Item No. 1 of 1

INVESTIGATOR: Bushmann, S. L.

PERFORMING INSTITUTION:
UNIVERSITY OF MAINE
ORONO, MAINE 04469

AN ECONOMIC ANALYSIS OF WILD BEE POLLINATION IN LOWBUSH BLUEBERRY PRODUCTION.

NON-TECHNICAL SUMMARY: The purpose of this project is to determine the relative economic values of wild bee pollinators and commercial honeybees in lowbush blueberry production for individual Maine farms. The lowbush blueberry requires insect pollination in order to set fruit. Most farmers rent colonies of the non-native honeybee for pollination services, but wild, native bees are also effective pollinators. This project aims to provide growers with the means to assess the pollination needs of individual fields and to understand the levels of pollination possible if honeybees are not available. In order to achieve these goals, the relative abundance and species diversity of native bees found foraging on blueberry flowers will be determined. This information, along with crop yield, will be used to calculate the economic value of native bees as a community and how much value to attribute to honeybees and common native bee groups. Native bee abundance and diversity will also be examined in relation to field characteristics and farm management practices. Workshops and on‐farm trainings will provide farmers the means to assess their pollination needs and develop a sustainable pollination strategy based upon use of honeybees and/or native bees.

OBJECTIVES: The purpose of this project is to determine the relative economic value of native bee pollinators and commercial honeybees in lowbush blueberry production. Workshops and on‐farm trainings will provide farmers the means to assess their pollination needs and develop a sustainable pollination strategy based upon use of honeybees and/or native bees. Objective 1: Assess native bee contribution to pollination when honeybees are stocked in a field. Objective 2: Determine factors that affect the relative abundance and diversity of native bees in blueberry fields. The diversity and relative abundance of native bees found in and around 16 blueberry fields will be determined by trapping and actively catching bees from any species of flower found in association with the blueberry field. Each field will be described according to physical characteristics, farm management, percent of non‐blueberry flowering plant, composition of non‐crop flowering plant community, percent fruit set, and yield. Bee trapping and floral analysis will take place during blueberry bloom for both years of the project. Farm management and yield data will be collected through interviews with the growers after harvest. From these results, bee species lists and bee family guides will be compiled for farmers. From these lists and from the flower constancy data farmers at workshops can be taught to identify key blueberry bee pollinator groups on their farms. Objective 3: Determine the economic value of native bees in each field. Farmers will be able use the results of this part of the project when making management decisions as I will provide the economic analysis for each individual field. A farmer‐friendly version of the models (calculations) will be developed in concert with the farmers so that practical useful products will result. All data will be made available to growers by Jan. 1 of the winter following the field season. Expected outcomes for Objective 3: A per field value for the economic value of the current native bee community and a per field value for the economic value of selected native bee genera; a per field value for the economic value of honeybees; a semi‐validation of economic models. Objective 4: Develop grower training for sustainable pollination strategy decision making. Over the course of the project, I will initiate on‐going communication with the growers including surveys, individual interviews, on‐site workshops and trainings, and dissemination of the project results and descriptions through newsletters and public presentations. Expected outcome for Objective 4: A population of farmers who feel confident to evaluate the native bee communities (not to species level, but to pollinator group) on their farms and to potentially use that information when making management decisions. Participating farmers can use the results of this part of the project to trace and evaluate their own experiences and changes in knowledge. Ideally, farmers will be willing to share and transfer their learning with other non‐participating farmers.

APPROACH: The purpose of this project is to determine the relative economic value of native bee pollinators and commercial honeybees in lowbush blueberry production. Workshops and on‐farm trainings will provide farmers the means to assess their pollination needs and develop a sustainable pollination strategy based upon use of honeybees and/or native bees. Objective 1: Assess native bee contribution to pollination when honeybees are stocked in a field. Sixteen fields located in Maine will be selected. The proportion of native bees that forage on blueberry will be determined by counting bees that are found in square meter plots. All bees visiting the flowers will be categorized as honeybee, bumblebee, or other native bee. The species composition of the native bee communities will be determined by capturing all native bees visiting blueberry flowers. In each field bees will be actively caught with nets or cups. The bumblebee segment of the community will be quantified by visual counts. I will also determine species composition using the passive method of trapping with soapy‐water filled "bee bowls". This second method will be employed to avoid an underestimate of the very small cryptic native bees. Every native bee and honeybee collected will be frozen before being pinned, labeled, and identified to species. Objective 2: Determine factors that affect the relative abundance and diversity of native bees in blueberry fields. Each field will be described according to physical characteristics, farm management, percent of non‐blueberry flowering plant, composition of non‐crop flowering plant community, percent fruit set, and yield. Bee trapping and floral analysis will take place during blueberry bloom for both years of the project. Farm management and yield data will be collected through interviews with the growers after harvest. Objective 3: Determine the economic value of native bees in each field. Adapting a published equation to calculate an estimate of the economic value of native bees and published pollination rates of five bee genera, I will determine the economic value of native bees as a whole and the value of the separate genera. Objective 4: Develop grower training for sustainable pollination strategy decision making. Each grower will be asked to participate by agreeing to at least two phone interviews, the sharing of financial data and production practices, and the completion of three surveys. Over the course of the two‐year project, each participating grower will receive two newsletters that summarize the known results. Included with the newsletter will be any information pertinent to the individual grower, including information about the economic value of native bees calculated for their farm. Surveys will evaluate a grower's basic knowledge or understanding about bees and a grower's understanding about how farming or other human activities can affect bee populations. I will be evaluating changes in the grower's response as indication that participation as a participating farmer has proven to be an educational experience.

PROGRESS: 2011/08 TO 2014/07
Target Audience: The target audience reached while working towards Objective 4 included extension researchers and lowbush blueberry growers of Maine and the Canadian Maritimes. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? During this reporting period, this project has supported the Project Director while completing a dissertation at the University of Maine. (Completed December 2013). How have the results been disseminated to communities of interest? Publication of a dissertation. Other papers in preparation. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

IMPACT: 2011/08 TO 2014/07
What was accomplished under these goals? Accomplishments pertaining to these goals were addressed in a previous report. No further work was accomplished under these goals. The exception being that additional work towards Objective 4 was accomplished in the fall of 2013. On October 25, 2013, I presented key findings of this research with a talk entitled "Farm management and landscape factors that impact wild bee diversity and abundance in the Maine lowbush blueberry agroecosystem" at the Wild Blueberry Research and Extension Workers meeting held in Bangor, Maine. This meeting is attended by both extension workers and growers.

PUBLICATIONS (not previously reported): 2011/08 TO 2014/07
Type: Theses/Dissertations Status: Published Year Published: 2013 Citation: Bushmann, S.L. 2013. Wild bee (Hymenoptera: Apoidea) communities associated with the lowbush blueberry agroecosystem of Maine. PhD Dissertation, Univ. Maine, Orono, ME, 137 pp.

PROGRESS: 2012/08/01 TO 2013/07/31
Target Audience: The target audience of this project is the Maine Lowbush blueberry growers. This group represents about 500 growers representing various types of production from organic to high input conventional production. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? This project has provided the PD significant training and professional opportunities including (1) further training in native bee identification provided by an expert from USGS and (2) the completion of a doctoral dissertation along with a public defense seminar given on October 18, 2013. Further professional development has included 10-minute research talks given at (1) the Entomological Society of America annual meeting in Nov. 2012 and (2) an international Canadian/American meeting of lowbush blueberry growers and researchers in Oct. 2013. This research has also provided the PD opportunities to develop collaborations with bee researchers from other Universities and collaborations with graduate students and other researchers from other science departments within the University of Maine. The goal of these collaborations is joint authorship publications. How have the results been disseminated to communities of interest? The results have been disseminated to the communities of interest through (1) communications with individual growers that detailed the native bee species diversity found in their fields and included other data collected in the field such as fruit set and soil analyses, (2) a report about native bee biology that was part of a series of reports published on the University of Maine wild blueberry blog, and (3) a presentation given to an international group of Canadian and American growers and researchers that provided findings concerning Objective 2. What do you plan to do during the next reporting period to accomplish the goals? During this next reporting period 2-3 papers will be submitted to peer reviewed journals for publication and additional reports detailing the economic analysis of native bee pollination will be prepared for Maine lowbush blueberry farmers and growers.

IMPACT: 2012/08/01 TO 2013/07/31
What was accomplished under these goals? Objective 1: This research has documented foraging native bees in 40 study sites that are representative of smaller blueberry fields common in Maine blueberry production. Bumblebee and all other native bee foraging is independent of honeybee foraging. Bumblebee foraging rates were shown to be positively related to fruit set while total native bee foraging rates were positively related to crop yield and crop value. Furthermore, bumblebee and total native bee foraging rates had a greater impact upon fruit set and yield than honeybee foraging. The conclusion is that native bees that freely forage in the blueberry fields provide a significant level of pollination services for the Maine blueberry farmer. Objective 2: This research has determined that native bee abundance is sensitive to habitat. Native bee abundance declines with increasing field size and increases in those fields with greater proportions of surrounding landscape features that provide forage and nest sites. This research found no evidence of farm managment impacts on native bee diversity or abundance. Objective 3: This research has determined that on a per field basis, native bee foraging contributes 7-100% of the pollination services. The pollination services not provided by native bees are provided by honeybees. Farmers increasingly use honeybees as field size increases. Objective 4: Three important communications with farmers and growers took place during this reporting period. These include (1) communications with individual growers that detailed the wild bee species diversity found in their fields and included other data collected in the field such as fruit set and soil analyses, (2) a report about native bee biology that was part of a series of reports published on the University of Maine wild blueberry blog, and (3) a presentation given to an international group of Canadian and American growers and researchers that provided findings concerning Objective 2.

PUBLICATIONS: 2012/08/01 TO 2013/07/31
No publications reported this period.

PROGRESS: 2011/08/01 TO 2012/07/31
OUTPUTS: A goal of this project is to document the diversity and abundance of the wild bees found in and around blueberry fields. In meeting this goal, 1550 bees representing 92 species, 13 genera and 5 families were caught and pinned during the Spring and Summer of 2011. The identification of the majority of the bees were determined or confirmed by an expert from the United States Geological Survey. The remainders were taken to a class for the identification of bees of the genus Lasioglossum held at the University of Massachusetts, Amherst in March 2012. Another goal of this project is to determine which wild bees contribute to blueberry pollination. In 2011, 186 bees were caught on blueberry flowers. Over 50% of these bees are of three species: Andrena carlini, Andrena vicina, and Andrena carolina. Current work in progress will determine if conservation of these bees will be of economic importance to farmers. Additional fieldwork during the Spring and Summer of 2012 caught about 2300 bees from 16 new fields managed by ten farmers new to this project. These bees are currently being identified to species. Another study was aimed at determining the level of bumble bee Nosema disease. The primary objective was to determine if the prevalence of Nosema bombi infection is higher for wild bumblebees (Bombus spp.) caught in lowbush blueberry growing areas with a history of commercial bumblebee use than for bumblebees caught in areas without a history of commercial bumblebee use. Additionally, we wished to determine relative Bombus species abundances and diversity in blueberry growing regions. Over two years we caught, identified to species, and dissected 767 bumblebees. Light microscopy revealed overall infection levels of 5.48%. The history of commercial bumblebee use had no relation to infection levels. Bumblebee species diversity and field location had significant relationships to infection (r2 adjusted = 0.265; species diversity F(1,22) = 6.848, P = 0.016; field region F(1,22) = 5.245, P = 0.032). The absence or presence of one species, Bombus terricola, appears to determine the relationship between species diversity and infection. The data show B. terricola declining in sampled regions and almost half of the collected B. terricola were infected with Nosema. The commercial species, B. impatiens, shows an increase in abundance, but with a 6.9% proportion infection. Molecular confirmation of the infecting species was ambiguous, suggesting a need for future clarification of the infecting species. PARTICIPANTS: Other individuals that worked on this project during the past year are Dr. Francis Drummond in the School of Biology and Cooperative extension at the University of Maine and Dr. David Yarborough, Cooperative Extension at the University of Maine. The opportunities for professional training from this project were three. The first was training in plant taxonomy. This was accomplished by taking a field plant taxonomy class at Eagle Hill Nature Center. Training in Bee taxonomy and identification was accomplished by visiting the laboratory of Dr. Sam Droege. I visited this lab three times during 2012 and he helped me identify my bee species. The third professional development opportunity was developing a blog for growers on pollination. I set this up during the summer of 2012 and I have submitted several informational items for this blog. TARGET AUDIENCES: The target audience of this project is the Maine Lowbush blueberry growers. This group represents about 500 growers representing various types of production from organic to high input conventional production. Efforts. I presented two pollination workshops to blueberry growers in 2012. These workshops were held in growers fields and were organized by the University of Maine Cooperative Extension. PROJECT MODIFICATIONS: None

IMPACT: 2011/08/01 TO 2012/07/31
This project requires cooperation from participating farmers and requires frequent communication. Letters detailing results from individual fields are mailed to the farmers, blog posts with general information are posted at the University of Maine extension blueberry blog, and the work has been presented at grower's meetings. In total, since 2010, this project has required the cooperation of 18 different farmers and managers.

PUBLICATIONS: 2011/08/01 TO 2012/07/31
Bushmann, S.L., F. A. Drummond, L. A. Beers, and E.Groden. 2012. Wild bumblebee (Bombus) diversity and Nosema (Microsporidia: Nosematidae) infection levels associated with lowbush blueberry (Vaccinium angustifolium) production and commercial bumblebee pollinators. Psyche 2012, Article ID 429398, 11 pp., doi:10.1155/2012/429398.