Studies documenting insect succession throughout the decomposition of vertebrate remains have been performed in more than half of the provinces and one territory in Canada. However, some areas are not represented in the current published literature. Ontario is one province that does not have published records of local necrophagous insect succession. Therefore, three studies were performed in Oshawa, Ontario, to document the insect community and primary colonisers observed during the decomposition of domestic pig, Sus scrofa domestica (Artiodactyla: Suidae), remains. Adult and immature specimens located on the remains were collected, reared, and identified. Pitfall traps were installed to monitor insects present outside of visits. Pigs that decomposed in higher temperatures yielded fewer colonising dipteran species than those that decomposed in cooler temperatures. The most common primary colonisers were Phormia regina (Diptera: Calliphoridae), Lucilia illustris (Diptera: Calliphoridae), and Lucilia sericata (Diptera: Calliphoridae). In total, 11 Diptera families, six Coleoptera families, and families from the Hymenoptera and Hemiptera orders were observed. When comparing these results to published results from Québec, Ontario’s neighbour, major differences in primary colonisers can be noted. It is therefore important for researchers to study the succession, development, and colonisation patterns of the local fauna during vertebrate decomposition and to publish their findings.