Costa Rica south to the Brazilian Pantanal.
From Wild 2007:
Collection records of L. angulatum range across a broad array of habitats from sea level to over 2800 meters. Two collections are from leaf litter in montane forest, one under a stone in a montane forest edge, one under bark in second-growth forest, one in rotting wood, and two in high elevation urban parks in Colombia and Ecuador. Wheeler (1942: 214) reports this species (as ÒpordescensÓ) nesting in a Tillandsia bromeliad in Costa Rica. This species has been observed recruiting to tuna baits placed 30cm underground in Peru (M. Frederickson, pers. com), to surface sausage baits in Venezuela, and to surface tuna baits in the Pantanal (Orr et al. 2003). One collection records L. angulatum tending pseudococcids on Croton gossypifolia in Colombia and another tending root-aphids in a nest in Ecuador. Male alates have been taken in June in Ecuador and in December in Colombia.
A series of studies by Orr and various coauthors (Orr and Seike 1998, Orr et al. 2001, Orr et al. 2003) documented the interactions between L. angulatum (as ÒL. humileÓ or ÒL. piliferumÓ) and the phorid parasitoid Pseudacteon lontrae Mattos and Orr 2002 in the Pantanal. The presence of phorid flies significantly alters the behavior of this species in the field, leading to changes in the ecological dominance hierarchy in the ant community.
Linepithema angulatum has been intercepted several times with orchids in various ports of entry into the U.S., suggesting that it has the opportunity to spread further with human commerce.
In Costa Rica, this species occurs sporadically in various habitats. At Sirena Station in Corcovado National Park, during extensive field work in the early 1980's, JTL collected the species three times: once under epiphytes in a canopy tree, once in a recent treefall, and once at extrafloral nectaries of a Passiflora. At Fila Cruces, a 1200m elevation site in the southern mountains, JTL found a nest under a stone along a roadside. It was a populous colony, with an acidic smell, an odor more like Formicinae than Dolichoderinae. Workers are also known from the Central Valley, from suburban areas.
Orr, M. R., De Camargo, R. X., and Benson, W. W. 2003. Interactions between ant species increase arrival rates of an ant parasitoid. Anim. Behav. 65:1187-1193.
Orr, M. R., and Seike, S. H. 1998. Parasitoids deter foraging by Argentine ants (Linepithema humile) in their native habitat in Brazil. Oecologia 117: 420-425.
Orr, M. R., Seike, S. H., Benson, W. W., and Dahlsten, D. L. 2001. Host specificity of Psuedacteon (Diptera: Phoridae) Parasitoids that attack Linepithema (Hymenoptera: Formicidae) in South America. Environ. Entomol. 30:742-747.
Wheeler, W. M. 1942. Studies of Neotropical ant-plants and their ants. Bull. Mus. Comp. Zool. 90:1-262.
Wild, A. L. 2007. Taxonomic Revision of the Ant Genus Linepithema (Hymenoptera: Formicidae). University of California Press, Berkeley, CA, USA.
Found most commonly in these habitats: 5 times found in Port of entry, 4 times found in mature wet forest, 3 times found in montane wet forest, 3 times found in vienna sausage, 1 times found in wet forest, 2 times found in lowland rainforest, 2 times found in tropical rainforest, 1 times found in landscaped area in city, 1 times found in lowland forest, 1 times found in wet mountain, ...
Collected most commonly using these methods or in the following microhabitats: 4 times search, 6 times miniWinkler, 3 times surface bait trap, 1 times baiting, 2 times pan trap, 1 times 30cm underground tuna bait, 1 times malaise trap dense woodland, 1 times phorids attack
Elevations: collected from 10 - 2810 meters, 836 meters average