INSECTS’ SUCCESSION ON THE DECOMPOSING PIG CARRION DURING THE WET SEASON AT THE COLLEGE OF EDUCATION, DELTA STATE, NIGERIA
The sequence of insects’ succession on decaying pig carrions were studied at the Biological garden of the College of Education, Warri South Local Government Area, Delta State from 10th June to August 10th 2017 to document the successive wave of insects recovered on the decomposing pig carrions. Pigs of mean weight of 23.18±0.42 were used as animal model to mimic human cadaver in study. Three pigs were stabbed in the thorax, under the foreleg with a sharp knife to simulate a typical homicide wound; each killing was around 6.00pm daily before the commencement of the study. Sampling for the entomofauna was carried out twice for the first week while twice at the other weeks, second instars larvae were reared till adult stages Component bar charts were used to demonstrate the succession of different orders of insects, Multiple bar charts were used to show the frequencies of the insects in each stage of decomposition, pie chart was used equally to show the period of each stage of decomposition while Principle Component Analysis was used to show the distribution of insects in the different
decomposition stages. While component 1 accounted for 47.9 of the variation of the data, component 2 accounted for 30.80% making a total of 78.70%. At the fresh stage of decomposition, 223 insects were recorded, at the bloated, 314 were recorded, at the active decay stage, 328 were recorded, at the advanced decay stage 405 were recorded but at the dry decay stage only 158 were recorded, making it a total of 1428 insects recorded. Out of the whole period of decomposition, fresh stage took 2%, bloated stage took 3%, active stage was also for just a period of 8%, advanced decay stage was 7% while the dry decay stage lasted for 80% respectively, however it is recommended that more research works be carried out in Warri City and its environment so as to create a dependable data base of forensically important insects in the oil rich city.