Variable plants and herbivores in natural and managed systems

Variable Plants and Herbivores in Natural and Managed Systems examines individual, population, species, and community responses of herbivores to plant variation, with emphasis on insects, fungi, bacteria, and viruses. It is divided into five parts encompassing 18 chapters that discuss variability as a mechanism of defense used by plants against their parasites and the effects of variability on herbivores at several different levels of complexity.
After a brief discussion on plant-herbivore interactions, the first part of this book considers sources of within-plant variation and effects on the distribution and abundance of herbivores. Part II examines interplant variation, the co-evolutionary problems it poses for herbivores, and the ecological and evolutionary responses of these animals. It discusses the effects of host-plant variability on the fitness of sedentary herbivorous insects. Part III discusses the role of host variability in the evolution of feeding specialization, genetic differentiation, and race formation. The importance of host variation to the organization of herbivore communities and the manipulation of host-plant variability for the management of herbivore pest populations are presented in the remaining parts.
This book will be helpful to agriculturists, silviculturists, biologists, and researchers who wish to expand their knowledge in dynamics of plant-herbivore relationships.

Contenu

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 …