Arthropod Succession Dynamics on Pig Carcasses in Tropical Urban Environments in South West Nigeria: Developing a Forensic Entomology Reference Database

Forensic entomology provides critical evidence in criminal investigations by estimating post-mortem intervals through arthropod succession patterns, but its legal admissibility in Nigerian courts is constrained by the absence of locally validated succession databases. Existing databases from temperate and subtropical regions are not applicable to Nigeria's humid tropical conditions where decomposition rates and insect phenology differ substantially. This study characterizes the complete arthropod succession sequence on pig carcasses in tropical urban environments in South West Nigeria, across seasonal and microhabitat variables, to produce a validated forensic reference database. Replicated pig carcass experiments will be conducted across wet season, late dry season, and early dry season conditions at urban, peri-urban, and forested sites in Lagos, Ogun, and Oyo states. Daily arthropod collections will record species presence, abundance, and succession stage from fresh to skeletal remains. Accumulated degree hours will be calculated as thermal accumulation benchmarks for each colonization event. Statistical models will generate minimum post-mortem interval estimates from succession stage input variables. The database and models will be validated using blind carcass experiments with known exposure periods. This study makes an original methodological contribution to tropical forensic entomology and provides Nigerian law enforcement agencies with legally defensible, peer-reviewed succession data for evidentiary use. Keywords: forensic entomology, arthropod succession, post-mortem interval, pig carcass, South West Nigeria