Insects Associated with Decomposing Pig Carrions in Okija, Anambra State, Nigeria.

Abstract

Insects associated with decomposing pig carrions were studied in an open fallow plot in Okija, Anambra state, Nigeria. The decomposition process of the carrions took sixteen days in the four phases - fresh, bloated, active and dry decay stages. Six orders of insects- Diptera, Coleoptera, Hymenoptera, Hemiptera, Orthoptera and Dictyoptera were collected on the carrions. The sarcophagids and calliphorids were the first to arrive on the carrions and deposited their first instar larvae and eggs respectively, few hours after death, during the fresh stage. The dermestids and clerids arrived on the carrions few days after death during the bloated stage. The ulidiids and stratiomyiids arrived on the carrions during the active decay stage. The insect species composition on the carrions peaked during the active decay stage. The larvae of these insects fed voraciously on the carrions, which led to faster decomposition of the carrions. The arrival of the dipterans and the coleopterans were predictable and their importance as forensic insects were discussed. The probable reason for the occurrence of hymenopterans, hemipterans, orthopterans and dictyopterans on the carrions were also given.