Diapause is a strategy used by insects to withstand adverse environmental conditions that is critical to the survival, propagation and evolution of many species. Diapause has three stages; pre-diapause, diapause and post-diapause. Pre-diapause is comprised of an induction and preparation period and is important to successful diapause. We here summarize the environmental factors related to diapause induction, review the function of different endocrine hormones and circadian genes, as well as epigenetic modifications including DNA methylation, small RNA and histone modifications, in the regulation of diapause induction. We also summarize the molecular pathways of diapause induction with reference to the reproductive diapause of Drosophila melanogaster. Finally, we discuss unresolved questions in the study of insect diapause induction and prospects for the application of diapause research in pest control.