TY - JOUR T1 - Oxidative Balance Constrains Insect Stress Tolerance, Aging, and Reproductive Investment Through Shared Physiological Trade-Offs A1 - Laura Keller A1 - Thomas Lehmann A1 - Simon Brunner A1 - Christoph Meier A1 - David Thompson JF - Entomological Research Letters JO - Entomol Res Lett SN - 3108-639X Y1 - 2023 VL - 3 IS - 2 DO - 10.51847/PsV58cEPZY SP - 72 EP - 83 N2 - Oxidative physiology is frequently invoked to explain insect responses to environmental stress, aging, and reproductive investment, yet the underlying evidence does not support a single continuum in which reactive oxygen species invariably represent damage, greater antioxidant activity invariably represents protection, or reproduction necessarily reduces somatic maintenance. This article develops a proposed physiological model in which oxidative balance is treated as a dynamic analytical state emerging from reactive-species generation and signaling, antioxidant and stress-protective capacity, molecular susceptibility, damage and repair, environmental demand, and life-history allocation. Evidence from insects shows that reactive oxygen species can participate in defined signaling pathways while also accumulating during damaging physiological states; antioxidant-related defenses can improve stress tolerance, but their effects depend on pathway, tissue, genotype, and exposure; and thermal, xenobiotic, nutritional, social, and activity-related challenges generate responses that vary with stage, stress history, and ecological context. Aging likewise cannot be reduced to cumulative oxidation because redox-sensitive maintenance, intervention timing, genotype, sex, activity, and laboratory–field transfer modify observed relationships. Reproductive evidence is especially heterogeneous: oxidative costs occur in some systems, are absent for particular behaviors or markers in others, and can be reversed in eusocial insects. The proposed oxidative-balance model therefore interprets stress tolerance, aging, and reproductive investment as conditionally coupled outcomes rather than obligatory consequences of a fixed oxidative budget. UR - https://esvpub.com/article/oxidative-balance-constrains-insect-stress-tolerance-aging-and-reproductive-investment-through-sha-wp6ifrpbghsr107 ER -