Energetic shifts reflect survival likelihood in Anopheles gambiae

Life history theory predicts that resource allocation adapts to ecological and evolutionary pressures. We investigated resource and energy in the malaria vector Anopheles gambiae following exposure to two stressors: blood meals and infection by the microsporidian Vavraia culicis. Our findings reveal the costs of blood feeding and parasitism on longevity, highlighting trade-offs in lifetime protein, carbohydrate, and lipid reserves. Notably, shifts in carbohydrate-to-lipid ratios were associated with survival likelihood, with survivors exhibiting higher resource reserves and uniquely transitioning from carbohydrate to lipid utilization, a pattern absent in non-survivors. This study emphasizes the coevolutionary dynamics between hosts and parasites, highlighting how intrinsic and extrinsic factors shape host physiology. More broadly, our results underscore the importance of integrating host metabolic responses into ecological and epidemiological frameworks to enhance understanding of parasite transmission and survival strategies. HighlightsO_LIHaving a blood meal did not affect mosquito longevity, resource content or V. culicis parasitemia. C_LIO_LIAlive mosquitoes harboured fewer spores than mosquitoes that had just died, independently of the stage of infection, supporting the parasite load upon death hypothesis. C_LIO_LIAlive mosquitoes exhibited a shift in their usage of the energetic reserves (i.e., carbohydrates to lipids) late in life, which mosquitoes at death did not. C_LIO_LIOur findings support the hypothesis that Plasmodium may have coevolved with its vectors dynamics of lipid release, a nutrient essential for its development. C_LI