. 4). When comparing by sample location, there was no significant difference between trap trees and non-trap trees along the border no non-trap trees and interior trees, but the trap trees had significantly more catfacing damage compared to the interior trees for both the standard and IPM-CPR treatment blocks (Fig. 4). Similarly for apples, there was no significant difference between treatments for any of the three sampling locations, but trap trees had significantly more catfacing damage compared to both the non-trap trees and the interior trees for both the standard and IPM-CPR treatment blocks (Fig. 5). In both peaches and apples, damage from BMSB is generally higher along the orchard border, whereas the presence of the pheromone lure used in the trap appears to increase fruit damage in trees when used in apple orchards, but not in peaches.
Objective 2: Investigate effectiveness of managing BMSB and key fruit pests with border sprays, mating disruption and ground cover management (IPM-CPR).
To investigated how fruit damage was affected by standard versus IPM-CPR managed orchards, we harvested 800 fruit per block at each farm and for each crop, and assessed fruit for injury due to tarnished plant bug, catfacing due to BMSB, OFM stings (CM in apple), and scale. In peaches there was no injury due to OFM and no significant difference in the percentage of damaged fruit due to BMSB or scale, but the trend was that the damage was higher in the standard blocks. Additionally, injury due to tarnished plant bug was significantly higher (X2 = 7.7, P = 0.005) (Fig. 6). Similarly, in apple, there was no significant difference in fruit injury due to the measured insects, but numerically, injury was higher in apples from the standard blocks (Fig. 7). These data express that re-introducing common IPM tactics back into peach and apple management through the systems-level IPM-CPR tactic can manages key pests at levels equal to current grower standard practices.
Objective 3: Investigate response of insect natural enemies and secondary pests under IPM-CPR.
The disruption of fruit IPM programs through the substantial increase in insecticide usage to combat BMSB has also upset the natural enemy complex within orchards leading to secondary pest outbreaks. Thus we used a combination of yellow sticky cards, sentinel BMSB egg masses, and wooly apple aphid assessment to investigate how a reduction in insecticide usage through IPM-CPR can affect natural enemies and secondary pests.
In both peach and apple orchards we collected significantly more natural enemies on sticky cards in the IPM-CPR blocks (Fig. 8; peach: X2 = 4.01, P = 0.04; apple: X2 = 13.9, P = 0.001). The natural enemies that were caught on the sticky cards were primarily lady beetles, lacewing, hoverflies, and spiders. We also collected an abundance of parasitoid wasps, but only a single parasitoid adult emerged from the 2,520 BMSB eggs that were placed in the field. We did, however, measure predation on the egg masses. In the peach orchards there was very little predation with no significant difference between eggs deployed in the standard blocks than in the IPM-CPR blocks (Fig. 9). Conversely, although still relatively low, there was significantly higher incidence of predation of BMSB egg masses that were placed in IPM-CPR blocks than in the standard blocks (Fig. 10; X2 = 4.3, P = 0.04). Additionally, there were more wooly apple aphid colonies observed in standard apple blocks than in the IPM-CPR apple blocks (Fig. 11). While we only recovered a single parasitized BMSB egg, there was evidence of egg predation in IPM-CPR blocks within apple orchards. The potential added benefits of protecting natural enemies through IPM-CPR through the use of mating disruption and decreased insecticide inputs, there is likely a significant benefit to ecosystem services by the adoption of this technique.
Objective 4: Partner with fruit growers to demonstrate IPM-CPR and record state-wide changes in insecticide use practices.
Insecticide selection and application method (ARM or solid block) for grower standard was left to the individual grower’s discretion, so at the end of the season we obtained our grower cooperator’s spray records. By utilizing border only insecticide applications along with herbicide for tarnished plant bugs and mating disruption, IPM-CPR reduced the amount of insecticide active ingredient used in peaches by up to 55%. In the apple orchards growers also included an application of a biopesticide to the whole orchard, so that plus the other inputs, apple growers reduced insecticide input by 5% in the IPM-CPR orchards. While that reduction may not be significantly lower than the standard grower practice, the usage of biopesticides, such as Madex®, that target specific pests, and the reduced input of broad-spectrum insecticides can have substantial positive effects on beneficial insects. For example, as we saw in the IPM-CPR blocks in this study, there were significantly more natural enemies caught on sticky cards and higher percentage of egg predation in the IPM-CPR blocks.
- Figure 2. Comparison of the average number of BMSB caught in pyramid traps to visually observed on peach trees throughout the season (2014).
- Figure 3. Comparison of the average number of BMSB caught in pyramid traps to visually observed on apple trees throughout the season (2014).
- Figure 4. Total season average of damaged peaches from on-tree, visual assessment of catfaced peaches due to BMSB on trap trees (adjacent to pyramid traps), non-trap trees, and interior trees.
- Figure 7. Average percent damaged from tarnished plant bug, catfacing, OFM/CM, and scale insects on harvested, pealed apples.
- Figure 8. The average number of insect natural enemies collected on yellow sticky cards placed in standard and IPM-CPR treated blocks at peach and apple orchards.
- Figure 10. The percentage of eggs per egg mass that showed signs of predation after being placed in apple orchards for 48 hours.
- Figure 9. The percentage of eggs per egg mass that showed signs of predation after being placed in peach orchards for 48 hours.
- Figure 5. Total season average of damaged apples from on-tree, visual assessment of catfaced peaches due to BMSB on trap trees (adjacent to pyramid traps), non-trap trees, and interior trees.
- Figure 6. Average percent damaged from tarnished plant bug, catfacing, OFM, and scale insects on harvested, pealed peaches.
- Figure 11. The average number of unique wooly apple aphid colonies observed per minute on apple terminals.
We have demonstrated that a systems-level approach, termed IPM-CPR, can significantly reduce the area managed by growers for control of BMSB, while simultaneously managing key peach and apple pests at levels equal to current grower standard practices. This approach brings IPM tactics back into the orchard system after disruption by the invasive BMSB and potentially supports beneficial insects and the services they provide.
Education & Outreach Activities and Participation Summary
Information gathered in this project was disseminated through extension meetings and state recommendations. Extension information gathered from the project was incorporated into the delivery mechanism used in the Rutgers Cooperative Extension Fruit IPM Program. Recommendations resulting from this project were made through 1) the Plant and Pest Advisory Newsletter, faxed or emailed and available on the web, 2) through other broadcast email messages directly to growers, 3) an update to the 2015 NJ Tree Fruit Production Guide to include IPM-CPR tactics, 4) one-on-one consultations and farm visits, and 5) at a variety of professional and extension meetings (see list below). Additionally, a Nielsen lab page was created (http://nielsenentlab.weebly.com/), which highlights work currently being done by Anne L. Nielsen, including this SARE funded research on IPM-CPR. A handout summarizing some of the key findings from this project and our previous SARE project (ONE13-190) was created and distributed to growers at twilight and grower meetings (attached below). We are currently working on adapting the handout into a more detailed fact sheet on the identification and management of stink bugs that will be submitted through SARE. Along with the fact sheet, a short video describing the IPM-CPR technique is being created that will be published online to help distribute these methods to a broader audience.
Anne L. Nielsen, Brett R. Blaauw, and Dean Polk. 2014. Steps towards a systems-level approach to invasive species management for brown marmorated stink bug. Entomological Society of America Annual Meeting, Portland, OR.
Brett R. Blaauw, Dean Polk, and Anne L. Nielsen. 2014. Exploiting BMSB behavior as a management tactic in peaches. Specialty Crop Research Initiative BMSB Planning Meeting. February 11, 2014. Oral presentation
Anne L. Nielsen, Brett R. Blaauw, and Dean Polk. 2014. IPM CPR: The application of behaviorally- based strategies for successful management of BMSB in peach. Orchard Pest and Disease Management Conference. Portland, Oregon. January 8, 2014.
Anne L. Nielsen, Brett R. Blaauw, and Dean Polk. Mid-Atlantic Fruit and Vegetable Convention. “Bringing IPM Back to Peaches in the Face of BMSB.” Hershey, PA. Jan 29, 2015. (100 attendees)
Anne L. Nielsen, Brett R. Blaauw, and Dean Polk. Mid-Atlantic Fruit and Vegetable Convention. “Effective IPM Programs for BMSB in Peach: Better and Less Spraying.” Hershey, PA. Jan 29, 2014. (150 attendees)
Anne L. Nielsen. Great Lakes Fruit and Vegetable EXPO – “How to manage Brown Marmorated Stink Bug and not abandon IPM”, Grand Rapids, MI. (155 attendees)
Anne L. Nielsen. South Jersey Fruit Meeting, Bridgeton, NJ “Managing BMSB and OFM with Less Insecticides (and Less Money)”. (40 attendees)
Brett R. Blaauw and Anne L. Nielsen. South Jersey Fruit Twilight , Glassboro, NJ. “Insect Management Update”. (25 attendees)
Anne L. Nielsen. North Jersey Fruit Meeting, Pittstown, NJ “Management of BMSB and New Insecticides for Key Fruit Pests”. (55 attendees)
While adoption of border focused insecticide applications to manage BMSB as part of the IPM-CPR tactic is not widespread, this tactic was well received by our grower cooperators ( Carl Heilwig, Lewis DeEugenio Jr. and Anthony Yula, and Santo Maccherone). They were disappointed that we were not continuing to do this research on their farms the following years, but are considering implementing the IPM-CPR tactic on their own through advisement from Anne L. Nielsen and Dean Polk. This will hopefully lead to other growers in the state adopting IPM-CPR for peach and apple management.
Areas needing additional study
This project demonstrated that the implementation of IPM-CPR can reduce the amount of insecticide used, while simultaneously managing key peach and apple pests at levels equal to current grower standard practices. IPM-CPR method still, however, requires growers to apply insecticide to the orchard border on a 7-10 day cycle. Ideally, insecticide applications for BMSB would be driven by thresholds, but spray thresholds do not exist for BMSB in tree fruit. Thus, a very important additional area of study is spray thresholds for BMSB management. Success of IPM-CPR has been documented in peaches and apples in New Jersey, but more work is needed to understand how this approach would work in other cropping systems, regions of the country, and in areas of higher populations of stink bugs. Furthermore, as pollinator health becomes increasingly important and this technique reduces the overall application of insecticides to an orchard, it essential that we better understand how IPM-CPR can affect orchard pollinators.
Atanassov, A., P. W. Shearer, G. Hamilton, and D. Polk. 2002. Development and implementation of a reduced risk peach arthropod management program in New Jersey orchards. Journal of Economic Entomology. 95: 803-812.
Atanassov, A., P. W. Shearer, and G. C. Hamilton. 2003. Peach pest management programs impact beneficial fauna abundance and Grapholita molesta (Lepidoptera: Tortricidae) egg parasitism and predation. Environmental Entomology. 32: 780-788.
Hoebeke, E. R., and M. E. Carter. 2003. Halyomorpha halys (Stål) (Heteroptera: Pentatomidae): a polyphagous plant pest from Asia newly detected in North America. Proceedings of the Entomological Society of Washington. 105: 225–237.
Leskey, T. and G. Hamilton. 2012. 2012 Brown marmorated stink bug IPM working group meeting report (November). Northeastern IPM Center. http://www.northeastipm.org/neipm/assets/File/BMSB-Working-Group-Meeting-Report-Nov-2012.pdf.
Leskey, T. C., B. D. Short, B. R. Butler, and S. E. Wright. 2012. Impact of the invasive brown marmorated stink bug, Halyomorpha halys (Stål) in mid-Atlantic tree fruit orchards in the United States: case studies of commercial management. Psyche: Journal of Entomology. doi:10.1155/2012/535062.
Martinez, S., M. Hand, M. Da Pra, S. Pollack, K. Ralston, T. Smith, S. Vogel, S. Clark, L. Lohr, S. Low, and C. Newman. 2010. Local Food Systems: Concepts, Impacts, and Issues. USDA – Economic Research Service. Economic Research Report Number 97. pp. 1-80.
McPherson, J. E. and R. M. McPherson. 2000. Stink Bugs of Economic Importance in America North of Mexico. CRC Press LLC, Boca Raton, FL. 253 pp.
Nielsen, A. L., and G. C. Hamilton. 2009. Seasonal occurrence and impact of Halyomorpha halys (Hemiptera: Pentatomidae) in tree fruit. Journal of Economic Entomology. 102: 1133-1140.
Polk, D.F., Schmitt, D., and Atanassov, A. 2010. Fruit quality and spray programs in NJ orchards. Proceedings, 85th Annual Cumberland-Shenandoah Fruit Workers Conference. Winchester, VA.
USDA/NASS, NJ Ag Statistics. 2012. Fruit and Vegetable Crops Statistics & National Rankings – New Jersey. United States Department of Agriculture - National Agricultural Statistics Service. http://www.nass.usda.gov/Statistics_by_State/New_Jersey/Publications/Fruit_Vegetables_Rankings/RANKINGS_final.pdf
Vincent, C., G. Chouinard, N. J. Bostanian & Y. Morin 1997. Peripheral-zone treatments for plum curculio management: validation in commercial orchards. Entomologia Experimentalis et Applicata. 83:1-8.