NATIVE BEE VISITATION ON FLORIDA NATIVE WILDFLOWERS By KATHARINE D. BUCKLEY A THESIS PRESENTED TO THE GRADUATE SCHOOL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE UNIVERSITY OF FLORIDA 2011 1 © 2011 Katharine D. Buckley 2 To those who knew I was weird and encouraged me to study bugs anyway 3 ACKNOWLEDGMENTS I thank my advisor, Dr. Jamie Ellis, and committee members Drs. Jaret Daniels and Glenn Hall for all their advice and guidance. I thank Dr. David Jarzen for the generous gift of the use of his laboratory, supplies and expertise in palynology. I thank James Colee for helping me with statistics. I also thank my fellow graduate students Eddie Atkinson, Jason Graham, Pablo Herrera, and Dr. J. Akers Pence as well as research technicians Jeanette Klopchin, Mark Dykes, Michelle Kelley, Jonnie Dietz and Ben King for their help and support. I especially thank my family for their love and encouragement of my desire to study bugs, including letting me keep a tarantula in my bedroom. 4 TABLE OF CONTENTS page ACKNOWLEDGMENTS.................................................................................................. 4 LIST OF TABLES............................................................................................................ 7 LIST OF FIGURES.......................................................................................................... 8 ABSTRACT ..................................................................................................................... 9 CHAPTER 1 INTRODUCTION .................................................................................................... 11 2 MATERIALS AND METHODS ................................................................................ 22 General Site Information......................................................................................... 22 Site Preparation and Establishment ................................................................. 23 Site Maintenance.............................................................................................. 24 Vegetation Survey .................................................................................................. 24 Bee Survey ............................................................................................................. 25 Primary Bee Surveys........................................................................................ 25 Supplementary Bee Surveys............................................................................ 26 Pollen Survey.......................................................................................................... 27 Statistical Analysis .................................................................................................. 29 3 RESULT S ............................................................................................................... 43 Overall Bee Attraction to Native Florida Wildflowers............................................... 43 Principle Overlapping Flowers.......................................................................... 43 Spring Time Period........................................................................................... 44 Late Summer/Early Fall Time Period................................................................ 44 Late Fall Time Period ....................................................................................... 45 Wildflower Visitation by Bee Tribe .......................................................................... 45 Apini (Apidae)................................................................................................... 45 Spring time period...................................................................................... 45 Augochlorini (Halictidae)................................................................................... 46 Bombini (Apidae).............................................................................................. 46 Principle overlapping flowers ..................................................................... 46 Late summer/early fall time period ............................................................. 47 Eucerini (Apidae).............................................................................................. 47 Late fall time period.................................................................................... 47 Halictini (Halictidae).......................................................................................... 48 Principle overlapping flowers ..................................................................... 48 Spring time period...................................................................................... 48 Late summer/early fall time period ............................................................. 48 5 Late fall time period.................................................................................... 49 Megachilini (Megachilidae)............................................................................... 49 Principle overlapping plants ....................................................................... 49 Late summer/early fall time period ............................................................. 49 Late fall time period.................................................................................... 50 Xylocopini (Apidae) .......................................................................................... 50 Principle overlapping flowers ..................................................................... 50 Late summer/early fall time period ............................................................. 50 Pollen Washes........................................................................................................ 51 Pollen Wash Means ......................................................................................... 51 Pollen Wash Percentage Likelihood................................................................. 51 Pollen on Bumble Bees .................................................................................... 51 Pollen on Halictus poeyi ................................................................................... 52 4 DISCUSSION ......................................................................................................... 79 Benefits of Wildflower Mixes ................................................................................... 79 Native Bee Use of Wildflower Species.................................................................... 79 Developing a Florida Wildflower Mix That Is Used By Native Bees ........................ 81 Study Limitations .................................................................................................... 83 Further Investigations ............................................................................................. 84 Conclusion .............................................................................................................. 88 LIST OF REFERENCES ............................................................................................... 90 BIOGRAPHICAL SKETCH............................................................................................ 99 6 LIST OF TABLES Table page 1-1 Examples of bee forage studies ......................................................................... 21 2-1 Wildflowers assessed in the study...................................................................... 32 2-2 Wildflower drought tolerance and months of bloom time .................................... 33 2-3 Wildflower sources, % pure seed, % germination rate, and ecotype/source of the wildflowers.................................................................................................... 34 2-4 Grams of wildflower seed per plot ...................................................................... 35 2-5 Total bees observed and collected..................................................................... 36 3-1 Bee visitation of the tested wildflower species.................................................... 53 3-2 Bee tribe visitation by plant species.................................................................... 54 3-3 Pollen wash data ................................................................................................ 54 3-4 Pollen wash percentage likelihoods.................................................................... 54 3-5 Bumble bee pollen wash means......................................................................... 55 3-6 Bumble bee pollen wash percentage likelihoods................................................ 55 3-7 Halictus poeyi pollen wash means...................................................................... 55 3-8 Halictus poeyi pollen wash percentage likelihoods............................................. 55 4-1 Bee-plant associations from literature ................................................................ 89 7 LIST OF FIGURES Figure page 2-1 Map of University of Florida Plant Science Research and Extension Unit near Citra, Florida....................................................................................................... 37 2-2 Plot spacing at the wildflower sites. .................................................................... 38 2-3 Layout of plots .................................................................................................... 39 2-4