Current Status of Five Warm Season Diptera Species in Estimating the Post-Mortem Interval

Abstract

The accurate estimation of the time of death (Post-Mortem Interval, PMI) is of great importance when reconstructing the actual events at a crime scene following the recovery of a body. The reliability of the PMI is vital to validate witness statements and suspect alibis. The PMI estimation based on insects collected from remains relies on two fundamental principles. Firstly, the development of an insect is proportionate to its surrounding environmental condition, and secondly, colonization by insects and other arthropods typically occur according to predictable sequences subjected to seasonality, environment in which the decomposition takes place, and the possible presence of xenobiotics in the food substrate (e.g., drugs). Dipteran species of the family Calliphoridae are the most common species colonizing a corpse and carcass, and a large body of research in entomology is focused on their developmental data. Such data is used forensically to estimate the PMI via three types of calculation: accumulated degree day/hour, table of growth, and isomegalen/isomorphen diagram. Much of this research has been documented during the 20th century, in different countries, using different experimental designs and analyses. This review tabulates development data obtained from 74 manuscripts published between 1933 and 2021 for five cosmopolitan blowfly species associated with the early stages of decomposition during the warmer seasons: Chrysomya megacephala, Ch. rufifacies, Ch. albiceps, Lucilia sericata, and L. cuprina. This review highlights the importance of establishing a standardized protocol to conduct future development studies and maintaining a system for retrieval of this data for future PMI calculations.

Effects of larval diets on some biological parameters and morphometric and biochemical analysis of ovaries of Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)

“…In contrast, we found that L. cuprina required two more days to complete larval development on beef liver than on chicken or beef meat. Bambaradeniya et al (2023) observed somewhat slower development of L. cuprina on pig liver than on pig or beef muscle tissue and suggested that this was due to biochemical and structural differences in the tissue types. It is also worth noting that the species as well as type of host tissue can affect development times.…”

“…flies are among the most important blow flies used in forensic entomology due to their frequent occurrence on human cadavers (Smith 1986). Because larvae of the Australian sheep blow fly, L. cuprina (Wiedemann), are among the first insects to arrive at a corpse, their presence and age is used to estimate the postmortem interval (PMI) (Bambaradeniya et al 2023). Moreover, larvae of L. cuprina are commonly used as maggot therapy to treat wounds (Paul et al 2009, Tantawi et al 2010).…”

A Summary of Concepts, Procedures and Techniques Used by Forensic Entomologists and Proxies

“…However, after this period, fly eggs, larval, and pupal specimens become one of the most reliable indices for the age determination of a carcass [21,22]. This is achieved by three methods: (1) calculating the accumulated degree day/hour units, (2) referring to life history tables, and (3) using species-specific isomegalen/isomorphen curves [23]. In addition, the minPMI in advanced stages of decomposition can be estimated by assessing the succession patterns of flies and other carrion-associated invertebrates, although this is generally less accurate [24].…”

“…Adult-level identification has a greater certainty in correct species determination, and they are well-described in taxonomic keys [145]. When rearing dipteran species in an insectary, they should be confined in insect cages and provided ad libitum with food, water, and oviposition substrates [17,23].…”

The influence of altitude on the abundance and occurrence of species of the family Calliphoridae (Diptera) in corpses in a Mediterranean area

“…This is because its species are common, widely distributed, abundant, and are generally the first colonizers of a dead body. In many cases, they have the ability to detect a corpse from great distances [1][2][3][4][5][6]. Although Calliphoridae are ubiquitous, the abundance and colonization times of specific species may vary depending on the environmental conditions where a corpse is found.…”