Post-mortem Interval Estimation in a Forensic Case with Two Predatory Species: Chrysomya albiceps and Synthesiomyia nudiseta

Anabel Martínez-Sánchez,Salvador Giner Alberola,Tania Ivorra

doi:10.24191/jchs.v6i1(special).13996

Abstract

A forensic case in which two facultative predatory species were found together on a human corpse is presented in this work. Second and third instar larvae of Synthesiomyia nudiseta (van der Wulp, 1883) (Diptera: Muscidae) and Chrysomya albiceps (Wiedemann, 1819) (Diptera: Calliphoridae) were collected from the dead body of a man on 14th November 2019, but puparia in the autopsy pictures were observed after, but not collected. The corpse was found on the terrace of the third floor of a building located in the town of Elche (SE Spain), and the pathologist confirmed the death as natural. The minimum post-mortem interval was estimated by the time to reach the length of the collected larvae or to reach the pupal developmental stage (in days and accumulated degree-days). In accordance with the influence of the predatory behaviour of each of these species on the developmental data of the other, as described in the existing literature, the effect of a hypothetical competition between both species on post-mortem interval was discussed.

Highlights

There are many different interactions between the fauna on a corpse, such as competition between or predation on the larvae of necrophagous species of Diptera [1,2,3]
intraguild predation (IGP) can take place between individuals of the same species, or between individuals of different species; and on carcasses, IGP should be taken into account in the estimation of post-mortem interval based on the entomological evidence, but at present few reports about forensic cases of this nature have been published
In the case of C. albiceps, with the data of Marchenko [16], 123.00 Accumulated Degree-Days (ADD) were obtained from egg to pupariation at 17oC, with a 10.2oC lower threshold, so the corpse was exposed to its activity 18.1 days before autopsy, and attending to ADDs, the value 123.00 ADD is obtained on 28th October (Table 2)

Summary

INTRODUCTION

There are many different interactions between the fauna on a corpse, such as competition between or predation on the larvae of necrophagous species of Diptera [1,2,3]. In the case of C. albiceps, with the data of Marchenko [16], 123.00 ADD were obtained from egg to pupariation at 17oC, with a 10.2oC lower threshold, so the corpse was exposed to its activity 18.1 days before autopsy, and attending to ADDs, the value 123.00 ADD is obtained on 28th October (Table 2). These results are compatible to what was observed in the previous analysis using measurements or development stages, so we concluded that the ranges of the two species overlap

DISCUSSION

CONCLUSION