Megalomyrmex pusillus

Nothing is known about the biology of .

Identification
Brandão (1990) - Forel (1912) observed a wide deep brown transversal band at the first gaster segment, contrasting with the light-yellow body. This condition is not constant for most samples, but it is present in the three available dealated females. I noticed intraspecific variation among workers in terms of color, presence of median seta at the clypeal set, degree of development of the anteromedian clypeal denticle and propodeum shape. The sample from Alto da Serra, SP, Brasil (types and non-types) have extreme values for all measured characters, as already noticed by Borgmeier (1939).

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, Mexico.

Biology
Brandão (2003) - Of this rather rarely collected, although very distinctive species, I received from a worker collected in Poços de Caldas, Minas Gerais state, Brazil (21°48’S, 46°34’W), in October 28, 1991, by A.M.D. Aguiar. This is the first record of this species in Minas Gerais.

Castes
Known only from the worker caste.

Nomenclature

 *  pusillus. Megalomyrmex pusillus Forel, 1912g: 15 (w.) BRAZIL. Brandão, 1990: 453 (q.).

Worker
Brandão (1990) - Smooth mandibles with dental formula (1-2) + 4; anterior border of clypeus in general round with median denticle; frontal suture not impressed; occipital margin not raised: promesonotal suture when present faintly impressed at dorsum; dorsal face and declivity of propodeum meeting in lateral acute tubercles divergent at apex and laterally compressed: declivity smooth; epipetiolar carina not complete dorsally; ventral face of postpetiole with anterior denticle; postpetiole ventral face without process.

Pilosity: long erect or suberect hairs (exceeding compound eyes diameter) at body dorsum and smaller subdecumbert hairs at clypeus, antennae and legs.

Color: bright light yellow.

Queen
Brandão (1990) - Differs from conspecific workers in the following characters: triangular head in frontal view with areas of striation at the antenna! sockets and distal portion of lateral area of clypeus. Ocelli equally developed. Median propodeal depression deeper than in workers. Postpetiolar node distinctly broader than petiolar node.

Type Material
Brandão (1990) - Alto da Serra, SP, Brasil (23°47'S, 46°19'W). Lectotype designation: Lectotype and 1 paralectotype at the Museum de la Ville de Geneve; 1 paralectotype at Naturhistorisches Museum. Basel.

References based on Global Ant Biodiversity Informatics

 * Borgmeier T. 1939. Nova contribuição para o conhecimento das formigas neotropicas (Hym. Formicidae). Revista de Entomologia (Rio de Janeiro) 10: 403-428.
 * Brandão C. R. F. 1990. Systematic revision of the Neotropical ant genus Megalomyrmex Forel (Hymenoptera: Formicidae: Myrmicinae), with the description of thirteen new species. Arquivos de Zoologia (São Paulo) 31: 411-481
 * Brandão C. R. F. 2003. Further revisionary studies on the ant genus Megalomyrmex Forel (Hymenoptera: Formicidae). Papeis Avulsos de Zoologia (São Paulo) 43: 145-159
 * Favretto M. A., E. Bortolon dos Santos, and C. J. Geuster. 2013. Entomofauna from West of Santa Catarina State, South of Brazil. EntomoBrasilis 6 (1): 42-63.
 * Fleck M. D., E. Bisognin Cantarelli, and F. Granzotto. 2015. Register of new species of ants (Hymenoptera: Formicidae) in Rio Grande do Sul state. Ciencia Florestal, Santa Maria 25(2): 491-499.
 * Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
 * Kempf W. W. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Rosa da Silva R. 1999. Formigas (Hymenoptera: Formicidae) do oeste de Santa Catarina: historico das coletas e lista atualizada das especies do Estado de Santa Catarina. Biotemas 12(2): 75-100.
 * Silva R.R., and C. R. F. Brandao. 2014. Ecosystem-Wide Morphological Structure of Leaf-Litter Ant Communities along a Tropical Latitudinal Gradient. PLoSONE 9(3): e93049. doi:10.1371/journal.pone.0093049
 * Suguituru S. S., M. Santina de Castro Morini, R. M. Feitosa, and R. Rosa da Silva. 2015. Formigas do Alto Tiete. Canal 6 Editora 458 pages
 * Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-611.