Sex-Specific Effects of Protein Limitation and Mating on Longevity in Bactrocera oleae

Longevity in the olive fruit fly, Bactrocera oleae, is a plastic trait shaped by the synergistic interaction between reproductive effort, sex, and protein availability. This study investigated how the survival of 800 individuals is affected by protein limitation and mating status. Results from Cox proportional hazards analysis demonstrate that mating and protein deprivation significantly increase mortality risk. Under protein-deprived conditions, mating increased the mortality hazard by 146.5% for males and 121.5% for females compared to virgins. Notably, a significant Sex × Diet interaction (p = 0.022) confirmed that among virgin individuals, the relative mortality hazard increase under protein scarcity was nearly double for males (97.5%) compared to females (51.1%), indicating a higher statistical tolerance for nutritional stress in females. Furthermore, statistical validation confirmed that diet exhibited a significant time-dependent effect (p = 0.029), indicating that nutritional deficits act cumulatively over the fly’s lifespan. These findings suggest that B. oleae longevity is governed by dynamic, synergistic pressures, with females exhibiting a lower hazard of death under resource-limited conditions, an insight essential for refining demographic models in integrated pest management (IPM) strategies.