Climate Change Impacts on Insect Biodiversity and Distribution: A Review

Insects are vital to various ecosystems as pollinators, decomposers, and food sources for many organisms. They dominate diverse terrestrial (e.g., glassland) and aquatic (lakes, oceans, rivers, etc.) ecosystems. Climate change is an increasing global issue with extensive impacts on ecosystems, mostly on insect diversity and distribution. Insects, because of their brief life span and ecological vulnerability, are used as early warning signs of environmental change. This review encapsulates the encountered and anticipated impacts of climate change temperature change, changed precipitation patterns, and loss of habitat on insects. Key impacts are changes in phenology, expansions or contractions of ranges, population dynamics, and heightened extinction risk. Elevated atmospheric carbon dioxide levels are increasingly recognised for their profound impact on terrestrial ecosystems, particularly in the dynamics between plants and insects. Under heightened CO₂ conditions, plants exhibit significant alterations in physiology and biochemistry, including changes to nutrient composition and the production of secondary metabolites. Such modifications can reduce the efficacy of innate plant defences, rendering them more susceptible to herbivorous attack. In parallel, insects may adjust their feeding behaviour and metabolic pathways in response to these changes, potentially exacerbating pest pressures on agricultural systems. Implications for ecosystem services like pollination and biological control are also addressed in the paper, as well as pointing out the importance of enhanced monitoring, modeling, and conservation efforts.