Building attract-and-kill systems for management of the brown marmorated stink bug in apple orchards

Building attract-and-kill systems for management of the brown marmorated stink bug in apple orchards

Summary

The project aims to develop an attract-and-kill program against brown marmorated stink bug (BMSB) for adoption by commercial apple growers in the mid-Atlantic region. Before the field season, we administered a survey to tree fruit growers in the mid-Atlantic, and received baseline data on management practices from 228 respondents located in New Jersey, West Virginia, Virginia, Maryland, and Pennsylvania. We collaborated with 10 growers from these same states to compare management of BMSB using attract and kill technology and standard management practices in commercial orchards and to utilize pheromone-baited traps to guide specific management decisions. We created a project blog (http://williammorrison.wix.com/sare-blog), video about attract-and-kill principles on YouTube (450 views), and the research group has had 4 teleconferences, and two in-person meetings to discuss coordination of outreach and research efforts for the project. Finally, the results generated by this project have been presented at 2 national and regional academic and 2 Extension conferences and meetings.

Objectives/Performance Targets

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.

Accomplishments/Milestones

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. Completed by March 2015. We exceeded this milestone by having 228 respondents to our survey to establish baseline information regarding BMSB management practices.
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. Completed February 2015. This information was conveyed at 13 grower meetings in five states reaching an estimated 400+ growers.
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. Completed April 2015. We had a total of 228 respondents to the survey and 10 growers agreed to collaborate in performing on-farm trials to test attract-and-kill technology during the 2015 growing season, meeting the expected target.
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. Completed April-October 2015. In addition to collaborating with 10 growers in their commercial orchards, we rendered team support in the deployment of experiments, and season-long management input based on pest pressure in orchard blocks.
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). Completed August 2015. We organized a field day in West Virginia, where we conveyed recent findings from the ‘attract-and-kill and other concurrent BMSB projects. We also presented at field days in Pennsylvania, Virginia, and New Jersey, collectively reaching 300+ tree fruit growers in the mid-Atlantic. In New Jersey, we garnered additional media attention in August for our attract-and-kill project from the industry trade publication, The American Fruit Grower (http://www.growingproduce.com/fruits/sustainable-options-for-brown-marmorated-stink-bug-control/).

Impacts and Contributions/Outcomes

In the winter of 2015, we collected baseline data from commercial apple growers on BMSB management practices. We distributed the survey at 13 regional and state Extension meetings, and reached an estimated audience of 400+ growers in five mid-Atlantic states. We had 200+ growers return the survey, allowing us to assess current practices for managing BMSB. Our findings indicate that 86% of apple growers have had problems with BMSB on over 10,800 acres. Of these growers, 76% regularly apply insecticides for BMSB, and over half of growers have reported secondary pest outbreaks due to these broad-spectrum applications. Importantly, 80% of growers indicated that they are interested in using attract-and-kill to manage BMSB and 65% of growers are either interested in using, have already used, or plan to use baited pyramid traps to monitor BMSB pressure on their farms.

            In the spring of 2015, the research team collaborated with 10 growers to implement side-by-side comparisons of attract-and-kill technology with standard management tactics for BMSB in apple orchards. Pheromone-baited traps were deployed in both attract-and-kill and comparison blocks to guide BMSB management decisions. These trials ran concurrently in five states from June to late October (in some cases). We sampled fruit at three points in the season: early-and mid-season and at harvest (cultivar-dependent date). Throughout the season, there was significantly less severe damage to fruit harvested in our attract-and-kill block compared with the grower standard. 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 the number 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. Each collaborating grower is providing spray records for the season to provide further information as to the cost-benefit of using attract and kill compared with standard management practices.

            Growers have received the project with optimism, and our collaborators all have agreed to continue the study for another year. We have received positive feedback at grower meetings when we have presented our fruit harvest data and growers have indicated repeatedly that they would like to use pheromone-based tools to guide management of BMSB.

            After the first year, we have found that we can reduce the percentage of trees in an orchard treated with insecticides by 97% using attract-and-kill. This translates to a significant reduction in costs associated with insecticide treatment, lowering costs of application from ~$30-100 per acre in the grower standard to ~$6-20 per acre in the attract-and-kill treatment. In attract-and-kill blocks, while mite populations were comparable to the grower standard, the wooly apple aphid population was reduced over 4-fold. Specifically, there were 0.3 aphids per three minute timed count in the attract-and-kill blocks compared to 1.4 aphids in the grower standard blocks, suggesting that secondary pest outbreaks may be less frequent.

            One issue that we encountered during the first year was the cost of the pheromone. However, this was due to the fact that a single company was producing pheromone at that time. The experimental cost was estimated to be $1500/acre for attract and kill, but is expected to decrease over time.   This is due to the fact that at least two other companies have begun to manufacture pheromone and improve synthetic pathways for production. In addition, at least 5 companies are interested in producing pheromone lures for monitoring BMSB (at ~$5-7/lure) and two companies are interested in producing higher loading attract and kill lures (no cost available yet).

            Despite this challenge, we are now positioned well to communicate the benefits and potential costs of using pheromone-baited traps to monitor and attract-and-kill technology to manage BMSB to growers through winter Extension meetings and IPM schools. We will be administering a second round of the survey, and determining change in attitudes between the first and second year.

Collaborators: