Low-Temperature Stress Impairs Reproductive Performance and Olfactory Behaviors in Tuta absoluta via Metabolic and...

Low temperature critically pressures insect pest distributions and population dynamics; however, integrated understanding of cold stress responses in invasive pests, particularly at the adult stage, remains limited. Here, we investigated the integrated physiological, biochemical, metabolomic and transcriptomic responses of Tuta absoluta (Meyrick, 1917) exposed to control (CT: 25 °C), moderate cold stress (MCS: 15 °C) and severe cold stress (SCS: 5 °C) conditions. Our results revealed that low-temperature stress impaired T. absoluta emergence, survival, fecundity and egg hatching in a stress intensity-dependent manner. Also, low temperature reduced the olfactory-mediated host-seeking behaviors of T. absoluta females. The biochemical analyses revealed depletion of triglycerides, glycogen and Na⁺/K⁺-ATPase activity alongside compensatory trehalose accumulations, while antioxidant enzyme activities (SOD, POD, CAT) were differentially modulated indicating progressive oxidative defense impairment under low temperature. Untargeted metabolomic profiling identified extensive differential metabolite accumulations, revealing systematic dysregulation of alkaloid biosynthesis, amino acid metabolism and central carbon metabolic pathways. Transcriptomic analysis identified several differentially expressed genes (DEGs) enriched in thermogenesis, oxidative phosphorylation, MAPK signaling and neurodegeneration-associated pathways. Furthermore, integrative transcriptome-metabolome analysis revealed coordinated gene-metabolite regulatory networks scaling systematically with cold stress intensity. These findings advance our mechanistic understanding of thermal stress adaptations in T. absoluta and may contribute to the development of climate-informed pest management strategies.