Final report for LNE14-334
The project aims to develop pheromone-based tools for management of the invasive brown marmorated stink bug (BMSB) and promote adoption by commercial apple growers in the mid-Atlantic region. Ten apple growers from 5 states that participated in this project and used baited pheromone traps to monitor BMSB populations and make management decisions and they implemented attract and kill technology (AK) in select border row trees to take the place of full block insecticide treatments. Results achieved in these blocks were compared with grower standard blocks on each farm. Prior research has demonstrated that the BMSB aggregation pheromone in combination with a monitoring trap can be used to manage the pest based using a trap-based treatment threshold. In 2015, monitoring traps in AK and grower standard blocks triggered 0.7 and 1.6 additional sprays per orchard block, respectively. In 2016, adult populations were nearly 3-fold greater and threshold sprays were triggered 1.8 times in AK blocks and 1.9 times in grower standard blocks. AK was successful at managing BMSB in commercial apple orchards with equivalent control or, in many cases, superior control to standard grower practices.
These results were highlighted at a field day in Maryland attended by 150 growers from throughout the mid-Atlantic. In addition, other presentations in PA, WV, MD, NJ and MI made to grower groups reached an additional 1000+ growers directly. We also maintained a project blog (http://williammorrison.wix.com/sare-blog) (20+ total posts), created a video about attract-and-kill principles on YouTube (over 500 views). We surveyed growers at the start, midway and at the conclusion of the project. At the conclusion of the project, of the 233 growers surveyed, 79.8% indicated that they would be interested in using pheromone-based tools, particularly monitoring traps on their farms. This equates to over 14,000 acres. The final step to reaching this level of adoption will be standardization of pheromone lures by commercial companies and trap designs by researchers coupled with additional educational and outreach efforts. Toward that end, we have continued to work with commercial companies; pheromone lures designed for both monitoring and for attract and kill are now available for purchase. Additionally, long-lasting insecticide treated nets (LLINs) are now being evaluated as a potential replacement for broadcast insecticides in attract and kill systems; this new technology likely will increase adoption of this tactic as this method eliminates the need for weekly insecticide applications at attract and kill sites by growers.
Performance target: Fifty apple growers in the mid-Atlantic will adopt pheromone-based tools for managing BMSB on 650 acres. Their adoption will reduce total full-block insecticide applications by 40%, decreasing costs from $154 to $92 per acre for season-long BMSB management, with additional savings in fuel and labor.
The unexpected introduction and subsequent establishment of a destructive invasive species often forces researchers, stakeholders, and growers to rapidly develop alternative management tactics. One species where this has held true is the invasive brown marmorated stink bug (BMSB), Halyomorpha halys (Hemiptera: Pentatomidae). Originally from Beijing, China, BMSB was accidentally introduced in the late 1990s in the USA,and since that point has spread to 43 USA states. The species feeds on over 170 host plants, many of economic importance as food crops (www.stopbmsb.org). In 2010, infestation of fruit and vegetable crops by BMSB reached outbreak status, and was estimated to have caused $37 million USD in damage to apple in the Eastern USA. In response, growers applied as much as four times more insecticide in order to ameliorate the damage caused by BMSB. Since that point, BMSB has become a global invasive species, causing problems in Canada and Europe, with a projected range expansion incorporating many more locations. Since 2010, pheromone-based technology for BMSB has been rapidly developed in the USA. Prior to 2012, methyl (E,E,Z)-2,4,6-decatrienoate (MDT, hereafter) was used to monitor BMSB populations in combination with large wooden pyramid traps. More recently, the male-produced BMSB aggregation pheromone (aggregation pheromone, hereafter) was identified as a mixture of two stereoisomers of 10,11-epoxy-1-bisabolen-3-ol. When the aggregation pheromone and MDT were combined in traps, a synergistic effect on field attraction of BMSB adults and nymphs was observed. BMSB is a perimeter-driven pest, often invading fields from the edge, and is usually most abundant along the edges of crops. In apple, the highest occurrence of injury is along the edges of orchards in the Mid-Atlantic region of the USA. As a result, pheromone-baited traps used for monitoring for BMSB often happens along the edges of fields and orchards to intercept the pest. One such system utilizes captures in pheromone-baited pyramid traps on the exterior and interior of apple orchards to trigger two back-to-back alternate row middle sprays over two weeks based on a cumulative provisional threshold. This has been shown to reduce insecticide usage by 40% while maintaining crop quality. The second strategy is termed attract-and-kill, whereby adults and nymphs are attracted to a spatially circumscribed area and removed from the population through the regular application of pesticides.. The goal of the current study was to implement trap-based monitoring and attract-and-kill to manage BMSB in commercial apple orchards in five USA Mid-Atlantic States to reduce insecticide inputs and secondary pest problems.
Brown marmorated stink bug (BMSB) is an invasive stink bug native to Asia that is a key pest of apple. This perimeter-driven pest has been managed successfully in apple orchards using pheromone-baited pyramid traps to trigger two back-to-back alternate row middle (ARM) sprays when a cumulative provisional threshold is reached. This approach has been shown to reduce insecticide usage by 40% and deliver excellent pest control. In addition, preliminary studies aimed at developing an ‘attract and kill’ strategy for BMSB in apple orchards using baited apple trees treated weekly with insecticide could successfully manage BMSB, while reducing insecticide inputs further. Our hypothesis was that pheromone-baited traps in and attract and kill technology deployed in apple trees could manage BMSB effectively in commercial apple orchards while reducing insecticide inputs.
This study was performed on 10 commercial apple farms in five Mid-Atlantic States in USA, including Maryland, New Jersey, Pennsylvania, Virginia, and West Virginia from 1 Jun to 14 Oct 2015 and 6 Jun to 30 Sep 2016. On each of the 10 farms, one apple orchard was randomly assigned as the grower standard (control) block, while another as the attract-and-kill (treatment) block. In the standard block, management BMSB was solely determined by each grower using standard practices. Management of other orchard insects and diseases followed standard extension recommendations and were identical between the standard and attract-and-kill blocks within a farm. In each attract-and-kill (AK) block, AK trees were spaced every 50 m around the perimeter of the orchard and baited with high dose pheromone and pheromone synergist lures. Lures were replaced every four weeks during the sampling period. The pheromone-baited tree and the trees within 5 m to either side were treated along the outward facing edge of the block by the grower with an insecticide on a weekly basis with a legal recommended spray program Plots were treated from the beginning of experimentation in June to the last harvest of fruit in Sep or Oct (depending on the field and year).
Three black pyramid traps were deployed with monitoring lures and kill strips to retain captured bugs. Traps were positioned in a diagonal transect through the center of the block and between apple trees in the rows. Traps were spaced approximately 50 m apart and checked on a weekly basis for the presence of adults and nymphs. Traps were used to trigger sprays if BMSB populations reached a damaging level in plot interiors, based on a cumulative threshold of 10 adults per trap. Once threshold was reached, two weekly ARM sprays were recommended to the grower over a 2-week interval, and the threshold was then reset and border sprays resumed
Fruit was sampled at harvest when a majority of the cultivars were ripe and/or if more than one block edge was to be fully harvested. In each destructive sample, fruit were collected from interior and perimeter trees.. Ten fruit per tree were harvested from the mid- to upper-canopy, where damage is often most severe. The proportion of injured fruit (frequency of damage) and the number of internal corking sites per fruit (severity of damage) was recorded.
To measure mortality of BMSB at baited AK trees, tarps were placed beneath 5-7 baited trees and compared with unbaited trees in the standard block on 3-4 farms across the same number of States in the USA. The tarps were checked on a weekly basis for the presence of adults and nymphs, and after each check, all individuals were removed from the tarp and disposed of to prevent recolonization..
Natural enemies were sampled using yellow sticky cards (at three time periods during the season. The number of predators and parasitic wasps were recorded from each card. Mite sampling occurred in conjunction with the deployment of sticky traps. Five leaves were randomly collected from ten trees per block at each farm, which were then brushed onto detergent-coated glass plates, using standard mite brushing machines in the laboratory. Herbivorous and predatory mites were counted using a dissecting microscope.
A subset of three farms were chosen for analysis of the costs associated with AK and grower standard programs for insect management. The growers selected were located in: MD, VA, and WV. The categories chosen for analysis were: insecticide cost per ha, cost of lures for baited trees, cost of labor to deploy and replace lures on baited trees, and crop loss adjusted for bushels harvested per ha. At the time of this study, the experimental lures were priced at nearly $10 per lure. In this economic analysis, processed apple downgrade was calculated at an 80% loss in value. Expense categories of information not included: fuel and labor for insecticide application and loss of fruit on pheromone-baited trees. Monitoring trap expenses were not included as they were used identically in both AK and grower standard blocks. The cost of a bushel of apples was priced at $20 for all farms as a fresh market standard in the Mid-Atlantic area in USA. Whole plot applications of insecticides were standardized at 378.5 L of water per 0.405 ha. For the AK tree insecticide applications, the estimated gallon usage was conservatively calculated at 37.9 L for all farms as tree size and number of baited trees varied.
Fruit growers in the Mid-Atlantic region of USA were surveyed about whether they experienced damage from BMSB and their perceptions of monitoring traps and attract-and-kill technology. Surveys were administered at national and regional extension meetings, winter fruit schools, IPM training courses, and other grower outreach events in the off-season from Jan-Apr in 2015 - 2017 in MD, NJ, PA, VA, and WV.
Prior research has demonstrated that the BMSB aggregation pheromone in combination with a monitoring trap can be used to manage the pest based on a moderate cumulative threshold Populations were lower in 2015 compared with 2016. In 2015, monitoring traps in AK and grower standard blocks triggered 0.7 and 1.6 additional sprays per orchard block, respectively. In 2016, adult populations were nearly 3-fold greater based on trap captures and threshold sprays were triggered 1.8 times in AK blocks and 1.9 times in grower standard blocks. Triggered sprays in AK and grower standard blocks occurred mainly in the late season when populations were the largest during both years.
We have demonstratedthat attract-and-kill can be used to manage BMSB in commercial apple orchards with equivalent control or, in many cases, superior control to standard grower practices. By harvest in both years, the proportion of injured fruit was equivalent or reduced by half on interior trees in the attract-and-kill blocks compared twith grower standard. In 2015, interior damage in AK and grower standard blocks was 8.6% and 15.8% respectively. In 2016 when BMSB populations were higher, AK blocks averaged 16.0% while grower standard blocks averaged 27.3%.
These results can be explained by the degree of aggregation of BMSB adults and nymphs on AK trees. Presumably attract-and-kill sites were able to intercept incoming H. halys adults and nymphs as they reached apple blocks, and retain them long enough for exposure to a lethal dose of insecticide, allaying concerns of escaping adults with only sublethal exposure to killing agents. At a select number of AK-baited trees over two years, we were able to demonstrate mortality of over 10,000 individuals. The number of BMSB adults recovered beneath these tarped AK and grower standard trees were significantly different; in 2015 and 2016, 99.6% and 99.9% of the dead BMSB adults, respectively, were on baited AK trees. Unsurprisingly, treatment had a significant influence on the mortality of adults in both 2015 (F1,45 = 33.9; P < 0.0001) and 2016 (F1,40 = 16.2; P < 0.0001;), with 113 and 1,630 times more adults killed on AK trees than grower standard trees, respectively. In addition, the sampling period also significantly influenced the mortality of adults in 2015 (F2,523 = 32.2; P < 0.0001) and 2016 (F2,576 = 147.0; P < 0.0001). Over 5 and 15 times more adults were killed in the 2015 harvest period compared with the early and mid-period, respectively, while 7 and 14 times more adults were killed in the 2016 harvest period compared with the two same periods. In 2015 and 2016, 98.3% and 99.7% of the dead H. halys nymphs were found on baited attract-and-kill trees, respectively. Treatment significantly influenced the mortality of nymphs in 2015 (F1,45 = 1497; P < 0.0001) and 2016 (F1,40 = 158.8; P < 0.0001), with 60 and 290 times more nymphs killed on attract-and-kill trees than grower standard trees in 2015 and 2016, respectively. The sampling period also significantly affected mortality of nymphs on trees in 2015 (F2,523 = 1524; P < 0.0001) and 2016 (F1,576 = 153.1; P < 0.0001), with 15 and 10 times more nymphs killed in the harvest period compared with the mid-period, respectively.
Unexpectedly, the use of AK did not increase natural enemy nor decrease secondary pest abundance over the two year study. AK may need to be implemented for a longer period of time before observing improvements to the natural enemy community. Because natural enemies are highly mobile insects, it may be possible that there would need to be a greater number of attract-and-kill blocks on a farm to reap the benefits of decreased insecticide usage and increased refuges for beneficial arthropods. In 2015, there were an average of 9.7 ± 1.6 (mean ± SE) and 11.3 ± 1.3 predators and parasitic wasps, respectively, captured on yellow sticky cards in attract-and-kill blocks, while there were 9.5 ± 1.1 and 11.2 ± 1.7 in grower standard blocks, respectively. The treatment did not significantly affect the abundance of predators on sticky cards (ANOVA: F1,230 = 0.239; P = 0.626) nor the abundance of parasitic Hymenoptera (F1,230 = 0.756; P = 0.387). In 2016, there were an average of 8.1 ± 1.2 (mean ± SE) and 13.3 ± 1.3 predators and parasitic wasps, respectively, on yellow sticky cards in AK blocks compared to 8.3 ± 1.8 and 14.9 ± 2.0 in the grower standard blocks. Similar to 2015, the treatment did not significantly influence the abundance of predators (ANOVA: F1,186 = 2.08; P = 0.157), or parasitic wasps (F1,186 = 2.79; P = 0.098) captured on sticky cards. AK had no effect on the abundance of herbivorous mites recorded (ANOVA: F1,154 = 0.007; P = 0.933) in 2015 or ANOVA: F1,156 = 0.489; P = 0.486) compared with grower standard blocks, nor did it affect predaceous mites in 2015 (ANOVA: F1,154 = 0.683; P = 0.410) or 2016 (ANOVA: F1,156 = 0.319; P = 0.574).
During 2015 and 2016, using the attract-and-kill strategy decreased monetary crop losses by almost 30% in 2015 and 16% in 2016 compared with grower standard practices, translating to $1,545-$1,933 and $779-971, respectively in additional value of the crop based on processing and whole crop loss, respectively. However, when factoring in the additional costs of experimental attract-and-kill the treatment costs were still over 10 times more expensive than the cost of grower standard tactics. It is important to consider other aspects as well, including economic feasibility, which is a significant caveat to this approach. If one strictly looks at lowering the lure cost to equal out the monetary difference between the grower standard and attract-and-kill blocks, the price of the lures would need to drop by ~50% (based on whole block losses) or ~66% (processing block losses) per ha to equal standard apple production costs. However, the costs represented in this report were for experimental and special order lures that were not commercially available to growers at the time. Since this study started, new synthetic pathways for producing these pheromones have become available, and a wider range of companies have started producing lures at lower costs. It should be noted that another option for growers to increase fruit quality using pheromone-based technology would be to apply additional, well-timed insecticide sprays based on pheromone-baited monitoring traps. The price of monitoring lures and traps is very economical options for growers adding ~ less than $20 ha.
Survey responses were received from 586 growers over three years. Over the course of the three years, the percent of growers reporting damage from H. halys ranged from 69-75% of total respondents experiencing stink bug damage annually. Over the course of the project, the percent of growers interested in AK declined from 80% to 50%, likely due to the cost of lures. However, the percentage of growers interesting in implementing pheromone-based tools, particularly monitoring traps for BMSB on their farm increased annually from 65.7% in in 2015, to 73.1% in 2016, to 79.8% of growers in 2017.
To summarize, we have documented the novel use of pheromone technology in commercial apple orchards in the Mid-Atlantic region of the USA, one of the regions impacted most severely by the invasive BMSB. We have demonstrated that we are able to reduce both the proportion and severity of injured fruit under differing population intensity, while reducing the amount of area sprayed for BMSB by 97% in AK sites. However, deployment considerations and production costs still need to be optimized to improve the economic feasibility of AK compared with conventional management. However, pheromone-baited monitoring traps provide a sensitive decision support tool to manage BMSB in apple orchards that is effective both ecologically and economically and likely to be adopted by affected growers. In terms of our performance target “Fifty apple growers in the mid-Atlantic will adopt pheromone-based tools for managing BMSB on 650 acres (263 ha)”, we appear to be able to meet this target as 183 growers are interested in implementing pheromone-based tools on over 14,000 acres (5668 ha) based on surveys conducted in early 2017 at the Mid-Atlantic Fruit and Vegetable Conference, at the Michigan IPM Fruit School and at regional winter meetings in Maryland and New Jersey. The permanent adoption of these tools continues in concert with their standardization and refinement under ongoing projects including the USDA-ARS Areawide Project and USDA-NIFA BMSB SCRI CAP to enable widespread adoption.
In July 2016, the research team organized a field day in Maryland specifically to highlight the work being performed with pheromone-based tools for the monitoring and management of BMSB on two collaborating growers orchards in Thurmont, MD and Woodbine, MD. We had attendance of over 150 growers from the mid-Atlantic region who learned more about attract-and-kill technology, the use of trap-based thresholds for management of BMSB, and we discussed the behavioral basis for why pheromone-based technology works for this invasive species. Collaborating growers were on hand to provide their perspective on the project. We also highlighted some of the challenges of the project (namely cost of pheromone for attract-and-kill and in-orchard time), and future directions.
1. Two hundred mid-Atlantic tree fruit growers will receive a questionnaire to establish baseline information regarding current BMSB management practices, their concerns over economic injury and secondary pest problems and their willingness to adopt alternative strategies such as attract-and-kill systems. (January-March 2015)
A survey was distributed at Winter Fruit Schools, regional extension meetings, IPM training courses, and other grower outreach events from January-April 2015 prior to the start of the project. Two hundred and twenty eight growers participated in the survey. Among them, 76.2% reported damage from BMSB in their orchards. The minimum affected acreage was estimated to encompass over 13,000 acres in WV, VA, MD, PA and NJ. Over 80% indicated they were interested in learning more about attract and kill technology.
2. Two hundred growers will learn about proposed attract-and-kill systems for BMSB management in apple through grower meetings, Extension presentations and online resources. (February-March 2015)
At Extension meetings, growers learned more about how to identify BMSB adults and nymphs. The updated Field Guide to Stink Bugs https://pubs.ext.vt.edu/444/444-356/444-356.html wad distributed at many of these meetings. This guide was the direct results of a complementary survey conducted as part of the StopBMSB project that found confusion among species for many growers. Additionally, growers were provided with updates on use of insecticides that were effective against BMSB as well as timings for their application. They were provided with an overview of the concept behind attract and kill technology and the potential for implementation in apple orchards. Ten growers agreed to join the project.
3. One hundred growers will return the survey and participate in education programs designed to enhance knowledge of BMSB identification, ecology, and management. Ten growers will agree to collaborate in research trials, documenting the utility of attract-and-kill systems. (April 2015)
Two hundred and twenty eight surveys were returned. Ten growers agreed to collaborate on the project and establish attract and kill blocks in apple orchards on their farms.
4. Ten growers will establish plots with attract-and-kill systems in combination with monitoring traps at their farms and each grower will receive project team support regarding deployment of attract-and-kill trees and traps, insecticide selection and season-long management programs for BMSB and other major pests. (April-September 2015)
Two growers from MD, WV, PA, NJ and VA participated in the project. Each grower established an attract and kill block based on the team-derived protocol and a second standard block for comparison. The size of orchard blocks varied from 1-5 acres each, depending on the type of farm (pick-your-own, fresh market, processing, etc.). Project team researchers deployed pheromone lures in select apple trees spaced ~50 m apart around the orchard edge and also deployed monitoring traps to ensure BMSB populations were not reaching relative densities that would lead to serious economic injury in attract and kill plots. The same traps were deployed in the standard comparison block. Each week, project team members (researchers and growers) would meet to review how things were going, including captures in monitoring traps, to determine if additional intervention, i.e., insecticide sprays, were necessary in BMSB blocks. At harvest, fruit was harvested from attract and kill and standard blocks to assess for BMSB injury. At harvest, there was 3-5 times more damage on fruit in the grower standard than in the attract-and-kill blocks with an average of 16% and 8% fruit injury, respectively. However, BMSB pressure was very low during the 2015 season and this was accurately reflected in captures in pheromone-baited traps. Thus, in blocks managed using standard practices, but with BMSB management decisions guided by trap captures, an average of 1.5 sprays were triggered based on our provisional trap-based treatment threshold. Compared with previous years in the region, this was a reduction of 87% in thenumber of sprays triggered –again demonstrating the low BMSB pressure in 2015. In attract and kill blocks, an average of 0.5 sprays were triggered by trap captures.
5. One hundred growers will attend field days at research and commercial farms to learn about benefits and challenges of attract-and-kill systems for BMSB management. (July-September 2015)
Approximately 240 growers learned more about the basics of BMSB attract and kill systems and pheromone-based monitoring, but none of these meetings were designed specifically to explain and discuss the ongoing project as it had just been implemented. It was decided by the team to plan for a summer meeting after data were generated to enable a more robust discussion with the grower community was warranted.
6. Ten growers will complete customized recording templates and evaluate the benefits and constraints of these practices with the project team in-person, by phone, or email. (December 2015-January 2016)
From these customized templates and/or face-to-face discussions with collaborating growers, several issues emerged. First, it was difficult for growers to literally keep up with spraying attract and kill trees on a weekly basis. As growers head into July-August, their attentions are often diverted to other critical tasks such as harvest of early cultivars of fruit. This led to frustration on the part of some of our growers. Moreover, growers also pointed out that filling up a spray tank and driving an airblast sprayer around their farm was a burdensome amount of labor. It was clear that as this project moved forward ang growers be willing to adopt this strategy, a mechanism for reducing this labor sink was going to be necessary.
7. After Year 1 results are disseminated, 100 growers will complete a mid-term questionnaire administered through grower meetings and the project team will evaluate progress, develop necessary modifications for Year 2, and implement them. (February-April 2016)
In the winter and early spring of 2016, we were able to gather mid-project survey from almost 140 growers in the mid-Atlantic. This survey was distributed to growers at 10+ regional and state Extension meetings, and reached an estimated audience of 400+ growers. Using this survey, we were able to assess the nature of the problem with BMSB and adoption of tools to mitigate its effects during the middle of the project.
The number of growers experiencing BMSB damage on their farms was slightly down to 71% (decrease of 15% from the previous year), which conforms with other data indicating that 2015 was a very low population year. Importantly, in 2016 there was a 10% increase in interest for adoption of pheromone-based monitoring tools for BMSB, with planned adoption in the following year or current use on 2,250 additional acres of apple over 2015, a number well above our performance target. In total, 56% of growers reported being interested in attract-and-kill, and 67% of growers reported being convinced that attract-and-kill could adequately manage BMSB.
8. In Year 2, ten growers will re-establish plots with attract-and-kill systems in combination with traps in apple, and each grower will receive support from project team members during the growing season for management issues. (April-September 2016)
In 2016, two growers from MD, WV, PA, NJ and VA again participated in attract and kill trials. That year, we had 2.5 times greater populations of adults, and >27 times greater nymphal BMSB populations, providing a good comparison to the very low population prior year. At harvest, there was statistically equivalent frequency of damage on perimeter trees between the attract-and-kill block (32%) and the grower standard (38%). In the interior trees, there was about half the amount of damage in the attract-and-block (15%) compared with the grower standard (27%). There was about half the severity of damage in perimeter and interior attract-and-kill trees compared with fruit in the grower standard block.
The use of attract-and-kill appears highly efficacious in managing the threat posed by BMSB. At the same time, use of attract-and-kill reduced the number of trees treated in the orchard by 97% and the amount of insecticide active ingredient used by 80% compared to typical full block or alternate row middle treatments for BMSB. This reduces the cost of insecticides from ~$30-100 per acre in the grower standard to ~$6-20 per acre in the attract-and-kill treatment. However, labor associated with this strategy was burdensome for participating growers.
In July 2016, the research team organized a field day in Maryland specifically to highlight the work being performed with pheromone-based tools for the monitoring and management of BMSB on collaborating grower orchards. We had attendance of over 150 growers from around the region participate, and we showcased attract-and-kill technology, demonstrated the use of threshold-based monitoring, and discussed the behavioral basis for why pheromone-based technology works so well. We also highlighted some of the challenges of the project, and future directions. In addition, another field day on the West Virginia University Organic Farm was organized by WVU, with attendance of 40 growers and members of the public. Pheromone-based monitoring and management tools were also discussed there.
9. At the end of the project, 100 growers will complete an overall project performance evaluation questionnaire, and the project team will analyze and deliver project outcomes including benefits and challenges of attract-and-kill systems via workshops, grower meetings, and online networks. (July-September 2016).
Growers at the Mid-Atlantic Fruit and Vegetable Meeting in Hershey, PA, at the Michigan State Tree Fruit IPM School in Traverse City, MI, and at regional meetings in MD and NJ learned more about the attract and kill project including final results and participated in the survey. All regions surveyed have a history of severe BMSB injury in tree fruit orchards (the mid-Atlantic region) or are starting to experience injury (Michigan). In total, 233 growers completed the survey. Among them, 79.8% or 186 individuals indicated they would be interested in using pheromone-based tools on their farms, particularly monitoring traps. The acreage of these tree fruit growers interested in adoption pheromone-based technology comprises 14,730 acres (~5963 ha) with an average acreage per grower ~80 acres.
Milestone Activities and Participation Summary
Key areas in which knowledge, attitudes, skills and awareness by farmers were increased include:
- Effective insecticides against BMSB and the consequences of broad-spectrum materials, i.e. secondary pest outbreaks
- The use of monitoring traps to determine the need for and timing of insecticide applications against BMSB.
- The utility of attract and kill systems used against BMSB, but also the need to make the system more affordable and less labor intensive
- The potential for long-term solutions such as biological control, including classical biological control programs, for invasive pests.
- The disruptive nature of invasive species in agroecosystems.
We used surveys at regional meetings, field days, and face-to-face discussions with our participating and other interested growers. There is no question that BMSB made its mark on the grower community; the impact of this pest on IPM programs still continues, albeit not as acutely as a few years ago. Since the original project wrapped, we have continued to collaborate with our participating growers from original project (10) on related BMSB projects, and we have added additional cooperators that agreed to continue to improve attract and kill technology and monitoring traps as well as redistributing the Asian parasitoid of BMSB on their farms (7).
Performance Target Outcomes
They will adopt pheromone-based tools to manage BMSB
The amount of production affected will be ~650 acres
The use of pheromone-based tools will reduce the total full-block applications against BMSB by 40%.
These growers are using pheromone-based tools to monitor BMSB.
Approximately 200 acres was affected by this change.
Growers have actively monitored their farms to establish if BMSB is a threat and determine if insecticide applications were necessary.
One of the challenges in verifying growers adopting pheromone-based tools for BMSB is that lures and tools are still being standardized and optimized to maximize adoption. There is no question that there is great interest in their adoption based on our extensive surveys, but commercial providers have spent the past few years tweaking their pheromone formulations to enable them to be more affordable and long-lasting.
To date, Trece has worked with us and other researchers on this project to optimize a pheromone lure for BMSB that is available. We now have a monitoring lure that costs $4.35 and last for 12 weeks. We also have been working on a simpler trap design to replace the pyramid trap (~$35 each). Clear sticky cards deployed on wooden posts can be deployed for about half the cost at ~$15 for the growing season and with minimal installation effort. Captures in pyramid traps and clear sticky traps are strongly correlated as well. A current project aimed at translating the trap-based treatment threshold created with the black pyramid traps and experimental lures to commercially available Trece lures and sticky traps with strong preliminary results. In addition, other trap designs are also being investigated to ensure we see strong grower adoption ultimately.
As these tools reach a stage of refinement and commercial availability, it is anticipated that Extension programs will promote adoption and implementation. That said, we do have some growers that have adopted pheromone-based tools, though below our original performance target. We have a number of other growers still working with us on refinement of these tools, but these are still in experimental development.
And finally, with the spread of the Asian parasitoid, Trissolcus japonicus, and probably because of native predators and parasitoids also attacking BMSB, we are also seeing lower populations of BMSB throughout the region. This likely has had an impact on grower perception and adoption as BMSB has not posed the same threat it did just 5 years ago. Moreover, fewer sprays are necessary because of these lower populations. As part of the SARE and other associated projects, growers have learned a great deal about BMSB natural enemies and the importance of their presence for long-term sustainable management of this invasive species.
Additional Project Outcomes
Building upon what we learned in the BMSB SARE project, we received additional funding from the Ministry of Primary Industries New Zealand ($180,644) to refine pheromone-based tools for monitoring and biosurveillance. We received $110,933 as part of a USDA-NIFA SCRI project for BMSB where we are focusing on refining decision support tools and attract and kill technology for BMSB and in particular, incorporating long-lasting insecticide treated netting. Finally, we received funds from the USDA-ARS Areawide program ($371, 278 annually for 5 years) to work on an areawide biointensive management plan to reduce impacts from BMSB across the agro-urban interface.
In 2017 and 2018, we have demonstrated that by replacing insecticide sprays with long-lasting insecticide treated nets on pheromone-baited apple trees, we eliminate the need for insecticide applications and protect apple fruit from injury at least as well and in some cases better than standard grower programs. Pheromone lures used in these trials are now commercially available as well. It appears we are poised for a grower-friendly and economical attract and kills system for BMSB in apple, though more use and experience by growers, crop consultants and Extension personnel will be necessary to enhance adoption of this technology.
The research conducted by our group was highlighted in the above article and blog post.
While we have made progress on development of pheromone-based tools for BMSB and growers are very interested in using them, we don't have a good assessment of adoption due to: 1) companies still refining pheromone lures in terms of efficacy and price; 2) trap refinement by researchers; and 3) demonstrated utility over a longer period of time. We anticipate that as more growers and crop consultants learn more about these refined tools and how they work based on the recommendations from the research community , they will permanently adopt them. Currently, 70% of the growers that participated in this project are still using pheromone-based tools on their farms for BMSB, but with the assistance of Research and Extension personnel.