The Microbiome as a Protagonist of Xylophagous Insects in Adaptation to Environmental Conditions and Climate Change.

Xylophagous insects represent a diverse group of species whose life cycles are trophically associated with wood at various stages of decomposition. In forest ecosystems, they play a pivotal role in wood degradation and biogeochemical nutrient cycling. Their remarkable adaptation to feeding on structurally complex and nutrient-poor woody substrates has been largely mediated by long-term symbiotic interactions with gut microbiota. This review synthesizes current knowledge on the molecular and ecological mechanisms underlying insect-microbiota interactions, with particular attention paid to the impact of environmental stressors-including elevated temperature, shifts in moisture regimes, and pollution-on microbial community structure and host adaptive responses. We critically evaluate the strength of evidence linking climate-driven microbiome shifts to functional consequences for the host and the ecosystem. The ecological implications of microbiota restructuring, such as impaired wood decomposition, decreased disease resistance, facilitation of xylophagous species spread, and alterations in key biotic interactions within forest biocenoses, are discussed. Particular emphasis is placed on the integration of multi-omics technologies and functional assays for a deeper, mechanistic understanding of microbiota roles. We also assess the potential and limitations of microbiome-based approaches for insect population management, with the overall goal of maintaining and enhancing the resilience of forest ecosystems under ongoing climate change.