Prepupal diapause reduces adult lifespan in the solitary alfalfa leafcutter bee

Authors: SANTOS, PRISCILA - Utah State University; LLOYD, ADDISSON - Utah State University; STOKER, CARSEN - Utah State University; McCabe, Lindsie; Cox-Foster, Diana; KAPHEIM, KAREN - Utah State University

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2025
Publication Date: 10/23/2025
Citation: Santos, P.F., Lloyd, A., Stoker, C., Mccabe, L.M., Cox-Foster, D.L., Kapheim, K.M. 2025. Prepupal diapause reduces adult lifespan in the solitary alfalfa leafcutter bee. Scientific Reports. https://doi.org/10.1038/s41598-025-21239-4.
DOI: https://doi.org/10.1038/s41598-025-21239-4

Interpretive Summary: Diapause, a state of suspended development, allows many insects to survive harsh environmental conditions. While its impact on reproduction is well-documented, the long-term effects of diapause on adult lifespan and overall health remain largely unknown. This study investigated the consequences of diapause in Megachile rotundata, a bee species capable of entering a dormant state. Researchers compared bees that underwent diapause with those that did not. The findings revealed a trade-off: bees that experienced diapause had shorter lifespans. Although immune function appeared unaffected in newly emerged adults, those emerging from diapause exhibited higher levels of oxidative stress, a sign of cellular damage, and elevated levels of PTTH, a hormone crucial for insect development. These results demonstrate the physiological costs associated with diapause, providing valuable insights into how this survival strategy shapes the life history and longevity of insects.

Technical Abstract: Diapause is an adaptation that allows many insects to survive adverse environmental conditions. While diapause-associated trade-offs with reproduction are well-documented, its potential impact on lifespan and long-term adult physiology remains poorly understood. In this study, we used Megachile rotundata, a bivoltine solitary bee species with facultative diapause, to investigate the effects of prepupal diapause on adult lifespan and physiology. We compared individuals that underwent diapause to those did not. Our findings reveal a trade-off between prepupal diapause and adult lifespan, with diapause females exhibiting shorter lifespans. Newly-emerged females showed no differences in immune response capacity but females that emerged from diapause had higher levels of oxidative stress and slightly elevated PTTH expression. These results highlight the physiological consequences of alternative developmental pathways and provide new insights into how diapause strategies shape life-history traits in insects.