About Iridomyrmex rufoniger (Lowne, 1865)
Iridomyrmex rufoniger (Lowne, 1865) belongs to the Iridomyrmex purpureus species group, and is one of the most familiar ant species to the Australian public. Typical worker ants are medium-sized relative to other members of their genus. They have a broad head, and their gaster displays blue or yellowish-green iridescence. Colonies found in Sydney show distinct variation; these individuals have a dark coloration and small heads, which is an atypical trait compared to Iridomyrmex rufoniger colonies from other parts of Australia. This ant is abundant across every Australian state and territory, though it is rare in the Northern Territory. It also occurs in the Solomon Islands and New Caledonia, where it may be an introduced species. It was introduced to New Zealand after being intercepted at the ports of Auckland and Freyberg, but has not become formally established in the country. Nests of Iridomyrmex rufoniger are numerous, and are built in soil. Depending on location, this species can act as a dominant ant. Numerous colonies have established in mine dumps in Westonia, Western Australia, but the species is not common in the surrounding rehabilitated bushland. Nests are most often found in loose dirt or under stones. Based on collected specimens, this ant occurs at elevations ranging from 5 to 1580 metres (16 feet to 5183 feet), with a mean collection elevation of 244 metres (800 feet).
