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Stress can influence lifespan in both positive and negative ways, depending on exposure intensity and duration. However, mechanisms driving positive stress effects on lifespan remain poorly understood. Prolonged hypoxia extends the lifespan of overwintering prepupal Megachile rotundata. Here, we explore telomere length and reduced oxidative stress as potential mechanisms of this extended lifespan. We hypothesized high antioxidant capacity under hypoxia reduces oxidative damage and telomere loss. We exposed prepupae to 10, 21 or 24% oxygen for up to 9 months and measured monthly survival, telomere length, antioxidant capacity, and lipid peroxidation across treatment duration for prepupae and adults. After 9 months of exposure, survival was highest in hypoxia and lowest in hyperoxia. Telomere length did not differ among oxygen treatments but increased in adults compared to prepupae. Total antioxidant capacity and lipid peroxidation showed no significant differences among oxygen treatments, suggesting compensatory responses to maintain baseline oxidative levels. 

Synopsis Throughout their lives, organisms must integrate and maintain stability across complex developmental, morphological, and physiological systems, all while responding to changing internal and external environments. Determining the mechanisms underlying organismal responses to environmental change and development is a major challenge for biology. This is particularly important in the face of the rapidly changing global climate, increasing human populations, and habitat destruction. In January 2024, we organized a symposium to highlight some current efforts to use modeling to understand organismal responses to short- and long-term changes in their internal and external environments. Our goal was to facilitate collaboration and communication between modelers and organismal biologists, which is one of the major aims of the Organismal Systems-type Modeling Research Coordination Network, OSyM. Accompanying this introduction are a series of papers that are aimed to enhance research and education in linking organismal biology and modeling and contribute to building a new community of scientists to tackle important questions using this approach. 

Abstract Megachile rotundata (F.) is an important pollinator of alfalfa in the United States. Enhancing landscapes with wildflowers is a primary strategy for conserving pollinators and may improve the sustainability of M. rotundata. Changing cold storage temperatures from a traditionally static thermal regime (STR) to a fluctuating thermal regime (FTR) improves overwintering success and extends M. rotundata’s shelf life and pollination window. Whether floral resources enhance overwintering survival and/or interact with a thermal regime are unknown. We tested the combined effects of enhancing alfalfa fields with wildflowers and thermal regime on survival and macronutrient stores under extended cold storage (i.e., beyond one season). Megachile rotundata adults were released in alfalfa plots with and without wildflower strips. Completed nests were harvested in September and stored in STR. After a year, cells were randomly assigned to remain in STR for 6 months or in FTR for a year of extended cold storage; emergence rates were observed monthly. Macronutrient levels of emerged females were assessed. FTR improved M. rotundata survival but there was no measurable effect of wildflower strips on overwintering success or nutrient stores. Timing of nest establishment emerged as a key factor: offspring produced late in the season had lower winter survival and dry body mass. Sugars and glycogen stores increased under FTR but not STR. Trehalose levels were similar across treatments. Total lipid stores depleted faster under FTR. While wildflowers did not improve M. rotundata survival, our findings provide mechanistic insight into benefits and potential costs of FTR for this important pollinator.