Bee Protection Protocols for Oregon Vegetable and Clover Seed.

Progress report for SW19-903

Project Type: Research and Education
Funds awarded in 2019: $349,971.00
Projected End Date: 08/31/2022
Grant Recipient: Oregon State University
Region: Western
State: Oregon
Principal Investigator:
Dr. Andony Melathopoulos
Oregon State University
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Project Information

Abstract:

Pests and diseases of pollinator-dependent crops can lead to damage or total crop loss, particularly if left untreated at or close to bloom. But bloom is also the time that beekeepers move honey bee colonies to pollinating these crops, leading to the prospect of the colonies being exposed to pesticides. The challenge of maintaining high crop yield without impact honey bee colony health is a challenge across the US and this prompted the Environmental Protection Agency to encourage state’s to develop voluntary Managed Pollinator Protection Plans (MP3s) to better coordinate the activity of pesticide applicators and beekeepers. Although MP3s exist in most states, they can struggle to have impacts on pollinator health because they: (a) are based on best management practices (BMPs) may be too general to be meaningful to local growers and beekeepers; (b) are poorly articulated with extension activities, thereby being largely left to stakeholders to voluntarily adopt with little support; (c) lack metrics to measure progress towards reduced exposure of bees; and, (d) lack important tools that growers use to mitigate pesticide exposure around bees, particularly well-specified pesticide residual toxicity times. These shortcomings weaken the capacity of the MP3s to bring about improved bee stewardship.

Our proposal directly addresses these challenges by developing pilot Bee Protection Protocols for two high value seed crops in Oregon. The Protocols provide crop-specific guidance on how to manage pests in ways that minimize pesticide exposure to honey bees. The Protocols will be built around new data, generated through this project, on residual toxicity of pesticides used in these crops under different environmental conditions. Moreover, the Protocols will be shored up through extensive Extension and training activities that include evaluation methods that will track knowledge and adoption of the Protocols. Finally, through surveys of commercial beekeepers in Oregon we will be able to measure the impact of the Protocols towards increasing communication with growers and crop consultants and decreasing pesticide exposure to their bees.   

Project Objectives:
  1. Residual Toxicity – Sources of Variation. We would determine the sources of variation in the current assay for residual toxicity and determine the protocol that most reflects field conditions by 2020. These results would be used by growers, crop consultants, beekeepers and regulators to identify the types of pesticides whose residual toxicity values would be vulnerable to change according to environmental conditions.  
  2. Residual Toxicity Estimates. We would establish 3h, 6h, 8h, 1d and 5d residual toxicity values for all widely used fungicide and insecticide treatments applied at bloom, as well as common tank mixes by 2021. These values would enable growers, crop consultants, beekeepers and regulators in making pesticide selections that minimize impacts to honey bees.
  3. Bee Protection Protocols. We would expand on an existing vegetable seed protocol by 2021 and create a new protocol for the Oregon clover seed industry by 2020. These Protocols would increase levels of communication among growers, crop consultants and beekeepers around pesticide use during pollination and reduce pesticide exposure of bees.  
  4. Extension and Training.  We would deliver two 60-minute face-to-face trainings on the Bee Protection Protocols to the seed growers and beekeepers, and two day-long workshops covering advanced topics in bee stewardship on farms in 2019 and 2020. We would also provide two YouTube videos and four podcasts that show case growers who have achieved excellence in stewardship by 2021. Finally, we would produce two new Extension publications, revise an existing publication and produce two infographic postcards.  This training would translate into reduced pesticide exposure of bees in vegetable and clover seed.
  5. Measuring Increased Communication and Reduced Pesticide Exposure. We would implement grower and beekeeper surveys to assess the effectiveness of the protocols to improve communication and reduce exposure.

Cooperators

Click linked name(s) to expand
  • Prof. Nicole Anderson - Technical Advisor (Educator and Researcher)
  • Prof. Nicole Anderson - Technical Advisor (Educator and Researcher)
  • Prof. Nicole Anderson - Technical Advisor (Educator and Researcher)
  • Dr. Kristine Buckland (Educator and Researcher)
  • Dr. Kristine Buckland (Educator and Researcher)
  • George Hansen - Producer
  • Dave Nofziger - Producer
  • Mike Vandehey - Producer
  • Harry Vanderpool - Producer (Educator)
  • Harry Vanderpool - Producer (Educator)
  • Bob VanderZanden - Producer

Research

Hypothesis:
  1. Residual Toxicity – Sources of Variation. We would determine the sources of variation in the current assay for residual toxicity and determine the protocol that most reflects field conditions by 2020. These results would be used by growers, crop consultants, beekeepers and regulators to identify the types of pesticides whose residual toxicity values would be vulnerable to change according to environmental conditions.  
  2. Residual Toxicity Estimates. We would establish 3h, 6h, 8h, 1d and 5d residual toxicity values for all widely used fungicide and insecticide treatments applied at bloom, as well as common tank mixes by 2021. These values would enable growers, crop consultants, beekeepers and regulators in making pesticide selections that minimize impacts to honey bees.
  3. Bee Protection Protocols. We would expand on an existing vegetable seed protocol by 2021 and create a new protocol for the Oregon clover seed industry by 2020. These Protocols would increase levels of communication among growers, crop consultants and beekeepers around pesticide use during pollination and reduce pesticide exposure of bees.  
  4. Extension and Training.  We would deliver two 60-minute face-to-face trainings on the Bee Protection Protocols to the seed growers and beekeepers, and two day-long workshops covering advanced topics in bee stewardship on farms in 2019 and 2020. We would also provide two YouTube videos and four podcasts that show case growers who have achieved excellence in stewardship by 2021. Finally, we would produce two new Extension publications, revise an existing publication and produce two infographic postcards.  This training would translate into reduced pesticide exposure of bees in vegetable and clover seed.
  5. Measuring Increased Communication and Reduced Pesticide Exposure. We would implement grower and beekeeper surveys to assess the effectiveness of the protocols to improve communication and reduce exposure.
Materials and methods:

Objectives 1 and 2: Owing to poor clover and alfalfa establishment, which was compound by covid-19-related disruptions, we were unable to compare residual toxicity values among different crops, but were able to develop estimates of the two mostly widely used insecticides around crop bloom on radish seed (bifenthrin and cyantraniprole) across two seasons.  We followed the experimental protocol outlined by EPA in “Honey Bee Toxicity of Residues on Foliage” (OCSPP 850.3030), in which we treated 1m2 plots of radish at the bolting stage. Notably, the stage of plant treatment was determined in consultation with our advisory committee, because this most paralleled the practice outlined in the Bee Protection Protocol (objective 3). The advisory committee recommended including a treatment with bifenthrin at the lowest label rate, as it is reported in OSU Extension documents as having lower residual toxicity to honey bees.  The pesticide residues were left to weather on the leaves for set intervals of time before we harvested the plant material and placed the treated foliage in cages filled with adult worker bees. The assay involved counting the number of dead bees in the cage after 24h of exposure to the weathered residues. The treated foliage were harvested at 3, 6, 24 and 96 h post-application. Our radish trials were conducted both in 2019 and 2020. In addition, we modified the protocol to determine the amount of dislodgable pesticide residue remaining on the leaves.

Objective 3: We held meetings with the Specialty Seed Growers of Western Oregon (SSGWO) and Oregon Clover Commission (OCC), as well as with OSU Extension, crop consultants and delegates from the Oregon State Beekeepers Association to develop Bee Protection Protocols focused on issues of: (a) colony strength, timing of movement of colonies in and out of fields and beekeeper access to colonies under contract; (b) grower/beekeeper pest management practices during bloom; and, (c) grower/beekeeper communication. 

Objective 4: We delivered a face-to-face training with SSGWO members in January 2021 and developed a public facing a You-Tube video on the clover seed Bee Protection Protocol. We have produced 1000 seed packs highlighting the Bee Protection Protocols and we are distributing them to the public this spring through the OSU Master Gardeners. 

Objective 5: SSGWO members were surveyed in January 2021 to measure adoption of the Bee Protection Protocols. 

Research results and discussion:

Objectives 1 and 2. We confirmed the long residual toxicity of bifenthrin to honey bees on radish seed and demonstrated in 2019, that this long residual toxicity extended to the low rate of bifenthrin (Figure 1). This result was consistent across two years, suggesting little environmental variation in residual toxicity of this product (note, the low rate was only tested in 2020). In contrast, cyantrailiprole demonstrated very little residual toxicity relative to leaves harvested from plots that were not treated with insecticide. The finding with cyantrailiprole was notable, as EPA has indicated this product has a long residual toxicity (in the Directions for Use on Exeril, the cyantrailiprole product labelled for radish seed, indicate that the product cannot be applied until “flowering complete”). 

Figure 1. Box and whisker plot of the acute toxicity of two insecticides to honey bees caged on treated radish leaf after being weathered for 3, 6, 25 or 96h, relative to leaves from untreated control plots.

Given the unexpected result with the cyantrailiprole, we modified our proposal to resolve question of concern to the SSGWO, specifically, whether:  (a) cyantrailiprole’s lack of toxicity was associated with the product breaking down on the leaf surface and (b) whether the two insecticides applied at the bolting phase would be expressed in flowers at bloom. We observed that cyantraniliprole remained on leaves at 3h at levels that exceeded bifenthrin, suggesting that the product may have been present on the leaf tissue but not bioavailable to bees on contact (Figure 2, note cyantraniliprole was only tested at 3h). We also observed that bifenthrin remained at relatively consistent levels across the experiment (1-10 ppm), which was consistent with the honey bee residual toxicity bioassay (Figure 1). 

Figure 2. Box and whisker plot of recoverable insecticide residues from radish leaves following 3, 6, 24 and 96h of weathering with bifenthrin (low and high rate) or 3h of weathering cyantraniliprole (high rate), relative to leaves from an untreated control plots. 

There was a marked reduction in the residues detectable in the flowers (Figure 3) compared to residues detected in leaves prior to flowering (Figure 2). 

Fig 3. Box and whisker plot of of recoverable insecticide residues from radish flowers in 2019 at 25% bloom for bifenthrin (low and high rate)  and cyantraniliprole (high rate) relative to flowers from untreated control plots.  

Objective 5. We completed the Oregon Clover Commission Bee Protection Protocol in January 2020. We conducted a follow up survey with growers in the SSGWO in order to measure changes in behavior since the development of the original Bee Protection Protocol in 2018.  Notably, a higher proportion of growers characterized their interaction with beekeepers had become more productive since the Protocols were developed (Table 1). We also found that 64% of growers called their beekeepers around the application of insecticides prior to the delivery of bees for pollination, compared to 45% in 2018.   Surveys confirmed the high reliance on bifenthrin used by growers at the bolting stage, prior to the arrival of bees (78% of the growers indicated bifenthrin was their go-to product for pre-bloom insect pest clean-up sprays). 

Table 1. Percentage of Oregon radish seed growers characterizing their interaction with beekeepers pollinating their crop by the following statements.

 

2018 (n=32)

2021 (n=11)

“Fraught and combative”

0

0

“Okay, but beekeeper makes too many demands”

0

9

“Okay, but there is a lot of miscommunication”

35

9

“Productive – we work through problems.

65

82

 

Participation Summary
350 Farmers participating in research

Education

Educational approach:

The research team developed a Bee Protection Protocol for clover seed production in December 2019-February 2020. The protocol was developed by a team consisting of Ron Quiring (Oregon Clover Commission), Ian Roth (Nutrien), Nicole Anderson (OSU Extension), Denny Thorud (Valley Agronomics), Mike Vandehey (Oregon Clover Commission), Harry Vanderpool (Past President, Oregon State Beekeepers Association), Ramesh Sagili (OSU Extension), Mark Johnson (commercial beekeeper). The protocol was developed into an infographic postcard and an Extension publication is underway.   

Educational & Outreach Activities

1 Curricula, factsheets or educational tools
2 Webinars / talks / presentations

Participation Summary

175 Farmers
25 Ag professionals participated
Education/outreach description:

The Clover Seed and Radish Seed Bee Protection Protocol were presented at the annual meetings of the Clover Commission (Feb 5, 2020) and the Specialty Seed Growers of Western Oregon (Jan 21, 2020). We used electronic clickers to determine current practices used by the growers and to determine the extent of alignment with the practices outlined in the protocol. Finally, we developed seed packs for each industry to be distributed to the public to help promote their Bee Protection Protocol (Seeds for Bees – SSGWO, Clover Seed Pack). Our plan is to distribute 5,000 of these seed packs to the public through the Master Gardeners through the summer, however, this goal may be differed to the summer of 2021 due to covid-19 restrictions. 

Learning Outcomes

Key areas taught:
  • We have measured pre-protocol behavior in 2020 - we will measure change in behavior in subsequent years
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.