The Enhancement of Wild Bees (Hymenoptera: Apoidea) For
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The University of Maine DigitalCommons@UMaine Electronic Theses and Dissertations Fogler Library Summer 8-7-2015 The nhE ancement of Wild Bees (Hymenoptera: Apoidea) For Pollination Security Eric M. Venturini University of Maine, [email protected] Follow this and additional works at: http://digitalcommons.library.umaine.edu/etd Part of the Agricultural Economics Commons, Agricultural Science Commons, Agronomy and Crop Sciences Commons, Apiculture Commons, Biodiversity Commons, Botany Commons, Entomology Commons, Fruit Science Commons, Horticulture Commons, and the Laboratory and Basic Science Research Commons Recommended Citation Venturini, Eric M., "The nhE ancement of Wild Bees (Hymenoptera: Apoidea) For Pollination Security" (2015). Electronic Theses and Dissertations. 2339. http://digitalcommons.library.umaine.edu/etd/2339 This Open-Access Thesis is brought to you for free and open access by DigitalCommons@UMaine. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of DigitalCommons@UMaine. THE ENHANCEMENT OF WILD BEES (HYMENOPTERA: APOIDEA) FOR POLLINATION SECURITY By Eric Matthew Venturini B.S. University of Maine, 2006 A THESIS Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Science (in Ecology and Environmental Science) The Graduate School The University of Maine August, 2015 Advisory Committee: Francis A. Drummond, Professor of Insect Ecology, Advisor Alison C. Dibble, Assistant Research Professor of Pollination Ecology Aaron K. Hoshide, Adjunct Assistant Professor of Economics Lois Berg Stack, Professor of Sustainable Agriculture THESIS ACCEPTANCE STATEMENT On behalf of the Graduate Committee for Eric Venturini I affirm that this manuscript is the final and accepted thesis. Signatures of all committee members are on file with the Graduate School at the University of Maine 42 Stodder Hall, Orono, Maine. Dr. Francis Drummond, Professor of Insect Ecology Date ii © 2015 Eric M. Venturini All Rights Reserved iii LIBRARY RIGHTS STATEMENT In presenting this thesis in partial fulfillment of the requirements for an advanced degree at the University of Maine, I agree that the Library shall make it freely available for inspection. I further agree that permission for “fair use” copying of this thesis for scholarly purposes may be granted by the Librarian. It is understood that any copying or publication of this thesis for financial gain shall not be allowed without my written permission. Signature: Date: THE ENHANCEMENT OF WILD BEES (HYMENOPTERA: APOIDEA) FOR POLLINATION SECURITY By Eric Matthew Venturini Thesis Advisor: Dr. Francis A. Drummond An Abstract of the Thesis Presented in Partial Fulfillment of the Requirements for the Degree of Master of Science (in Ecology and Environmental Science) August, 2015 The acreage of pollinator-dependent crops continues to expand across the globe. Simultaneously, honey bee hives – an annually rented commodity that growers rely on – are more expensive every year and in some cases, scarce. In response, pollinator-dependent growers seek alternative pollinators. One approach is installing bee pasture on farms, a strategy that enables systems-based farmers to become in-situ farm-scale habitat managers. This thesis first presents a review of the literature on bee pasture plantings and provides a brief overview of some methods for assessing their impacts on the pollinator community. There are three major gaps in current bee pasture research. First, can bee pasture actually enhance bee populations? Second, what ratio of bee pasture to crop is required to significantly increase pollination services in a crop field? Last, research that assesses that attractiveness of easily established, phenologically diverse region- and crop-specific flowers that are unlikely to become weedy in crop fields is still rare. The second chapter of this thesis presents the results of a comprehensive two-year study of bee pasture plantings within the context of New England’s wild lowbush blueberry agroecosystem. Using a randomized complete block design I investigate the effects of nurse crops and mowing regimes on bee pasture establishment success in terms of floral density and species diversity. Three types of bee pasture (clovers, wildflowers, and naturally regenerating margins) were installed at four replicated sites in Maine. Bee pastures were compared in terms of both floral density and insect visitation. Bumble bees were collected at the four treatment sites, and the species’ group composition of their pollen loads were compared with those of bumble bees collected in three control sites. Similar patterns of visitation to bee pasture are apparent among years. Analysis of visitation in the second year alone suggests that naturally regenerating agricultural margins supported 3-4 times fewer wild bee pollinators than other treatments (2 = 5.808, P = 0.055). These differences are significant when wild bees are parsed into social and solitary groups. Social bees utilize clover plantings at a significantly greater rate than solitary bees (2 = 7.269, P = 0.026) and solitary bees utilize wildflower plantings over clover and naturally regenerating plots (2 = 7.423, P = 0.024). On average, across all blueberry fields adjacent to sown bee pasture, bumble bee pollen loads contained 37% bee pasture pollen. Our findings suggest that in lowbush blueberry fields, even relatively small sown flowering strips can provide over 1/3 of the dietary pollen for bumble bees, clover plantings are highly utilized by bumble bees, and wildflower plantings show great potential to provision resources for solitary bees. ACKNOWLEDGEMENTS I am greatly indebted to the growers Tod Cheney, Holly Bixby, and Danner and Dewey Curtis, who not only allowed me to install bee pasture plantings on their properties but even helped me to do so. Dell Emerson, Paul Sweetland, David and Ellen Simmons, and Paul Allen allowed me and my student technicians to freely access and sample their fields. Doug VanHorn and Peter Collins voluntarily installed my experimental wildflower mix on their own blueberry farms and granted me access for additional sampling. Jeff Brann, Josh Stubbs, and Chris McManus of The University of Maine’s research facility, Blueberry Hill Farm in Jonesboro, Maine were immeasurably helpful and provided equipment, labor, space, advice, and a venue for talking to growers. Likewise, Joe Cannon, farm manager at Rogers Farm Forage and Crop Research Facility in Stillwater, Maine provided an additional research plot, the equipment, and labor to install and maintain it. He also played the mandolin, wore a zoot suit, and ensured that we worked in the safest environment. My full-time student field technicians Audrey Maddox, Sarah Watts, and Margaret McCullough went well beyond the job description working long days and providing endless energy and song that fueled the project’s success. I also thank the large number of other student technicians that helped in various ways throughout the course of the project including Sadie Wight, Jacob Bailey, Connor McCormic, Haley Boddington, Nick Peterson, and Wesley Woods. Two High School students in the EPSCOR program provided additional help including Billy Desisto and Nathan Frederick. The latter explored the role of kleptoparasites in blueberry field bee communities. I extend great personal thanks to my wife Julia McGuire and my parents Glenn and Marian Venturini for their unending support in every way. Special thanks go to my outstanding advisor and role model Dr. Francis Drummond whose commitment to growers, sustainable agriculture, and students knows no bounds. My committee members Dr. iv Aaron Hoshide, Dr. Alison Dibble, and Dr. Lois Stack provided endless encouragement, feedback, and advice. I also called on the expertise of Dr. Sara Bushmann, Dr. John Skinner, Dr. Anne Averill, Dr. Brett Blaauw, and Dr. Rufus Isaacs. Sam Droege provided extraordinary expertise, guidance, and inspiration while confirming or correcting my bee specimen identifications. Dr. Alison Dibble taught me much about plant identification and identified hundreds of plants throughout this project. This research was made possible by funding from the United Stated Department of Agriculture and of course, The University of Maine. Diane Wilson of Applewood Seed Company provided free wildflower seeds and advice both in seed mix design but also in establishment methodology. Thank you all. v TABLE OF CONTENTS ACKNOWLEDGEMENTS .............................................................................................................. iv LIST OF TABLES ...........................................................................................................................ix LIST OF FIGURES.......................................................................................................................... x CHAPTER 1: BEE PASTURE FOR POLLINATOR HABITAT ENHANCEMENT: A REVIEW ...................... 1 1.1. Background ................................................................................................................ 1 1.1.1. Agricultural Intensification .................................................................................... 2 1.1.2. Externalities: Who Pays? ....................................................................................... 2 1.2. The Pollination Problem .............................................................................................. 3 1.2.1. Increases in Pollinator-dependent Crops ..............................................................