Caterpillars in the Middle: Tritrophic Interactions in a Changing World

Foreword
Acknowledgments
Contents
List of Contributors
Part I: Introduction
Introduction – Caterpillars as Focal Study Organisms
References
On Being a Caterpillar: Structure, Function, Ecology, and Behavior
Introduction
Basic Anatomy
Ontogeny, Life Cycles, and Diapause
Larval Diets
Population Dynamics in Brief
Caterpillar Enemies: Predators and Parasitoids
Morphological, Physiological, and Behavioral Adaptations for Circumventing Bottom-Up and Top-Down Pressures
Silk
Concluding Remarks
References
Part II: Impacts of the First Trophic Level on Caterpillar Ecology and Evolution
Surface Warfare: Plant Structural Defenses Challenge Caterpillar Feeding
Introduction
Plant Waxes
Chemical Characteristics of Waxes
Caterpillar Adaptations
Trichomes
Caterpillar Adaptations
Conclusions
References
Impacts of Plant Defenses on Host Choice by Lepidoptera in Neotropical Rainforests
Introduction
Herbivores in Neotropical Forests Prefer Young Expanding Leaves
Host Plant Selection by Herbivores and Plant Defensive Traits
Chemical Defenses
Chemical Defenses Affect Host Choice of Lepidoptera
Chemical Diversity Affects Diversity and Abundance of Lepidoptera
Trichomes
Extrafloral Nectaries and Ant Attraction
Chlorophyll Content and Rate of Leaf Expansion
Synchrony and Timing of Young Leaf Production: Phenological Defenses
Constraints on Host Specialization
Plant Traits Influence Herbivore Interactions with the Third Trophic Level
Global Climate Change Will Affect Insect Herbivores Through Changes Experienced by Their Host Plants
Conclusions
References
Ecology and Evolution of Secondary Compound Detoxification Systems in Caterpillars
Introduction
Proximate Mechanisms of Detoxification
Behavioral
Olfactory Receptors
Ionotropic Receptors
Gustatory Receptors
Transient Receptor Potential Channels
Non-receptor Chemosensory Gene Families
Prevention of Defense Response Induction
Diversion Strategies for Precursor Toxins
Physical Barriers (Peritrophic Membrane)
Target Site Insensitivity
Detoxification
Phase I: Oxidation, Hydrolysis, Reduction
Phase II: Conjugation
Phase III: Excretion
Microbial Interactions
Ultimate Causes of the Evolution and Maintenance of Detoxification Mechanisms
Bottom-Up Agents of Selection
Top-Down Agents of Selection
References
Sequestered Caterpillar Chemical Defenses: From “Disgusting Morsels” to Model Systems
Introduction
Historic Studies of Caterpillar Palatability/Unpalatability
Caterpillar Sequestration and Unpalatability
Iridoid Glycosides as a Model System
Caterpillar Sequestration: Comparisons Across Species
Caterpillar Sequestration and Unpalatability: Importance of Host Plant Variation
Caterpillar Sequestration and Chemical Defense: Consequences of Anthropogenic Change to the Environment
Introduced Plants
Other Types of Anthropogenic Change
Conclusions and Future Directions
References
Part III: Impacts of the Third Trophic Level on Caterpillar Ecology and Evolution
Acoustic Defence Strategies in Caterpillars
Introduction
Acoustic Antipredator Strategies in Insects
Acoustic Crypsis in Caterpillars
Sound and Vibration Reception in Caterpillars
Detecting Sounds and Vibrations Generated by Predators
Detection of Near-Field Sounds
Detection of Solid-Borne Vibrations
Detecting Sounds and Vibrations Made by Non-predators
Summary of Defensive Sound and Vibration Detection
Generating Sounds and Vibrations in Caterpillars
Sending Signals to Predators
Sending Signals to Non-predators
Summary of Caterpillar Defensive Sound Production
Conclusions and Future Research
References
Natural History and Ecology of Caterpillar Parasitoids
Introduction
Parasitoid Life History Diversity
Parasitoid Taxonomic Diversity
Hymenopteran Parasitoids of Caterpillars
Diversity: Superfamily Ichneumonoidea
Family Braconidae
Family Ichneumonidae
Hyperparasitism: More Layers in the Trophic Sandwich
Superfamily Chalcidoidea
Dipteran Parasitoids of Caterpillars
Stage Attacked
Mode of Attack
Immature Development
Ecology and Host Relations of Caterpillar Parasitoids
Community Patterns
Predictors of Susceptibility to Parasitoids
Parasitoid Host Ranges
Parasitoids in the Anthropocene
Habitat Loss and Fragmentation
Agricultural Intensification
Invasive Species
Climate Change
Consequences of Parasitoid Loss
References
Predators and Caterpillar Diet Breadth: Appraising the Enemy-Free Space Hypothesis
Introduction
Qualitative and Quantitative Review of the Evidence
Qualitative Evidence
Quantitative Evidence
Mechanisms of Enemy-Free Space Advantages to Specialists
Sequestration of Plant Allelochemicals
Specific Camouflage
Efficiency of Feeding Decisions
Manipulation of Host-Plant Volatiles
Appraisal and Refinement of the Hypothesis
Conclusions
Questions for Future Study
References
Caterpillar Responses to Ant Protectors of Plants
Introduction
The Study System: Cryptic Caterpillars on Ant-Tended Plants
Methods
Results
Discussion
Size Matters
All Ants Are Not Created Equal
Appearance May Not Matter to Ants, But What Does?
Sulphur Butterfly Caterpillars and Ants in a Changing World
Conclusion
References
The Natural History of Caterpillar-Ant Associations
Introduction
Terminology and Overview
Synopsis of Caterpillar-Ant Associations
Tineidae and Psychidae
Tortricidae
Cyclotornidae
Coleophoridae and Oecophoridae
Pyralidae
Crambidae
Erebidae
Notodontidae
Papilionoidea (Hesperiidae, Nymphalidae, Pieridae)
Ant Association in the Lycaenidae and Riodinidae
Adaptations of Adults
Adaptations of Caterpillars and Pupae
Vibratory Signaling
Lycaenidae
Curetinae
The Theclinae-Polyommatinae Assemblage
Lycaeninae
Miletinae
Aphnaeinae
Poritiinae
Riodinidae
Eurybiini
Nymphidiini
Mutualism and Manipulation: Caterpillar-Ant Trophobiosis in Lycaenidae and Riodinidae
Abiotic Effects, Obligate Associations, and Biogeography
References
Part IV: Multiple Interactive Effects Among All Three Trophic Levels
Caterpillars, Plant Chemistry, and Parasitoids in Natural vs. Agroecosystems
Introduction
Domestication and Plant Breeding Effects on Plant Secondary Metabolites
Plant Breeding, Plant Toxins, and Caterpillars
Plant Volatile-Mediated Interactions with Caterpillars and Parasitoids
Plant Toxin-Mediated Interactions with Caterpillars and Parasitoids
Climate Change, Plant Secondary Metabolites, and Phenological Match/Mismatch Between Trophic Levels
Conclusions/Future Directions
References
Host Plants as Mediators of Caterpillar-Natural Enemy Interactions
Introduction
Chemical Defenses
Physical Defenses
Plant Architecture
Resources
Future Directions
References
Host Plant Effects on the Caterpillar Immune Response
Introduction
Insect Immunity
Effects of Nutritional Content
Nutritional Content and the Caterpillar Immune Response
Nutritional Content and Caterpillar-Natural Enemy Interactions
Effects of Plant Secondary Chemistry
Plant Secondary Chemistry and the Caterpillar Immune Response
Plant Secondary Chemistry and Caterpillar-Natural Enemy Interactions
Knowledge Gaps and Avenues of Future Research
Linking Immunity to Fitness via Enemy Attack
Microbiome and the Immune Response
Specialist and Generalist Immunity
Conclusion
References
Trophic Interactions of Caterpillars in the Seasonal Environment of the Brazilian Cerrado and Their Importance in the Face of Climate Change
Introduction
Ecology of the Cerrado
Methods
The Seasonality of Caterpillar-Plant Interactions in the Cerrado
The Seasonality of Parasitoid-Caterpillar Interactions in the Cerrado
The Effects of Climate Change on Caterpillar Interactions in the Cerrado
References
The Impact of Construct Building by Caterpillars on Arthropod Colonists in a World of Climate Change
Introduction
Data Sources: Natural History and Experiments
Natural History and Correlations
Experiments
Experimental Evidence
Colonists of Leaf Constructs on Missouri Quercus
Interactions with a Colonist: The Asiatic Oak Weevil
Predictions: Effect of Construct Traits
Climate Change
Conclusions and Future Directions
References
Part V: Caterpillar Foodwebs in a World of Rapidly Changing Climate
Caterpillar Patterns in Space and Time: Insights From and Contrasts Between Two Citizen Science Datasets
Introduction
Datasets
iNaturalist
Caterpillars Count!
Family Composition
Geographic Patterns
Phenology
Climate Change and Phenological Mismatch
Conclusions
Literature Cited
Impacts of Climatic Variability and Hurricanes on Caterpillar Diet Breadth and Plant-Herbivore Interaction Networks
Introduction
Climatic Variability
Diet Breadth of Caterpillars and Its Influence on Plant-Herbivore Networks
Methods
Study Site
Hurricanes
Sampling Protocol
Caterpillar Diet Breadth
Plant-Herbivore Interaction Networks
Statistical Analyses
Results
Climatic Variability
The Most Abundant Caterpillar Species at Chamela Tropical Dry Forest and Their Diet Breadth
Plant-Caterpillar Interaction Networks
Discussion
Influence of Temperature
Influence of Precipitation
Influence of Hurricanes
Concluding Remarks
References
Plant-Caterpillar-Parasitoid Natural History Studies Over Decades and Across Large Geographic Gradients Provide Insight Into Specialization, Interaction Diversity, and Global Change
Introduction
Diversity and Networks of Species Interactions
Focus of This Chapter
The Plant-Caterpillar-Parasitoid Network Approach
Collection of Immature Lepidoptera
Rearing
Curation and Taxonomic Identification
Climate Data
Data Management and Dissemination
Quantifying Diversity of Interactions
Addressing Basic Questions in Ecology and Evolution
Caterpillar Defenses and the Evolution of Specialization
Interaction Diversity Across Environmental Gradients
Global Change and Trophic Interaction Networks
Climate Change and Parasitism
Global Change, Caterpillar Declines, and Network Erosion
Conclusion
References
Part VI: Synthesis
Synopsis and the Future of Caterpillar Research
Caterpillar Biology and Ecology in a Tritrophic World
Beginnings Along the Amazon
Advances in Technology
Forces Driving Coevolution
Defenses Against Natural Enemies
Development of Caterpillars in a Tritrophic World
Caterpillars in a Changing World
References
Subject Index
Taxonomic Index