Linepithema humile

  • Synopsis
  • Diagnostic Characters
  • Comparison Chart
  • Images
  • Video
  • Nomenclature
  • References & Links

Threat Level: Medium

Linepithema humile is a small uniformly brown ant of dull appearance in the field that forms strong foraging trails to baits and other food resources. The species has a single, upright waist segment, 12-segmented antennae, eyes that lie within the outline of the face, and lacks an acidopore.

Linepithema humile can appear similar to several other Pacific invasive ants, including Iridomyrmex anceps, and Technomyrmex species. See the diagnostic characters and comparison charts for the best way to distinguish among them.

Commonly known as the Argentine ant, L. humile is among the most notorious invasive ants in the world. It has been shown to cause significant damage to native biological diversity and agricultural systems. The species is native to South America, but has established introduced populations across the globe. In the Pacific, it is currently known from the cooler regions of Australia, New Zealand and Hawaii. For a more complete review of the biology, impacts and management of L. humile, users are referred to the IUCN/SSC Invasive Species Specialist Group (ISSG) web page. The discovery of this species in a new locality may warrant a rapid management plan.

  • Waist with one segment (petiole)

  • Petiole raised, not flat
  • Gaster not armed with sting or acidopore
  • Eyes, in full face view, do not break outline of head
  • Dorsal surface of mesosoma without any erect hairs

Linepithema humile vs. Iridomyrmex anceps group and Technomyrmex spp.


L. humile I. anceps group Technomyrmex spp.


Dorsum of mesosoma with erect hairs



L. humile I. anceps group Technomyrmex spp.

Linepithema humile

Linepithema humile

Linepithema humile

No video is available for this species.


Subfamily Dolichoderinae

This species is often referred to as Iridomyrmex humilis in the literature prior to 1992.

Linepithema humile. Hypoclinea humilis Mayr, 1868b: 164 (w.) ARGENTINA. Forel, 1908c: 395 (m.); Newall, 1908: 28 (q.); Wheeler, G.C. & Wheeler, J. 1951: 186 (l.); Crozier, 1969: 250 (k.). Combination in H. (Iridomyrmex): Mayr, 1870b: 959; in Iridomyrmex: Emery, 1888d: 386; in Linepithema: Shattuck, 1992a: 16. Senior synonym of arrogans and riograndensis: Wild, 2004: 1207. See also: Gallardo, 1916a: 97; Bernard, 1967: 251; Collingwood, 1979: 33; Smith, D.R. 1979: 1418; Ward, 1987: 1; Wheeler, G.C. & Wheeler, J. 1990a: 465; Shattuck, 1994: 123; Wild, 2007: 61.

  • Antweb: specimen images, data & maps

  • Global Invasive Species Database: information about ecology, distribution, impacts, management, references, links and contacts

  • Bolton, B. (1995) A new general catalogue of the ants of the world. Harvard University Press, Cambridge, Massachusetts, 504 pp.

  • Wild, A.L. (2004) Taxonomy and distribution of the Argentine Ant, Linepithema humile (Hymenoptera: Formicidae). Annals of the Entomological Society of America, 97, 1204-1215.

  • Wilson, E.O. & Taylor, R.W. (1967) The ants of Polynesia (Hymenoptera: Formicidae). Pacific Insects Monograph, 14, 1-109. [referred to as Iridomyrmex humile]