Insect Decline in the Anthropocene: Historical Parallels and Emerging Monitoring Tools

Insects, the most diverse group of animals on Earth, have historically evolved under strong environmental selective pressures, particularly fluctuations in atmospheric oxygen and temperature. During the Anthropocene, rapid climate change, pollution, and habitat alteration now impose new and compounded stresses, accelerating insect decline at unprecedented rates. Here, we present a conceptual framework comparing ancient environmental drivers of insect physiology, size, and diversity with modern anthropogenic stressors. This perspective reveals how contemporary pressures such as pesticide-induced hypoxia, climate-driven size alterations, and habitat fragmentation resemble and intensify ancient evolutionary constraints. We further highlight the disruption of key ecological services and the emergence of novel biotic pressures, including intensified competition and predation. Recent advances in trait-based modeling, environmental DNA analysis, remote sensing, and AI-powered monitoring offer promising avenues for assessing these complex interactions. Integrating these modern tools with historical evolutionary insights is essential for improving risk assessments, informing conservation strategies, and mitigating the cascading effects of insect diversity loss on ecosystems.