Insulin family peptide members have key roles in regulating growth, metabolism, development, reproduction and longevity in vertebrates. Bombyxin, isolated from the silkmoth Bombyx mori, was the first Insulin-like peptide (ILP) identified in insects. Bombyxins have structural similarity to vertebrate insulin and amino acid sequence identity to mammalian ILP. To gain insight into the role of bombyxins, I have analyzed full genome of B. mori and identified five novel family bombyxin genes. Three of these genes have introns at almost same position as the human insulin gene. Temporal and spatial expressions of these genes have been observed to elucidate the molecular mechanisms of tissue development. Similar structure, location of intervening intron, and similar expression pattern between bombyxin and insulin genes have provide an important basis to elucidate evolutionary relationship and function of insulin family members in insects. This book promises to add considerable scientific value to the arena of molecular biology, evolutionary biology, genetics, insulin research and above all to the field of general science.