Dolichoderinae

This subfamily contains some of the most common and well-known species of Australian ants. This includes the genus Iridomyrmex, a group found throughout Australia, often in very large numbers. Some of the rarer Australian ants are also in this subfamily. For example, Nebothriomyrmex majeri has been collected fewer than 10 times. A significant introduced pest, the Argentine ant (Linepithema humile), is also a dolichoderine.

Most species of Dolichoderinae are general predators or scavengers. Many also tend Hemiptera to collect honeydew or are associated with caterpillars. Nests are found in a wide variety of locations, including in the soil, under rocks and other objects, in rotten and living wood, in termite mounds, and in cracks between rocks. Some species (in the genus Arnoldius) are thought to establish their nests by new queens invading the nests of other ants, killing the queen, and using the captured workers to help raise her own offspring.

Species of Dolichoderinae can be found in most regions of the world and in all major habitats. There are about 1000 described species and subspecies placed in 26 genera world-wide. Fifteen genera and over 160 species and subspecies have been described from Australia, with numerous taxa still awaiting description. Four of the genera, Arnoldius, Doleromyrma, Froggattella and Nebothriomyrmex, are only known from Australia. The relationships among these genera have been well documented (see Phylogeny of Dolichoderinae).

The Dolichoderines lack a sting, but are armed with defensive compounds produced by the anal gland - a structure unique to the subfamily. This is the source of the pungent, and often unpleasant odors produced by many species when they are disturbed, crushed or otherwise annoyed. In many species colonies may be polygynous and/or polydomous. Some are predaceous, but most appear to be generalized scavengers with a strong liking for carbohydrates taken directly or indirectly from plant sources. In addition to founding colonies via single newly mated queens, some produce new colonies by budding or fission. Most Dolichoderines are free-living; a few are social parasites on other members of their subfamily.

Identification
The mesosoma is attached to the gaster by a single distinct segment, the petiole. The gaster is smooth, without constrictions between the segments. The sting is absent and the tip of the gaster is slit-like and without a circular opening (an acidopore).

Species of Dolichoderinae are most often confused with species of the subfamily Formicinae because both have a single segmented petiole, lack a sting and are often similar in overall body size and shape This is especially true for the smaller species such as those in Doleromyrma and Tapinoma. However, dolichoderines can always be separated from formicines because the tip of the gaster has a slit-like opening while all formicines have a small circular opening.

Regional Identification Keys
Australian Dolichoderinae Genera