Dolichoderus validus

Identification
Color black with abundant yellow pubescence; scapes and mesosomal dorsum with abundant erect setae; dorsal and posterior faces of propodeum separated by a well-defined transverse flange; petiolar summit not transversely truncate, lateral margin continuing and tapering into spine; vertex margin strongly concave. Similar to the species Dolichoderus bispinosus and Dolichoderus curvilobus.

Distribution based on Regional Taxon Lists
Neotropical Region: Costa Rica, Ecuador, Panama.

Biology
MacKay (1993): Swain (1977) reported extensively on the biology of this species. Nests are completely different than those of Dolichoderus bispinosus. They are arboreal, 1.5 - 6 meters above the surface, constructed of coarse plant fibers (3 cm long) woven together like burlap. These ants apparently never nest in termite nests. They build shelters to enclose membracids. This species is probably monogynous; a nest contained 2,200 workers. They are aggressive when defending the nest. Nectar is the principal food source. They tend membracids and coccids, and visit extrafloral nectaries of plants including Inga edulis. They also collect bird droppings, insect fragments, seeds and unidentified material. They have a crepuscular foraging rhythm. Flights occur at dawn.

At La Selva Biological Station Phil DeVries found a large carton nest suspended from the thin branches of Rinorea (Violac.) tree. I collected the entire nest into a plastic bag, which was no easy task because these ants are incredibly aggressive. I placed the nest in a freezer for a day and then dissected it. In addition to workers and brood there were many males and alate queens. I never found the colony queen but the dissection was cursory enough that she could have been lost among the debris. The center of the nest contained what appeared to be an old euglossine bee tube. I encountered many tiny white cocoons in the nest, scattered and attached to the carton. One contained an adult beetle, but I have not succeeded in identifying it. I saw no other inquilines. I estimated the colony size to be 11800 workers, based on the wet weight of the entire sample, and weights of 10 subsamples for which number of ants was counted. (Jack Longino)

Nomenclature

 *  validus. Monacis validus Kempf, 1959b: 244, pl. 1, fig. 5; pl. 2, fig. 9; pl. 3, fig. 7; pl. 5, fig. 4 (w.q.) COSTA RICA. Combination in Dolichoderus: Shattuck, 1992c: 77. See also: Mackay, 1993b: 104.

References based on Global Ant Biodiversity Informatics

 * Basset Y., L. Cizek, P. Cuenoud, R. K. Didham, F. Guilhaumon, O. Missa, V. Novotny, F. Odegaards, T. Roslin, J. Schmidl et al. 2012. Arthropod diversity in a tropical forest. Science 338(6113): 1481-1484.
 * Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
 * Kempf W. W. 1959. A revision of the Neotropical ant genus Monacis Roger (Hymenoptera: Formicidae). Studia Entomologica (n.s.)2: 225-270.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Levings S. C. 1983. Seasonal, annual, and among-site variation in the ground ant community of a deciduous tropical forest: some causes of patchy species distributions. Ecological Monographs 53(4): 435-455.
 * Longino J. T., J. Coddington, and R. K. Colwell. 2002. The ant fauna of a tropical rain forest: estimating species richness three different ways. Ecology 83: 689-702.
 * Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/
 * Mackay, W.P. 1993. A review of the New World ants of the genus Dolichoderus (Hymenoptera: Formicidae). Sociobiology 22(1):1-148
 * Ribas C. R., and J. H. Shoereder. 2007. Ant communities, environmental characteristics and their implications for conservation in the Brazilian Pantanal. Biodivers. Conserv. 16: 1511-1520.
 * Shattuck S. O. 1994. Taxonomic catalog of the ant subfamilies Aneuretinae and Dolichoderinae (Hymenoptera: Formicidae). University of California Publications in Entomology 112: i-xix, 1-241.
 * Ulyssea M. A., L. Pires do Prado, C. R. F. Brandao. 2017. Catalogue of the Dolichoderinae, Formicinae and Martialinae (Hymenoptera: Formicidae) types deposited at the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulsos de Zoologia 57(23): 295-311.
 * Ulyssea M. A., L. Pires do Prado, and C. R. F. Brandao. 2017. Catalogue of the Dolichoderinae, Formicinae and Martialinae (Hymenoptera: Formicidae) types deposited at the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papeis Avulos de Zoologia 57(23): 295-311.