Genus Linepithema (Dolichoderinae)

• Linepithema Mayr, G. 1866a: 496 . Type species: Linepithema fusca Mayr, by monotypy.

• OVERVIEW.   This is a Neotropical genus with 14 species. Its members are adventive worldwide in warm or temperate areas. They are generalized foragers (Brown, 2000: 56 in Agosti, Majer, et. al. Ants, standard methods for measuring and monitoring biodiversity).
• ZOOGEOGRAPHICAL REGIONS.  New World.
• NOMENCLATURE.   Prior to 1992, the Nearctic species of Linepithema were placed in Iridomyrmex.
• RECOGNITION.   Mandible with 5 to 8 teeth and 5 to 13 denticles; the apical and subapical teeth prominent and notably larger than the succeeding teeth; third, fourth, and basal teeth separated by numerous denticles. Anterior margin of clypeus with a broad, shallow concavity. In profile, propodeum forms a prominent, rounded convexity that is relatively distinct from the profile of the remainder of the mesosoma. Metanotal impression distinct. Propodeum with basal face as long as or longer than declivitous face; in lateral view, the juncture of the two faces usually evenly convex (rarely weakly angulate). Erect hairs on body few.



Figure of Linepithema humile from Smith, M.R. 1965.


• SIMILAR GENERA.   Forelius is most similar to Linepithema, and the two genera can be separated by the following characters:
  

  	Forelius	Linepithema
  Hairs on anterior margin of clypeus	Long and ventrally curved	Shorter and straight
  Basal margin of mandible	Without denticles	With denticles
  First gastral tergite	Overhanging petiole	Not overhanging petiole

• TRIBE.  Dolichoderini.
• REVISIONS.   Shattuck, 1992c: 114–121 , figs. 104–110, tables 5–6 (description of w.q.m., diagnosis of l., distribution map, figures (full face and lateral views) of w.q.m.) .
• TAXONOMY.   Shattuck, 1999: 76–77, figs. 357–359.—Ward, P.& Brady, S. 2003: 76–77, figs. 357–359.

• humile. Hypoclinea humilis Mayr, G. 1868b: 164 (w.) . [Argentina] Forel, 1908h: 395 (m.) . Combination in H. (Iridomyrmex): Mayr, 1870b: 959; in Iridomyrmex: Emery, 1888d: 386; in Linepithema: Shattuck, 1992a: 16. Current subspecies nominal plus angulatum, arrogans, breviscapum, gallardoi, platense, scotti. Note that the original material is '(w.)' not '(q.)' as in Smith, D.R. 1979: 1418.

• DISTRIBUTION. MD to FL, west to IL, TX, AZ, CA; Mexico, S. Amer.; Europe; S. Africa; Hawaii; Australia (Smith, D.R. 1979: 1418).
• NOMENCLATURE. Prior to 1992, this species was named Iridomyrmex humilis Mayr, 1868.
• TAXONOMY. Wheeler, W.M. 1913: 27–30 (description w.q.m.) .— Gallardo, 1916b: 97.— Smith, M.R. 1929b: 241.— Creighton, 1950a: 341–342 .— Smith, M.R. 1965: 52–54, fig. 28 (diagnosis of w., natural history, figure (lateral view) w., as Iridomyrmex humilis) .— Wheeler, G.C. & Wheeler, J. 1966: 729 (larva) .— Bernard, 1967a: 251.— Wilson & Taylor, 1967b: 79–80 (Polynesia) .— Collingwood, 1979: 33–34, figs. 20, 21 (diagnosis of w.q.m., natural history, figure (lateral view) w.m.) .— Ward, 1987: 1.— Wheeler, G.C. & Wheeler, J. 1990a: 465–466, fig. 9 (l.) .— Bolton, 1994: figs. 40, 41 (SEMs (full face and lateral view) of w.) .— Shattuck, 1994: 123.

• nigellum. Iridomyrmex iniquus var. nigellus Emery, 1890c: 56 (w.) . [Costa Rica] Combination in Linepithema: Shattuck, 1992a: 16. Subspecies / race of disperitum: Forel, 1901d: 134; Forel, 1912i: 47. Subspecies / race of iniquum: Creighton, 1950a: 342. Also described as new by Emery, 1894k: 61.

• DISTRIBUTION. MA, IL and other scattered localities mostly in northeastern USA; Central Amer.
• TAXONOMY. Creighton, 1950a: 342 .
• MISCELLANEOUS. Smith, M.R. 1929b: 241–242.— Wheeler, W.M. 1929c: 89–90.