Research progress on insect photosensitive system and diapause regulation

Insect diapause is a critical biological adaptation that enables insects to adjust to external environments, maintain population stability, and achieve invasiveness. Photoperiod is one of the key factors regulating insect diapause. Insects perceive photoperiodic signals through their photoreceptive systems and phototransduction signaling pathways, allowing them to anticipate adverse environmental conditions (e.g., low or high temperatures and drought) and to orchestrate the diapause program by integrating photoperiod with temperature and other cues, thereby initiating diapause. The photoreceptive system of insects consists of multiple organs, including compound eyes, ocelli, and the Hofbauer-Buchner (H-B) eyelet, along with light-sensitive molecules such as rhodopsin and cryptochrome. These photoreceptive structures and molecules work synergistically to mediate light signal input. Currently, research on insect diapause primarily focuses on the relationship between the endocrine system and diapause, whereas studies exploring the connections between photoreceptive system structures, genes, and diapause remain relatively limited. This paper highlights recent advances in understanding the insect photoreceptive system, phototransduction signaling pathways, and their regulatory mechanisms in diapause behavior, aiming to provide insights into how environmental factors influence diapause.