The Ecology and Evolution of Ant-Plant Interactions

Preface xi 1. Ant-Plant Interactions 1 The Origin and Early Evolution of Ant-Plant Associations Phylogenetic Associations A Brief History of the Associations Coevolution and Interspecific Interactions 2. Antagonistic Interactions: Leaf-Cutting and Seed-Harvesting Ants 21 Leaf-Cutting Ants (Grazing) Seed-Harvesting Ants (Predation) 3. Mutualism from Antagonism: Ants as Primary Seed-Dispersers 42 The Reward: Elaiosomes Seed Dispersal by Ants Myrmecochory: Distribution and Significance Worldwide Conclusion APPENDIX 3.1. Myrmecochory in Eastern North America, Japan, and Europe APPENDIX 3.2. Myrmecochory in Australia and South Africa APPENDIX 3.3. Myrmecochory in the Neotropics 4. Mutualism from Opportunism: Ants as Secondary Seed-Dispersers 68 The Reward: Fallen Fleshy Diaspores Diaspore Attributes and Patterns of Ant Attendance Ant Effects on Seeds and Seedlings Directed Dispersal of Seeds by Ponerine Ants Prospect 5. Mutualism from Antagonism: Ants and Flowers 85 Pollination by Ants Discouragement of Floral Visits by Ants APPENDIX 5.1. Plant Species in Which Ant Pollination Has Been Demonstrated 6. Antagonism and Mutualism: Direct Interactions 99 The Pseudomyrmex-Acacia Association Ants, Plants, and Food Bodies Ant-Inhabited Plants Offering No Direct Food Rewards Ants, Plants, and Extrafloral Nectaries Plant Defensive Strategies and Induced Responses The Nature of the Associations and the Importance of Conditionality Topics for Future Consideration APPENDIX 6.i. Flowering Plants That Maintain a Nonsymbiotic Relationship with Ants 7. Antagonism and Mutualism: Indirect Interactions 142 Ants, Plants, and Hemipterans Variable Outcomes in Ant-Hemipteran Systems The Effect of Ant-Hemiptera Interactions on Host Plants Ant-Hemiptera Associations and the Evolution of Extrafloral Nectaries 8. Nutrition of Plants by Ant Mutualists: Life History of Ant-Fed Plants and Ant-Garden Systems 163 Ant-Fed Plants Ant Gardens Conclusion APPENDIX 8.1. Ant-Fed Plants That Absorb Nutrients from Ant Debris 9. Canopy-Dwelling Ants, Plant and Insect Exudates, and Ant Mosaics 177 Canopy Ants: Main Features and Trophic Role The Competitive Environment Ant Mosaics Plant and Insect Exudates and Ant Community Structure The Effect of Trophobiont Tenders on Associated Herbivores and on the Host Plant 10. Variation in Ant-Plant Interactions 193 Temporal Variation Spatial Variation APPENDIX 10.1. Plants with Extrafloral Nectaries APPENDIX 10.2. Ant Species Using Plant-Derived Food Resources 11. Ant-Plant Interactions in Agriculture 215 Agricultural Systems, Herbivores, and Ants Ants as Biological Control Agents Case Studies Biological Control and Interspecific Interactions 12. Overview and Perspectives 231 Literature Cited 253 Index 313