Forensic entomologists use insect evidence to reconstruct the circumstances of a crime scene at/around the time of event (e.g., estimation of time since death, determination of body movement). Forensically-important flies (FIF) are found in various stages of human decomposition. They lay eggs on a body and their maggots consume soft tissues, which significantly affect the pattern and rate of decomposition. Anthropology Research Facility (ARF, so-called the ‘Body Farm’) of the University of Tennessee has been used for human decomposition research for 40 years. Despite the important role of FIF in the process of human decomposition, it has not been fully investigated what species of FIF are present at the ARF. The purpose of this study is to investigate the seasonal and regional composition of FIF species at the ARF. This long-term study will serve as a basis to evaluate the effect of different FIF species on human decomposition.
Flies were collected from 27 traps across the ARF twice a month between March 2018 – April 2019 (No flies were caught between December 2018 – March 2019). As of November 2019, morphological identification has been completed on 75% of the sample (2,513 out of 3,357 flies).
Blowflies (Diptera: Calliphoridae) comprise approximately 94% of ID’ed flies. Out of 16 blowfly species identified, Phormia regina turned out to be most dominant in the Spring and Summer, but Lucilia coeruleiviridis was the most dominant species in the Fall. A significant change in the regional composition of FIF species by season was also noticed. Decomposition states of nearby bodies appeared to influence the regional distribution of the flies.
Deeper knowledge about the species composition and activities of FIF at the ARF will enhance understanding on human decomposition and, eventually, contribute to a more accurate estimation of time since death in a crime scene.