The main criterion of consolidation of this book, "The Cardinal Traits of Insect Morphology and Physiology", is to fulfil the need of the students, who are appearing for JRF, SRF, ARS, NET, Civils and several other competitive exams. To consolidate this book, it takes several days to collect, edit and update the vast literatures from various reference books, journals and different websites. Due to compilation of all the topics into one book, there may be a chance of missing some of the things which will be most useful to the students, so we have tried to consolidate the two basic topics which are utmost important in the entomology, which will give a vast knowledge within a short period of time instead of reading several books and wasting the precious time. It is one of the most useful books to the aspirants, who are appearing for different competitive exams.