This text book and practical manual is written keeping in mind a broad spectrum of readers. It will help graduate level students, lecturers of this subject, entomopathologist, microbiologists, and researchers supplementing information about basics of insect pathology. Because this book acts as a dossier of the available information, its utility as a textbook as well as practical manual for an insect pathology class is evident. Comprehensive literature citations extended for those, who wish to obtain further information. Authors have tried to cover all sub-disciplines of the subject, but shortcomings are unavoidable. Contents: Theory 1. Introduction 2. History of insect pathology 3. Infection of insects by various pathogen 4. Concept of Epizootiology 5. Defence mechanisms in insects against pathogens 6. Mass production techniques of pathogens 7. Safety and registration of microbial pesticides in India 8. Use of insect pathogens in IPM Practicals 1. Equipment used and safety measures to be observed in insect pathology laboratory 2. Identification and symptoms of infection – bacterial insect pathogens 3. Identification and symptoms of infection – fungal insect pathogens 4. Identification and symptoms of infection – viral insect pathogens 5. concept of pathogen load 6. Extraction, Isolation and Culturing of fungal pathogens from live or dead insect/organism 7. Extraction, Isolation and Culturing of bacterial pathogens from live or dead insect/organism 8. Extraction, Isolation and Culturing of viral pathogens from live or dead insect/organism 9. To know the different laboratory bioassay techniques for evaluation of different insecticides against insect pests 10. Bioassay of Fungal Entomopathogens against Grass hoppers or Locusts