Insects causee tremendous dammages to agricultural crops due to their feeding habits and because they transmit many viruses. While studies on some organisms have advanced into the post-genomics era, research on most agriculturally important plants and herbivores is just beginning to enter the phase of discovery. The application of new technologies such as whole-genome sequencing,  analysis of transcriptome and proteome to major insect pest to agriculture has allowed great progress in understanding the life style, reproduction, evolution and nuisance to crops caused by insect pests such as aphids, planthoppers, and whiteflies.  We believe that time has come to summarize progress and to have a glance over the horizon. In this Book experts in the field present their recent discoveries and discuss novel means to increase the different kinds of resistances of plants to efficiently limit the effects of pest, to understand and disturb the hormonal regulation of embryogenesis, molting, metamorphosis and reproduction, to determine the function of insect genes in diverse processes such as metabolism, interaction with plants, virus transmission, development, and adaptation to a changing environment. The knowledge presented here is discussed with the aim of further improving control strategies of insect pests and enhance resistances of crop plants.