Table of Contents1. Plant Apparency and Chemical Defense.- 2. Insect Plant Interactions: Nutrition and Metabolism.- 3. Milkweed Cardenolides and Their Comparative Processing by Monarch Butterflies (Danaus plexippus L.).- 4. A General Theory of Plant Antiherbivore Chemistry.- 5. Biochemical Parallelisms of Repellants and Attractants in Higher Plants and Arthropods.- 6. Cotton Plant and Insect Constituents that Control Boll Weevil Behavior and Development.- 7. Chemical Messengers in Insects and Plants.- 8. Secondary Plant Substances as Materials for Chemical High Quality Breeding in Higher Plants.