Threat Level: Low

Pachycondyla stigma is a relatively large, robust ant with strong mandibles, a thick petiole and a minute pair of eyes. As a member of the Ponerinae, it has a single waist segment, a sting and a broad set of frontal lobes.

Of the other ponerines included in PIAkey, Odontomachus simillimus can be separated from P. stigma by its linear mandibles, peculiar head shape and pointed petiolar node. Species in the genus Hypoponera are more difficult to differentiate with P. stigma because both have approximately similar head shapes and body shapes. Hypoponera species included in PIAkey can be separated from P. stigma by their smaller size, greater number of mandibular teeth, and narrower frontal lobes. The presence of a simple tibial spine in addition to the pectinate tibial spine is the most reliable character used to separate the two genera, but it can be difficult to recognize under the microscope.

Pachycondyla stigma is described by Wilson and Taylor (1967) as one of the most widespread ponerines in the world. It occurs widely across the Pacific Island region, but is mostly limited to forested habitat where it nests and forages in and around rotting logs, soil and leaf litter. The species is almost entirely blind, and is not often encountered foraging out in the open, nor is it known to recruit to food baits. Although Pachycondyla stigma is considered an introduced species, it is not commonly regarded as a pest species, and little is known about the effects the species has on native biological diversity.

Waist with one segment (petiole)
Gaster armed with sting
Frontal lobes present Frontal lobes broad
Mandibles triangular, with many teeth of different sizes
Hind tibia with pectinate spur and simple spur present
Antennal scape reaching or exceeding posterior margin of head

	P. stigma	H. opaciceps	H. punctatissima
Head
Profile
Mandibles	with five teeth of approximately equal size	with more than five teeth of different sizes	with more than five teeth of different sizes
Frontal lobes	broad	narrow	narrow
Hind tibia	with pectinate and simple spur	with only pectinate spur	with only pectinate spur
	P. stigma	H. opaciceps	H. punctatissima

• Antweb: specimen images, data & maps
  
  
• Bolton, B. (1995) A new general catalogue of the ants of the world. Harvard University Press, Cambridge, Massachusetts, 504 pp.
  
  
• Wilson, E.O. & Taylor, R.W. (1967) The ants of Polynesia (Hymenoptera: Formicidae). Pacific Insects Monograph, 14, 1-109. [Referred to as Trachymesopus stigma]