FlyTracks and SmellPrints: A Multiscale Forensic Blueprint Linking Necrophagous Insect Behavior, Environmental Decay,...

Forensic entomology has long been employed to estimate the post-mortem interval (PMI) by studying the ecological succession of necrophagous insects on decomposing remains. However, the mechanisms underlying species-specific attraction to decaying tissues, particularly in the early stages of decomposition, remain poorly understood. This study presents the first integrative investigation that bridges ecological, developmental, and molecular frameworks to explain dipteran attraction to decomposing remains and their potential application in biomedical detection. Over a 12-day semifield trial, we systematically documented the colonization dynamics and developmental timelines of three forensic indicator speciesLucilia sericata, Calliphora vomitoria, and Phormia reginausing euthanized albino rats as standardized vertebrate models. Statistical analyses, including one-way ANOVA, PCA, CVA, CCA, and path analysis, revealed distinct interspecies differences in larval development, pupation rate, adult emergence, and longevity. L. sericata emerged as the primary colonizer with the fastest development and highest early stage abundance, while P. regina exhibited delayed emergence and extended longevity patterns. In a novel molecular dimension, we identified conserved odorant receptor (OR) proteins across the three species using TBLASTN alignment and structural modeling via AlphaFold2. Molecular docking simulations revealed that L. sericata's ORs showed the highest binding affinities to cadaverine and putrescinekey biogenic amines emitted during early decompositionsuggesting a biochemical basis for its rapid attraction. This is the first study to link behavioral ecology with protein-level chemosensory mechanisms and computational predictions. It opens promising translational avenues for using synthetic ORs in biomedical diagnostics, particularly for the early detection of necrotic and potentially cancerous tissues based on shared volatile organic compounds. This work thus redefines the forensic entomological framework and paves the way for biologically inspired biosensor technologies.