NCJ Number
198018
Journal
Canadian Society of Forensic Science Journal Volume: 35 Issue: 3 Dated: September 2002 Pages: 145-152
Date Published
September 2002
Length
8 pages
Annotation
This study recorded the carrion insect species composition that colonized pig carcasses placed at sites in Nova Scotia from September to November.
Abstract
Such information is important in death investigations, because determination of maggot age on a body can be used to estimate time-since-death or postmortem interval. The accuracy of such predictions requires an accurate knowledge of the biology of the species indigenous to the geographic area in which a body is found. Factors such as season, geographic location, climate, and local fly population densities will determine what species will colonize dead bodies in a given area. In the current study, three pigs were placed at each of two wooded sites in the city of Halifax, and six were placed at two sites in the forest at Long Lake Provincial Park on the outskirts of the city. Pigs of different weights and sizes were distributed evenly among the four sites. The sites were visited daily from September 23 (city sites) and September 25 (park sites) to October 18, and then every other day until the ground was frozen in early November. The amount of time the carcasses spent in each stage of decomposition was recorded. Sweep-net, pitfall trap, and manual collections of eggs, maggots, and adults were made for 20 days between September 23 and October 18, after which the pigs were almost completely decomposed, and all insect activity had ceased due to low temperatures. Findings indicate that species in the genus Calliphora were the most commonly present at the carcasses. Adults of a Dryomyza sp. (Dryomyzidae) were also common on the carcasses, but were not reared from maggot samples collected from the pigs. Other carrion insects such as burying beetles (Silphidae) were also collected. 3 figures and 22 references