University of Tehran Iranian Journal of Plant Protection Science 2008-4781 56 1 2025 06 01 Diapause and its regulation by endocrine signaling in insects: from environmental stimuli to management implications in plant protection Diapause and its regulation by endocrine signaling in insects: from environmental stimuli to management implications in plant protection 1 23 105904 10.22059/ijpps.2026.409902.1007105 FA Azam Amiri Department of Landscape Engineering, College of Geography and Environmental Planning, University of Sistan and Baluchestan, Zahedan, Iran Ali R. Bandani Plant Protection Department, College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran Journal Article 2025 04 09 Diapause is a major seasonal life-history strategy in insects that enables populations to survive predictable unfavorable periods (e.g., winter cold, summer drought, or host scarcity) through a hormonally regulated, preprogrammed arrest of development and/or suppression of reproduction. This is not a “simple pause”; rather, it is a phase-structured process encompassing induction, preparation, initiation, maintenance, termination, and, in many cases, post-diapause quiescence. The mechanism is accompanied by profound metabolic reorganization, energetic budgeting, and enhanced stress tolerance. The decision to enter, maintain, or terminate diapause is driven primarily by reliable environmental cues—especially photoperiod and subsequently temperature—while nutritional and moisture-related factors can further modulate this response in some systems. These inputs are translated into persistent physiological states through neuroendocrine networks and key endocrine axes involving juvenile hormone, ecdysteroids, and insulin/insulin-like signaling, thereby redirecting resource allocation from growth and reproduction toward storage, maintenance, and survival. This review also emphasizes the importance of distinguishing diapause from quiescence and avoiding the frequent confusion between them, because misclassification directly affects data interpretation and the prediction of emergence timing. From a plant-protection and integrated pest management (IPM) perspective, diapause governs the timing of damaging life stages and the width of control-sensitive windows; therefore, diapause-informed phenology models, coupled with field monitoring, can improve forecasting, sharpen intervention timing, and support more realistic management decisions under climate change. Diapause is a major seasonal life-history strategy in insects that enables populations to survive predictable unfavorable periods (e.g., winter cold, summer drought, or host scarcity) through a hormonally regulated, preprogrammed arrest of development and/or suppression of reproduction. This is not a “simple pause”; rather, it is a phase-structured process encompassing induction, preparation, initiation, maintenance, termination, and, in many cases, post-diapause quiescence. The mechanism is accompanied by profound metabolic reorganization, energetic budgeting, and enhanced stress tolerance. The decision to enter, maintain, or terminate diapause is driven primarily by reliable environmental cues—especially photoperiod and subsequently temperature—while nutritional and moisture-related factors can further modulate this response in some systems. These inputs are translated into persistent physiological states through neuroendocrine networks and key endocrine axes involving juvenile hormone, ecdysteroids, and insulin/insulin-like signaling, thereby redirecting resource allocation from growth and reproduction toward storage, maintenance, and survival. This review also emphasizes the importance of distinguishing diapause from quiescence and avoiding the frequent confusion between them, because misclassification directly affects data interpretation and the prediction of emergence timing. From a plant-protection and integrated pest management (IPM) perspective, diapause governs the timing of damaging life stages and the width of control-sensitive windows; therefore, diapause-informed phenology models, coupled with field monitoring, can improve forecasting, sharpen intervention timing, and support more realistic management decisions under climate change. https://ijpps.ut.ac.ir/article_105904_171283f255a39dc179153b374054c60e.pdf