Succession of Dipteran Fly Maggots on Poisoned Pig Cadavers at Nnamdi Azikiwe University, Awka, Nigeria

Abstract

Dipteran maggots found on a cadaver are used to estimate its time of death but the time may be incorrect if death occurred due to ingestion of poison. Decomposition of a zinc phosphide intoxicated and strangulated pigs (Sus scrofa Linn.) were evaluated in this study. They were deposited in a forest during the rainy season and repeated during the dry season at Awka, Nigeria. Decomposition duration and stages of decay of the pig cadavers were recorded. Maggots found on the cadavers were collected, reared to adulthood and were identified. Similar maggot samples were assessed for residues of zinc and phosphorus with an Atomic Absorption Spectrophotometer. Both pig cadavers completely decomposed within 10 and 14 days during the rainy and dry seasons, respectively. Appearance and emergence of three dipteran maggot families were observed on the cadavers in a successional pattern. Zinc and phosphorus residues were detected in the maggots from the poisoned cadavers while they were not detected in the maggots from the strangled cadavers. The three dipteran maggot families are recommended as a valuable tool in forensic entomology for the estimation of elapsed time of a questionable death and the dipteran bodies would also be useful for toxicological analysis.