Odontomachus rixosus Smith, 1857, belongs to the genus Odontomachus, subfamily of Ponerinae and tribe Ponerini (Schmidt & Shattuck, 2014) is a forest species that widely distributed throughout tropical Asia and can be found in the forest of Peninsular Malaysia and Borneo. The name Odontomachus derived from the Ancient Greek which literal meaning of odonto is “tooth” and machus means “thrower” due to the presence of its prominent mandibles.
The elongated mandible is massive and lies nearly parallel to the head when fully closed and usually held open to about 180° in ready position. The genus Odontomachus is known as trap-jaw ants due to their predatory mandible strike. The powerful and rapid mandible strike has been recorded to be the fastest self-powered predatory strike in the animal kingdom at 35 to 64 meters per second (Gronenberg, 1995).
Odontomachus rixosus worker morphology are broad pyriform head with eyes situated far apart on lateral side. The petiolar node is conical, with sharply pointed apical spine. The body when observe at the lateral view is relatively slender and long. Like all ants, O. rixosus are eusocial insects which mean that the ants live in a cooperative group called a colony and most of the individual aid the reproductive members or the queens for the success of reproduction. Their colony is polygynous, which means it is reigned by multiple dealate queens of average 25 queens in a single colony (Ito et al., 1996). Queens are responsible not just for egg-laying and egg-care, but also for larval and pupal care, nest wall maintenance, and nest cleaning. They are also capable of foraging outside the nest and bring the caught prey inside the nest chamber.
This ant species is commonly found within the rainforest of South East Asian region. In Malaysia, this ant species has been found inhabits primary, secondary forests and also has been recorded to be present at plantations adjacent to forested areas in lowlands. This species typically nests and forage under leaf litter, in the soil near the base of living trees, and under rotten logs and stumps. O. rixosus are efficient solitary predators and they are generalist predators of arthropods, particularly termites since it is found abundant around their nests (Schmidt & Shattuck 2014). The ants may strike prey items multiple times using their mandible to break up large items into more manageable fragments. Since ants are recognized as important predator in most terrestrial communities, O. rixosus might play important role for pest management in decimating the small arthropods number.
