Evaluation of activities of dipteran maggots on a poisoned pig cadaver at Nnamdi Azikiwe University Awka, Nigeria

Maduamaka Cyriacus Abajue,Sylvanus Chima Ewuim

doi:10.1186/s41935-020-00208-0

Maduamaka Cyriacus Abajue, Sylvanus Chima Ewuim

Open Access

https://doi.org/10.1186/s41935-020-00208-0

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Abstract

BackgroundForensic entomology is evolving into entomotoxicology, which is a critical approach in forensic toxicology that alternatively assesses presence of toxins in insects that have eaten a decomposing cadaver. Toxic substances in or on a dead body may accumulate in the tissues of fly maggots while feeding on the body and thus may alter their developmental rate. Thus, four out of eight healthy pigs (Sus scrofa Linn.) that weighed on the average 22.3 ± 1.9 kg were sacrificed with zinc phosphide as food poison, while the remaining four pigs were sacrificed by strangulation during the rainy and dry seasons of 2014 and 2015 respectively. Their bodies were deposited in a building to mimic indoor decomposition. The building is on 6° 15′ 18.06″ N and 7° 06′ 41.37″ E at Nnamdi Azikiwe University Awka, Anambra State, Nigeria. The effect of the zinc phosphide on the decomposition duration of the cadavers was monitored. Toxicological assessment of zinc and phosphorus on maggots found on the cadavers was performed with an atomic absorption spectrophotometer.FindingsThe zinc phosphide did not affect the decomposition duration of the cadaver and did not prolong or shortened the life cycle of the fly maggots when compared with the control (strangled pig cadaver). For the poisoned cadavers, the atomic absorption spectrophotometer detected zinc in the maggot tissues collected from them while phosphorus was not detected. Neither zinc nor phosphorus was detected in the maggot tissues collected from the strangled cadavers.ConclusionsThe study showed that the zinc component in the zinc phosphide commonly used as rodenticide in Awka can be detected in maggots collected from such a suspected poisoned cadaver. Other implications related to toxicological studies on cadaveric insects in forensic entomology and serving as alternative matrices in forensic toxicology in any questionable death were also highlighted.

Highlights

Forensic entomology is the use of the biological knowledge of insects in a death investigation when a cadaver has decomposed and infested with insects
* Correspondence: maduamaka.abajue@uniport.edu.ng 1Department of Animal and Environmental Biology, University of Port Harcourt, Port Harcourt, Nigeria Full list of author information is available at the end of the article which is a critical approach in forensic toxicology that alternatively assesses presence of toxins in insects that have eaten a decomposing cadaver
Toxic substances in or on a dead body may accumulate in the tissues of fly maggots while feeding on the body and may alter their developmental rate

Summary

Introduction

Forensic entomology is the use of the biological knowledge of insects in a death investigation when a cadaver has decomposed and infested with insects. The use of insects in death investigation has been extended in crime scenes on land and water (Keiper and Casamatta 2001; Hobischak and Anderson 2002) It is evolving into entomotoxicology, Toxic substances in or on a dead body may accumulate in the tissues of fly maggots while feeding on the body and may alter their developmental rate. Four out of eight healthy pigs (Sus scrofa Linn.) that weighed on the average 22.3 ± 1.9 kg were sacrificed with zinc phosphide as food poison, while the remaining four pigs were sacrificed by strangulation during the rainy and dry seasons of 2014 and 2015 respectively Their bodies were deposited in a building to mimic indoor decomposition. Toxicological assessment of zinc and phosphorus on maggots found on the cadavers was performed with an atomic absorption spectrophotometer

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Conclusion