Impact of confinement in vehicle trunks on decomposition and entomological colonization of carcasses

Abstract

In order to investigate the impact of confinement in a car trunk on decomposition and insect colonization of carcasses, three freshly killed pig (Sus scrofa domesticus Erxleben) carcasses were placed individually in the trunks of older model cars and deployed in a forested area in the southwestern region of British Columbia, Canada, together with three freshly killed carcasses which were exposed in insect-accessible protective cages in the same forest. Decomposition rate and insect colonization of all carcasses were examined twice a week for four weeks. The exposed carcasses were colonized immediately by Calliphora latifrons Hough and Calliphora vomitoria (L.) followed by Lucilia illustris (Meigen), Phormia regina (Meigen) and Protophormia terraenovae (R.-D.) (Diptera: Calliphoridae). There was a delay of three to six days before the confined carcasses were colonized, first by P. regina, followed by Pr. terraenovae. These species represented the vast majority of blow fly species on the confined carcasses. Despite the delay in colonization, decomposition progressed much more rapidly in two of the confined carcasses in comparison with the exposed carcasses due to the greatly increased temperatures inside the vehicles, with the complete skeletonization of two of the confined carcasses ocurring between nine and 13 days after death. One confined carcass was an anomaly, attracting much fewer insects, supporting fewer larval calliphorids and decomposing much more slowly than other carcasses, despite similarly increased temperatures. It was later discovered that the vehicle in which this carcass was confined had a solid metal fire wall between the passenger area and the trunk, which served to reduce insect access and release of odors. These data may be extremely valuable when analyzing cadavers found inside vehicle trunks. Highlights • Confinement of pig carcasses inside car trunks in southwestern British Columbia, Canada delayed blow fly colonization by three to six days • Temperatures inside cars were much higher than ambient temperatures and speeded up decomposition of the confined carcasses

High Temperature Limits of Survival and Oviposition of Phormia regina (Meigen) and Lucilia sericata (Meigen)

“…This investigation found even with vehicle color accounted for, sealed cabin temperatures can dramatically exceed the environmental ones [33]. The Australian and Canadian experiments both noted accelerated decomposition catalyzed by higher temperatures within the cars, compared to outer ambient temperatures [5,31]. The ratio of pupae to adult flies remaining trapped within the vehicle led Malainey & Anderson [31] to conclude the adult flies were likely incapable of egress from the space.…”

“…Carrion concealed or within a confined space can present a barrier to primary colonization by calliphorids. Field trials of Sus scrofa concealed in automobile trunks in Louisiana, USA and Vancouver, Canada demonstrated delayed colonization by 3 days and 3-6 days, respectively [5,31]. Australian field trials of S. scrofa in the car driver's seat demonstrated delayed colonization by ~1 day [32].…”

“…The Australian and Canadian experiments both noted accelerated decomposition catalyzed by higher temperatures within the cars, compared to outer ambient temperatures [5,31]. The ratio of pupae to adult flies remaining trapped within the vehicle led Malainey & Anderson [31] to conclude the adult flies were likely incapable of egress from the space. This demonstrates situations where adult flies may become trapped within the high temperature arena.…”

Use of thermal drone in detection and assessment of larval mass temperature in decomposed rabbit carcasses

“…Earlier studies have demonstrated that clothed carcasses have a faster decomposition rate due to greater insect diversity and feeding activity than unclothed carcasses [22][23][24]. However, some studies have reported contrasting results that clothing affects insect activities negatively and hence delays the decomposition process [22,25]. The inconsistency and paucity of data detailing insect activities associated with clothed and unclothed carcasses in tropical climates remain to be investigated.…”

Estimation of PMI for human remains wrapped in a blanket, with first report of Puliciphora rufipes (Phoridae) and Synthesiomyia nudiseta (Muscidae) outdoors in SE Spain

“…However, the impact of this and other access factors, e.g. burial, being indoor and being in a suitcase [3,4], have not been studied in any depth in Europe. In this context, the present study reports the case of a homeless man whose corpse was found outdoors, wrapped up to the neck in a blanket.…”