Pausing Insect Activity

Summary

For all known life forms, activity is punctuated by periods of rest. Sleep may be the most familiar, but many other distinct dormant states occur on longer timescales, from weeks to months on end. Such suspended animation has garnered many different names: hibernation and torpor (in mammals and birds), brumation (in reptiles), diapause and quiescence (in insects and nematodes), aestivation (summer dormancy in vertebrates and invertebrates), hypobiosis, cryptobiosis, and latent life (in microorganisms).This abundance of terms is a consequence of the historically siloed nature of dormancy research — the phenomenon has been noted and described independently in different organisms across centuries. The most well-known of these, however, is likely hibernation. Not only is it an endearing behavioral trait belonging to charismatic fauna like bears and groundhogs, but it is also relatively easy to observe in nature. Where a brumating lizard might not attract much notice, a disheveled bear stumbling out of a den certainly does. And even if it seems far-fetched, the mechanisms behind mammalian hibernation are of increasing scientific interest due to their potential in human life extension and space travel.While hibernation commands the most attention, a growing body of research suggests that all forms of dormancy reflect similar underlying physiological, metabolic, and gene regulatory mechanisms. Indeed, the dormancy observed in non-mammalian species is no less gripping and ecologically consequential than mammalian hibernation. In no other group of organisms does the sheer scale of programmed dormancy stand out as staggeringly as in insect diapause. Unlike most other kinds of dormancy, largely characterized by physiological and behavioral suppression, insect diapause is a state of programmed developmental arrest. It’s a pause button pressed on one of the stages of their life cycle — either as eggs, larvae, pupae, or adults, depending on the species. As such, diapause removes ...