Development Of Four Species Of Forensic Flies, Estimation Of Post-Mortem Interval And Their Application On Forensic Cases In North Peninsular Malaysia
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Date
2011-07
Authors
Krishnan, Kumara Thevan
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
The current study explores the relation of the forensic insects and human
corpses during the period July 2007 until July 2010 in North Peninsular Malaysia.
The larvae were sampled and taken into laboratory, where 50 % of the larvae reared
on beef meat ad libitum and the other 50 % killed in warm water (52 ± 10 ºC) and
preserved in Kahle’s solution. The species confirmations were done when the reared
case maggots emerged. The frequency of occurrence (FO) and dominance (D) of
forensic flies were calculated for indoor and outdoor environments. The adults of C.
megacephala, C. rufifacies, Liosarcophaga dux and S. nudiseta were maintained as
colony and their immature life cycle were established. Then, modeling equations was
established for each species using general linear model (GLM). Based on the
established life cycle and the models equations, the postmortem estimates were
determined for each case using mean larval length, larval stage, accumulated degree
hour (ADH) and modeling equations.
The total number of fly specimens sampled was 154 specimens with 95
specimens sampled from 27 indoor corpses and 59 specimens from 23 outdoor cases.
Current study reported first case record of three species in Malaysia (beetles -
Dermestes ater, Dermestes maculatus and fly - Desmometopa sp.) and two first
report species in the world (Megaselia curtineura (Brues), Megaselia spiracularis
Schmitz) sampled from human corpses. For the indoor environment there are four
dominant families (Calliphoridae, Sarcophagidae, Muscidae and Phoridae) with the
Calliphoridae was the most frequent family amongst the four families, whereas for
outdoor environment only one dominant family which was Calliphoridae. The
immature developmental time from eggs/first instar until emergence stages for C.
megacephala, C. rufifacies, Liosarcophaga dux and S. nudiseta was 218 ± 12 hours,
206 hours, 307 ± 3 hours, and 337 ± 4 hours, respectively. Modelling study found the
error between the actual and predicted accumulated developmental time in
established models was 0.5 – 24.2 %, 0.8 – 19.3 %, 6.2 – 26.3 %, and 1.8 – 14.9 %,
depending on the larval stages for C. megacephala, C. rufifacies, Liosarcophaga dux
and S. nudiseta, respectively. The differences of PMI estimates among the four
methods was not significant (F3,184 2.36, p = 0.07). However, ADH must only be
used when the temperature records experience by the larvae was available.
Description
Keywords
The forensic insects and human corpses , the period July 2007 until July 2010