Linepithema humile

Distribution
This introduced species occurs sporadically throughout Florida, in places forming massive populations. It occurs in both moist and dry open habitats, usually in heavily disturbed sites. Pest status: can become a nuisance by sheer numbers, trailing long distances to outdoor eating areas and into buildings. First published Florida record: Wheeler 1932; earlier specimens: 1914. (Deyrup, Davis & Cover, 2000.)

Distribution based on Regional Taxon Lists
Afrotropical Region: Lesotho, Mozambique, Namibia, Saint Helena, United Arab Emirates. Australasian Region: Australia, New Zealand, Norfolk Island. Indo-Australian Region: Hawaii, Vanuatu. Nearctic Region: United States. Neotropical Region: Argentina, Bermuda, Brazil, Colombia, Ecuador, French Guiana, Mexico, Paraguay, Uruguay. Palaearctic Region: Balearic Islands, Belgium, Bulgaria, Canary Islands, Channel Islands, Democratic Peoples Republic of Korea, France, Germany, Gibraltar, Greece, Iberian Peninsula, Iran, Japan, Malta, Monaco, Montenegro, Poland, Portugal, Spain, United Kingdom of Great Britain and Northern Ireland.



Europe
This species was introduced into Europe from South America and has become an established and notorious pest in the Mediterranean area, developing very populous multi-queened colonies along the coast. It is sometimes brought into North Europe with plant materials and occasionally colonises heated premises. It does not appear to be able to establish outside in northern latitudes but is present and said to be increasing in the Channel Islands. (Collingwood 1979)

Castes
Queens differ in their Cuticular Hydrocarbons according to ovarian activity. Whereas the cuticular profile of non-laying queens is similar to that of sterile workers, it gradually changes both qualitatively and quantitatively once queens start to lay eggs. These changes are independent of mating status, since virgin egg-laying queens show a CH profile similar to that of mated egg-laying queens (de Biseau et al. 2004).

Nomenclature

 *  humile. Hypoclinea humilis Mayr, 1868b: 164 (w.) ARGENTINA. Forel, 1908c: 395 (m.); Newell, 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, 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, 2007a: 61; Solis, Fox, Rossi & Bueno, 2010: 19.
 * arrogans. Iridomyrmex humilis var. arrogans Chopard, 1921: 237 (footnote),:241, figs. 1-31 (w.q.m.l.) FRANCE. [Also described as new by Santschi, 1929d: 306 (in key).] Combination in Linepithema: Shattuck, 1992a: 16. Junior synonym of humile: Bernard, 1967: 251. Revived from synonymy as subspecies of humile: Shattuck, 1992a: 16. Junior synonym of humile: Wild, 2004: 1207.
 * riograndensis. Iridomyrmex riograndensis Borgmeier, 1928b: 64 (w.) BRAZIL. Combination in Linepithema: Shattuck, 1992a: 16. Junior synonym of humile: Wild, 2004: 1207.