Chapter. 1. Patterns of insect evolution -- Chapter. 2. Overview of insect midgut function -- Chapter. 3. Types and chemistry of diets -- Chapter. 4. Ordinary digestive enzymes -- Chapter. 5. Midgut cells, microvillar membranes and secretory mechanisms -- Chapter. 6. Midgut pH buffering, nutrient absorption, fluid fluxes, and enzyme recycling -- Chapter. 7. Midgut extracellular layers and their function -- Chapter. 8. Endocrine regulation of insect digestion -- Chapter. 9. Recruitment of lysosomal cysteine and aspartic endopeptidases as digestive enzymes -- Chapter. 10. Plant, bacterial, and fungal cell wall degrading enzymes -- Chapter. 11. Mechanisms of avoiding the action of plant inhibitors on digestion -- Chapter. 12. Role of microorganisms in digestion and nutrition -- Chapter. 13. Molecular view of digestion and absorption in the major insect orders -- Chapter. 14. General trends in the evolution of digestive systems -- Chapter. 15. New technologies of insect control that act through the gut.