Forensic entomology: a new hypothesis for the chronological succession pattern of necrophagous insect on human corpses

Abstract

Abstract. Forensic entomology can help to estimate the time elapsed since death, by studying the necrophagous species collected on a cadaver and its surroundings. The determination of the socalled post mortem interval (PMI or period of fi rst oviposition) is based on the development time of necrophagous dipterans and on the chronological pattern of insects' succession on the corpse throughout the decaying process. In the present study, authors investigated this succession by the analysis of the database of the Department of Forensic Entomology of the French Gendarmerie over 12 years (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003) in order to propose a new approach and a new hypothsesis of the dynamic of necrophagous insects' populations present on a human cadaver over time. For all treated cases, the presence/absence and the oldest development stage of the species were recorded. Data were analyzed by statistical and Wagner parsimony methods. The statistic results allowed the association of groups of species with typical developmental stages. The Wagner parsimony analysis showed that the dynamic of the necrophagous insect population present on a cadaver could be characterised by specifi c species. Together, they allowed establishing hypotheses of succession of necrophagous insects on human cadavers over time that could be usefull in the PMI estimation.Résumé. Entomologie forensique : une nouvelle hypothèse de succession chronologique d'insectes nécrophages sur les cadavres humains. L'entomologie légale permet d'estimer le temps écoulé depuis la mort grâce à l'étude des insectes nécrophages collectés sur un cadavre et dans son environnement. La détermination du délai post-mortem (Post Mortem Interval ou PMI) ou de la période de première oviposition (ponte) est basée sur l'étude des temps de développement des Diptères nécrophages et de la succession des insectes sur le corps en fonction des états de décomposition. Dans cette étude, nous analysons la succession des insectes nécrophages provenant de la base de données du Département d'Entomologie de l'Institut de Recherche Criminelle de la Gendarmerie Nationale (IRCGN) au travers de 12 années d'activité (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003). Le but de cette étude est de proposer une nouvelle approche et une nouvelle hypothèse de la dynamique des populations d'insectes nécrophages présents sur un cadavre au cours du temps. La présence/absence et le stade de développement le plus ancien par espèce sont recensés. Les données sont analysées statistiquement et par la méthode de la parcimonie de Wagner. L'analyse statistique met en évidence des associations d'espèces en fonction de stades types de développement. La parcimonie de Wagner montre que la dynamique des populations d'insectes nécrophages présents sur un cadavre, peut être caractérisée par la présence de certaines espèces. Elle permet également d'établir des hypothèses sur la succession des insectes sur les cadavres humains au cours du temps, pouvant être...

A catalogue of Coleoptera specimens with potential forensic interest in the Goulandris Natural History Museum collection

“…htm), species that were collected from crime scenes (Lefebvre & Gaudry 2009), or using beef as bait (Oliva 2001). The selected Families are: Silphidae, Staphylinidae, Histeridae, Ptinidae, Cleridae, Dermestidae and Nitidulidae.…”

“…The insects recovered from a crime scene can provide vital information for the investigation team and can help to estimate the time elapsed since death by studying the necrophagous insects collected on a cadaver and its surroundings (Aggarwal 2005). Two insect orders are the most important in forensic entomology, Diptera and Coleoptera (Oliva 2001, Lefebvre and Gaudry 2009, Çoban and Beyarslan 2013, Açikgöz 2016. Most forensic studies are focused on Diptera pattern colonization while neglecting Coleoptera succession (Dekeirsschieter et al 2013).…”

Impact of dike age on biodiversity and functional composition of soilmacrofaunal communities in poplar forests in a reclaimed coastal area

“…In forests with long dike histories, the abundance and taxa richness of the phytophagous and saprophagous groups increased, whereas the taxa richness of the omnivorous group and the abundance of the predaceous group did not significantly change (Table 4). These phenomena and the χ 2 results on the functional composition of soil macrofaunal communities (Table 5) suggest that soil environment provides different food resources in habitats with different dike histories, which cause significant changes in the functional composition of soil macrofaunal communities (Lefebvre and Gaudry, 2009).…”

“…Functional groups were also distinguished on the basis of food resources (Lefebvre and Gaudry, 2009). In forests with long dike histories, the abundance and taxa richness of the phytophagous and saprophagous groups increased, whereas the taxa richness of the omnivorous group and the abundance of the predaceous group did not significantly change (Table 4).…”

“…The macrofauna were classified into different functional groups on the basis of diet. Saprophagous, phytophagous, predaceous, and omnivorous groups were considered in this research (Lefebvre and Gaudry, 2009). …”