COMPARATIVE ECOLOGY AND MIMETIC RELATIONSHIPS OF ITHOMIINE BUTTERFLIES IN EASTERN ECUADOR By BOYCE ALEXANDER DRUMMOND III A DISSERTATION PRESENTED TO THE GRADUATE COUNCIL OF THE UNIVERSITY OF FLORIDA IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF FLORIDA 1976 UNIVERSITY OF FLORIDA 3 1262 08666 406 6 For Nancy, as she lays aside her net awhile to take up the caduceus ACKNOWLEDGMENTS It is my pleasure to thank the members of my committee, Drs. Thomas C. Emmel, Archie Carr, Clifford Johnson, and Thomas Walker, for the guidance and encouragement they have provided throughout my graduate career. I have profited greatly from their respective graduate courses and from the exposure to their divergent, but complementary, approaches to biology. I also thank Drs. John Ewel, Dana Griffin, and Jon Reiskind for helpful discussions and much useful information during the writing of this dissertation. For the countless ways in which they have assisted in all phases of the research reported here, I profess my deepest appreciation to Dr. Thomas Emmel, chairman of my committee, and Nancy Drummond, my wife and field assistant. Without the benefit of their help, many of the goals of this project could not have been accomplished. To Dr. Emmel, who first introduced me to tropical ecology and kindled my interest in the biology of the Lepidoptera, I am indebted for the constant personal, academic, and financial support he so graciously proffered. My wife, Nancy, whose great enthusiasm for our year of field work in Ecuador was matched only by her unflagging patience during the tedious year and a half that followed in Gainesville, assisted in the collection of specimens and population samples, handled most of the life-history rearings, and aided in the preparation and analysis of the data. For all this and much more I am thankfully beholden. 111 I am grateful to Dr. William G. D'Arcy, Missouri Botanical Garden, St. Louis, for identifying the solanaceous plants. At the Allyn Museum of Entomology, Sarasota, Florida, Dr. Lee Miller aided in the identification of several butterfly species and Jacqueline Miller kindly identified the Castniidae. I am indebted to Dr. Lincoln Brower, Amherst College, for loaning me a copy of Christine Papageorgis' dissertation, and to F. Martin Brown, Colorado Springs, Colorado, for loaning me one of the few extant copies of d' Almeida's "Melanges Lepidopteriques." I thank my wife, Nancy,' fbr translating the latter work and other papers from the French. Nancy Drummond also patiently typed and edited early drafts of the manuscript as well as most of the final copy, for which I am extremely grateful. Donna Gillis typed Tables 4 and 5 and the bibliography. The photography staff of the Office of Instructional Resources, University of Florida, prepared Figures 10 through 15. Nancy Drummond kindly drew Figures 33-35 and 46-47 and aided in the preparation of several others. The year of Ecuadorian field work was made possible only by the aid of a number of helpful persons and organizations in the United States and Ecuador. Dan Doyle of the Miami office of the Summer Institute of Linguistics severed yards of red tape at the Ecuadorian embassy to expedite the issuance of the required visas. Giovanna Holbrook of Holbrook Travel and the staff of JAARS (Jungle Aviation and Radio Service of SIL) kindly arranged the various transfers of our over- weight equipment and baggage to, from, and within Ecuador against improbable odds. Ruth and Steve Smith kindly stored our worldly possessions during our fourteen months in Ecuador. The personnel of IV the Ecuadorian Branch of the Summer Institute of Linguistics, especially John Lindskoog, Jonathon Johnson, and Don and Helen Johnson, facilitated our transportation in Ecuador and made available housing and supplies at Limoncocha. I am particularly grateful to Wayne and JoAnne Fitch, Jim and Kathie Yost, and Pat Kelley for many personal favors during the course of this research. Special thanks are due Mark and Phyllis Newell for allowing us to live in their spacious house at Limoncocha during the final three months of our stay. I thank Drs. Howard Weems and Robert Woodruff, Department of Entomology, Division of Plant Industry, Florida Department of Agriculture, for providing equipment and supplies. This research was supported in part by a Grant-in-Aid from Sigma Xi. TABLE OF CONTENTS 4 Page ACKNOWLEDGMENTS iii LIST OF TABLES . ix LIST OF FIGURES xi ABSTRACT xv CHAPTER I INTRODUCTION 1 Study Area 3 Historical Background 4 Climatic Description 8 Physical Description 20 The Butterfly Community at Limoncocha, Ecuador .... 30 Composition 30 Microhabitat Distribution 42 The Butterfly Subfamily Ithomiinae 45 The Plant Family Solanaceae 59 II METHODS 71 4. Ill ADULT ECOLOGY OF THE ITHOMIINAE 77 Microhabitat Requirements 77 Activity Patterns 81 Perching Behavior 82 Predation and Parasitism 84 Food Resources and Feeding Behavior 87 Locating Food Sources 89 Flower Feeding 90 Coevolution of Ithomiines and White-flowered Plants 110 Ithomiine Attractants "•* vi CHAPTER Page Population Ecology 117 Spatial Heterogeneity 117 The Capture-Mark-Recapture Program at Site 4 121 * IV REPRODUCTIVE BIOLOGY OF THE ITHOMIINAE 148 Courtship 148 Function of Hairpencils in Male Ithomiines .... 150 Mate-locating Behavior of Male Butterflies .... 154 Mate- locating Behavior of Ithomiine Males .... 1*55 Species-specific Male Courtship Behaviors .... 164 Pursuit Behavior of Courting Males 181 Function of the Display Perch 185 Mating 186 Sperm Precedence 189 Multiple Matings 191 Carrying Pair Behavior 193 Oviposit ion 195 Oviposition Strategies 200 Modes of Oviposition Behavior 215 Foodplant Specificity 223 V COMPARATIVE LIFE HISTORIES OF THE ITHOMIINAE 225 Immature Stages 226 Eggs 230 Larvae 231 Pupae 235 Generation Time £ 237 Parasitism and Predation 256 Parasitism 258 Predation 262 VI THE ITHOMIINAE-SOLANACEAE INTERFACE 267 Plant Defenses and Larval Adaptations 268 Larval Foodplant Relationships of the Ithomiinae ... 270 Patterns of Foodplant Utilization 281 Foodplant Specificity of Limoncocha Ithomiines . 286 Utilization of Larval Foodplants at Limoncocha .... 292 VII THE MIMETIC RELATIONSHIPS OF THE ITHOMIINAE 301 The Mimetic Subcomplexes at Limoncocha 302 Transparent Mimetic Complex 303 Tiger Mimetic Complex 315 vii Page CHAPTER ... 326 Polymorphic Mimetic Species ...••• Limoncocha Ithomiine Participation in ^ ^ Mimicry Complexes the Ithomiinae . • • 331 Evidence for Unpalatability in . 331 Circumstantial Evidence ^ Direct Evidence of Ithomiine Ecology .... 335 Some Mimetic Consequences 344 * ... VIII CONCLUSIONS ' ' 349 REFERENCES ... 361 BIOGRAPHICAL SKETCH vm LIST OF TABLES TABLE Page 1. Water Balance Calculation for Llmoncocha, Ecuador . 19 2. Comparison of the Butterfly Faunas of a Variety of Neotropical Locations 40 3. The Number of Genera and Species in the Eight Tribes of Ithomiinae 49 4. Species of Ithomiinae Collected at 'Llmoncocha, Ecuador ... 53 5. Species of Solanaceae Collected at Limoncocha, Ecuador ... 67 6. Nectar Sources of Ithomiine Butterflies 92 7. Summary of Collections of Ithomiine Butterflies Visiting Eupatorium I Flowers at Study Sites 1 and 3 in January 1974 108 8. Species Diversity of the Ithomiine Community at Study Site 4 132 9. Similarity of Species Composition Between Consecutive Samples of the Ithomiine Community at Study Site 4 (SjEfrenson's Quotient of Similarity) 136 10. Estimates of Longevity of Ithomiine Butterflies Based on Recapture Data at Study Site 4 144 11. Sex Ratio, Probability of Interspecific Encounter (PIE), and Probability of Intraspecif ic-heterosexual Encounter in the Ithomiine Community at Study Site 4 157 12. Postures of Male Ithomiines During Display Perch Courtship 172 13. Postures of Male Ithomiines During Patrol Perch Courtship 178 14. Mating Pairs of Ithomiines Observed at Limoncocha 188 15. Summary of Oviposition Parameters for Ithomiine Butterflies 202 16. Summary of Developmental Times of Ithomiine Butterflies 238 ix TABLE 17. Parasitism of Field-collected Ithomiine Eggs and Larvae 18. Larval Foodplant Records for the Ithomiidae 19. Numbers of Solanaceous Plants and Ithomiine Immatures at Site 4 20. Numbers of Solanaceous Plants and Ithomiine Immatures at Site 5 21. Numbers of Solanaceous Plants and Ithomiine Immatures at Site 1 22. Numbers of Solanaceous Plants and Ithomiine Immatures at Site 6 23. Summary of Foodplant and Juvenile Ithomiine Densities 24. Ithomiine Participation in Limoncocha Mimicry Complexes LIST OF FIGURES FIGURE Page 1. Map of East Ecuador (the Oriente) c 2. Map of Limoncocha, Ecuador .-. -, 3. Mean Monthly Temperatures, Mean Monthly Maximum Temperatures, and Mean Monthly Minimum Temperatures at Limoncocha, Ecuador 10 4. Annual Rainfall at Limoncocha, Ecuador: 1961-1974 11 5. Mean Monthly Rainfall at Limoncocha, Ecuador 13 6. Rainfall at Limoncocha, Ecuador: January 1974 to December 1974 13 7. Percent Rainy Days per Month and Mean Maximum Consecutive Rainless Days per Month at Limoncocha, Ecuador 14 8. Percent Days per Month with Greater Than 50% Cloud Cover at 1300 hours at Limoncocha, Ecuador 15 9. Mean Monthly Percent Relative Humidity at 1300 hours at Limoncocha, Ecuador 16 10. Near Beginning of Nature Trail (stem portion) in Secondary Forest 25 11. Nature Trail (loop portion) in Primary Forest, near Study Site 4 (100 m by 2 m transect) 25 12. Logging Trail, Study Site 3 27 13. Males of Scada batesi Haensch Feeding at Eupatorium I Flowers at Study Site 3 27 14. Logging Trail, Study Site 4 29 15. Forest Interior at Study Site 4 29 16. Number of Species in each Butterfly Family at Limoncocha, Ecuador 36 xi FIGURE 17. Number of Species in each Butterfly Family in Eastern Pernambuco, Brazil 18. Number of Species in each Butterfly Family in Eastern Espirito Santo and Southern Bahia, Brazil 19. Number of Species in each Butterfly Family at Jaru, Rondonia, Brazil 20. Relative Abundances of Species of Ithomiinae at Limoncocha, Ecuador 21. Ithomiine Feeding Activity at Heliotropium I Blossoms: June 26, 1974 22. Ithomiine Feeding Activity at Heiiotropium I Blossoms: June 29, 1974 23. Ithomiine Feeding Activity at Maranta I Blossoms: July 12, 1974 24.