Structure and functioning of reproductive organs are the prerequisites for the success of insects world wide, thus, the insect ovary has been a matter of scientific interest from the very beginning of modern biology. Fundamental topics of cell biology, genetics, morphology, endocrinology, and behaviour can be learnt by the study of this organ. This basic knowledge is now used by applied scientists who are elaborating new methods of "soft" pest control. This book deals with cytology, morphology, phylogeny, and, in part, genetics (meiosis, sex chromosomes and determination, pathenogenesis) and is aimed at pure and applied scientists of universities, pharmacological and chemical industries engaged in insect pest control, and students. This book should be of interest to postgraduates and researchers in entomology, especially reproduction; and to researchers of pest control.