Variable plants and herbivores in natural and managed systems

Contributors

Preface

Introduction. Variability: A Key to Understanding Plant-Herbivore Interactions

Text

References

Part I. Sources of Intraplant Variation and Consequences for Herbivores


1. Host Manipulation of Parasites: Within-Plant Variation as a Defense against Rapidly Evolving Pests

I. Introduction

II. Variation as a Plant Defense

III. Host Selection by Pemphigus Gall Aphids

IV. Between-Plant Variation in Resistance

V Within-Plant Variation in Resistance

VI. Impact of Within-Plant Variation on Parasites

VII. Discussion

VIII. Summary

References


2. Insect-Induced Chemical Signals Regulating Natural Plant Protection Responses

I. Introduction

II. Proteinase Inhibitors and Natural Plant Protection

III. Summary

References


3. Habitat Selection and Foraging Tactics of Caterpillars in Heterogeneous Trees

I. Introduction

II. Patterns of Feeding-Site Variation in Tree Canopies

III. The Impact of Variability on Defoliating Insects

IV Conclusions

References


4. Leaf Age as a Predictor of Herbivore Distribution and Abundance

I. Introduction

II. Temporal Variation in Leaf Quality

III. Temporal and Spatial Patterns of Herbivory

IV A Case Study of Within-Plant Variation and Its Effects on Herbivore Distribution

V Concluding Remarks

References


5. Competition between Herbivores and Increased Resource Heterogeneity

I. Introduction

II. Introduced Species: A Unique Encounter between Plant and Herbivore

III. Nutritional Requirements of Herbivorous Insects

IV Foliar Nitrogen: A Basis for Fitness in Elongate Hemlock Scale

V Quality and Availability of Food for Exotic Hemlock Scales

VI. Summary and Conclusions

References


6. Herbivore Population Dynamics and Plant Chemistry

I. Introduction

II. Effects of Stressful Environments on the Proximate Nutritional Quality of Plants

III. Theory of Plant Defense

IV Effect of Physical Stress on Plant Defenses

V. Defensive Responses of Plants to Herbivore Attack

VI. Offensive Adaptations of Herbivores for Discrimination between Suitable and Unsuitable Food and for Synchronizing Reproduction with the Availability of Suitable Food

VII. Offensive Adaptations of Herbivores that Stress, Increase the Nutritional Quality of, or Circumvent Induced Defensive Responses of Plants

VIII. Direct and Indirect Effects of Food-Plant Nutritional Quality and Defensive Posture on Fitness of Herbivores

IX. Changes in Herbivore Properties during Population Fluctuations

X. Possible Pheromonal Interactions among Plants and Herbivores

XI. Theory of Herbivore Outbreaks

XII. Conclusion

XIII. Summary

References

Part II. Sources of Interplant Variation and Consequences for Herbivores


7. Ecology of Host-Selection Behavior in Phytophagous Insects

I. Introduction

II. Habitat Selection

III. Discrimination between Host Species

IV. Conspecific Host Discrimination

V Conclusions

References


8. Influence of Vegetation Texture on Herbivore Populations: Resource Concentration and Herbivore Movement

I. Introduction

II. Testing the Resource-Concentration Hypothesis

III. Mechanisms that Underlie the Responses of Herbivores to Vegetation Texture

IV Questions of Scale and Some Issues in Experimental Design

V A Plea for a Theory of Herbivore Search

VI. Final Remarks

References


9. Tracking Variable Host Plants in Space and Time

I. Introduction

II. Natural History, Distribution, and Abundance of Prokelisia marginota

III. Wing Dimorphism in Prokelisia marginata, Mechanisms of Its Determination, and Correlates with Reproduction

IV Potential Competitors, Predators, and Parasites of Prokelisia marginata

V Distribution, Structure, and Growth Dynamics of Spartina alterniflora

VI. Food Items, Patches, and Habitats as Levels of Resource Organization

VII. Microhabitat Distribution of Planthoppers on Grass Rosettes and the Definition of Favorable Food Items

VIII. Within-Habitat Variation in the Favorableness of Spartina alterniflora: Differences in Patch Selection between Wing Forms

IX. Between-Habitat Variation in the Favorableness of Spartina alterniflora: Differences in Habitat Selection between Wing Forms

X. Geographic Differences in the Wing-Form Composition of Prokelisia marginata Populations

XI. Conclusions and General Considerations

References


10. Effects of Host-Plant Variability on the Fitness of Sedentary Herbivorous Insects

I. Introduction

II. Measuring the Effect of Adaptations on Fitness

III. Examples

IV Discussion

References

Part III. Host Plants and Genetic Variation in Herbivore Populations


11. Evolution of Feeding Specialization, Physiological Efficiency, and Host Races in Selected Papilionidae and Saturniidae

I. Introduction: The Feeding-Specialization Hypothesis

II. Conclusion

References


12. Adaptation, Host Specificity, and Gene Flow in the Black Pineleaf Scale

I. Introduction

II. Density Dependence

III. How Does Colonizing Ability Vary with Density?

IV Survivorship Patterns Affect the Scale Sex Ratio

V A Genetic Model of Adaptation and Specificity

VI. Discussion: Some Implications of Genetic Variation

References


13. An Evolutionary-Genetic View of Host-Plant Utilization by Insects

I. Introduction

II. Maintenance of Genetic Variation by Environmental Heterogeneity: Theory

III. Evidence

IV. Summary and Concluding Remarks

References

Part IV Host Variability and the Structure of Plant-Herbivore Communities


14. Individual, Population, and Geographic Patterns in Plant Defense

I. Introduction

II. Effects of Defoliation on Plant Fitness

III. Value of Leaf Tissue to the Plant

IV. Seasonal Change in Allocation to Growth, Defense, and Reproduction

V Patterns of Allocation in Plant Morphs, Cultivars, and Species

VI. Differences in Leaf Defense between Plant Populations

VII. Latitudinal, Altitudinal, and Island-Mainland Patterns in Plant Defense

VIII. Summary and Conclusion

References


15. Phytochemical Variation, Colonization, and Insect Communities: The Case of Bracken Fern (Pteridium aquilinum)

I. Introduction

II. Chemical Variation: Sources, Scales, and Impacts

III. Bracken Defense and the Insect Community: An Overview

IV Summary and Conclusion

References


16. Hypotheses on Organization and Evolution in Herbivorous Insect Communities

I. Introduction

II. The Evolution of Specialists

III. Hypotheses on Community Organization

IV Communities at Equilibrium or Nonequilibrium?

V The Role of Competition

VI. Vacant Niches in Ecological and Evolutionary Time

VII. Compound Communities

References

Part V Host Variability and Herbivore Pest Management


17. Genetics of Plant-Herbivore Systems: Interactions between Applied and Basic Study

I. Introduction

II. Current Procedures and Concepts in the Development and Deployment of Resistant Varieties

III. Theoretical Considerations

IV Available Data on the Genetics of Plant-Herbivore Interactions

V The Need for Future Interaction between Resistance Breeders and Evolutionary Biologists

References


18. Manipulation of Host Suitability for Herbivore Pest Management

I. Introduction

II. Manipulation of the Suitability of Individual Host Plants

III. Manipulation of the Spatial Variation in Host Suitability

IV Effects of Host-Plant Variation on the Parasitoids of Phytophagous Insects

V Conclusions and Directions for Further Research

References

Index