Warming climate intensifies systemic neurobehavioral-metabolic disruption induced by polyethylene microplastics in...

The ubiquity of microplastics (MPs) in the environment contrasts with the scarcity of integrative evidence regarding their sublethal effects on terrestrial invertebrates, particularly under climate change scenarios. Here, we evaluated the multisystemic responses of Tenebrio molitor larvae exposed to polyethylene microplastics (PE-MPs) under two contrasting climate regimes (1000 ppm CO₂/27 °C and 1500 ppm CO₂/28.5 °C). The experimental design comprised three diets (control, 0.005 %, and 0.1 % PE-MPs) offered for 15 days, followed by integrative analyses encompassing particle bioaccumulation, behavioral assessment, and a comprehensive panel of biochemical biomarkers (energy reserves, oxidative stress, neurotransmitters, and digestion), integrated through both univariate and multivariate statistical approaches. Although no lethal effects or impairments in body mass gain were observed, PE-MP exposure triggered a multisystemic functional reorganization in T. molitor, characterized by the prioritization of rapidly mobilizable energetic fuels (lipids and carbohydrates) over protein maintenance, intensification of oxidative stress, and disruption of digestive homeostasis. These adjustments translated into neurochemical alterations-marked by shifts in dopaminergic/serotonergic balance and cholinergic inhibition-that collectively sustained patterns of locomotor hyperactivity under light stimulus. Multivariate integration revealed nonlinear signatures and cumulative shifts, with climate acting as a critical modulator, amplifying MP impacts and driving trajectories toward greater severity. Our findings demonstrate that PE-MPs impose a baseline multisystemic cost that integratively compromises distinct physiological and behavioral axes, a burden that is exacerbated under warming and elevated CO₂ conditions. These results underscore the need for MP risk assessments to incorporate future climate scenarios and integrative functional approaches capable of capturing systemic reconfigurations rather than isolated effects.