Acropyga

These small ants are most often encountered in leaf litter or when nests are located, and less commonly foraging on low vegetation. A few species are exclusively subterranean. Nests are known from a range of sites, including in soil with or without coverings or in plant roots, under bark on trees and in rotten logs. Because of their small size and cryptic nesting habits they are often overlooked.

Most species appear to have close relationships with coccids, aphids and mealybugs (order Hemiptera). These Hemiptera feed on the roots of plants and produce secretions (honeydew) which the ants collect and use as a food source. In some cases this relationship has developed to such an extent that the Hemiptera are known only from the ant's nests. To insure that new nests are supplied with these specific Hemiptera, new queens carry fertile female Hemiptera in their mandibles during their nuptual flight, establishing a new Hemiptera colony along with her new ant colony.



Worker of A. acutiventris from Queensland.



Acropyga queen on her nuptual flight carrying a mealybug in her mandibles.

Identification
The antennae have 8, 10 or 11 segments (including the scape) with 10 or 11 being the most common. The palps are short, do not extend along the under side of the head and have a formula of 5:3 or less (outer or maxillary palps with 5 segments, inner or labial palps with 3 segments) (down to at least 2:3). The compound eyes are small (less than the width of the antennal scape), with at most about 30 individual facets (ommatidia) but often with only 4 to 6, or are completely absent. The mandibles have 3 to 5 teeth. The petiolar node is present and distinct although relatively low and thin. The body colour is yellow to yellowish-brown.

Species of Acropyga are small ants (less than 4 mm long) with a compact, stocky body. They can be separated from other formicines by their small eyes, short palps with a palp formula of 5:3 or less, and in having only 3 to 5 mandibular teeth. They are most often confused with small species of Doleromyrma and Tapinoma (both in the subfamily Dolichoderinae) and Plagiolepis because of their small size and similar overall body shape. However, they can be separated using the characters listed above.

Distribution and Habitats
Australian distribution

Regional Species Lists

 * Australia

Keys to Species

 * Australia