Megalomyrmex

''Megalomyrmex'' is a genus of ant in the subfamily Myrmicinae. The genus is known only from the Neotropics, where some of the species are specialized parasites or predators of Attini.

Description

It is difficult to characterize morphologically. Bolton (2003) placed it in the tribe Solenopsidini, but with multiple exceptions to the diagnostic characters for the tribe. The tribal characters include a bicarinate clypeus and a median clypeal seta. Most ''Megalomyrmex'' species have a smoothly convex clypeus with no trace of the bicarinate condition, and most have abundant clypeal setae with no distinct or differentiated median seta. In Bolton's (1994) key to genera, ''Megalomyrmex'' keys in multiple places because of variability in mandibular dentition. Nevertheless, the genus has a distinctive habitus: the antenna is 12-segmented with a 3-segmented club; the general integument is smooth and shiny without coarse sculpture or dull areas; the promesonotum is evenly arched, without promesonotal groove; the propodeum is usually smoothly curved between dorsal and posterior faces, at most with blunt, broad-based tubercles, and never with spines; and the hind tibial spur is simple. In short, the workers look like a '' Solenopsis'' with ''Pheidole'' antennae. The mandibular dentition varies from a simple set of 5 similar teeth on the masticatory margin, gradually diminishing in size basally, to a condition with 2 large apical teeth followed by up to 12 small denticles.

Some species have unusual alkaloids. The hypothesis that alkaloids act at a distance converges with what is known for the genera '' Solenopsis'', ''Monomorium'' and ''Megalomyrmex'' when workers release volatile venom alkaloids by waving their stingers (i.e., gaster flagging) during interspecific encounters causing their enemies to flee.

It is close to ''Monomorium'' and should possibly be included in the latter.

Distribution and habitat

Although widespread in the Neotropics, from southern Mexico to northern Argentina, ''Megalomyrmex'' species are never abundant. They occur in low to middle elevation wet to dry forest habitats. Some species are free-living with large diffuse nests in the soil (e.g. '' Megalomyrmex modestus'') or small nests in dead wood (e.g. '' Megalomyrmex drifti''). Others are specialized social parasites or predators of Attini (e.g. '' Megalomyrmex adamsae'', '' Megalomyrmex mondabora'', '' Megalomyrmex symmetochus'', '' Megalomyrmex wettereri'').

Species

*'' Megalomyrmex acauna'' Brandão, 1990
*'' Megalomyrmex adamsae'' Longino, 2010
*'' Megalomyrmex ayri'' Brandão, 1990
*'' Megalomyrmex balzani'' Emery, 1894
*'' Megalomyrmex bidentatus'' Fernández & Baena, 1997
*'' Megalomyrmex bituberculatus'' (Fabricius, 1798)
*'' Megalomyrmex brandaoi'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex caete'' Brandão, 1990
*'' Megalomyrmex cuatiara'' Brandão, 1990
*'' Megalomyrmex cupecuara'' Brandão, 1990
*'' Megalomyrmex cyendyra'' Brandão, 1990
*'' Megalomyrmex drifti'' Kempf, 1961
*'' Megalomyrmex emeryi'' Forel, 1904
*'' Megalomyrmex foreli'' Emery, 1890
*'' Megalomyrmex fungiraptor'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex glaesarius'' Kempf, 1970
*'' Megalomyrmex gnomus'' Kempf, 1970
*'' Megalomyrmex goeldii'' Forel, 1912
*'' Megalomyrmex iheringi'' Forel, 1911
*'' Megalomyrmex incisus'' Smith, 1947
*'' Megalomyrmex leoninus'' Forel, 1885
*'' Megalomyrmex longinoi'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex megadrifti'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex milenae'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex miri'' Brandão, 1990
*'' Megalomyrmex modestus'' Emery, 1896
*'' Megalomyrmex mondabora'' Brandão, 1990
*'' Megalomyrmex mondaboroides'' Longino, 2010
*'' Megalomyrmex myops'' Santschi, 1925
*'' Megalomyrmex nocarina'' Longino, 2010
*'' Megalomyrmex osadrifti'' Boudinot, Sumnicht & Adams, 2013
*'' Megalomyrmex pacova'' Brandão, 1990
*'' Megalomyrmex piriana'' Brandão, 1990
*'' Megalomyrmex poatan'' Brandão, 1990
*'' Megalomyrmex pusillus'' Forel, 1912
*'' Megalomyrmex reina'' Longino, 2010
*'' Megalomyrmex silvestrii'' Wheeler, 1909
*'' Megalomyrmex staudingeri'' Emery, 1890
*'' Megalomyrmex symmetochus'' Wheeler, 1925
*'' Megalomyrmex tasyba'' Brandão, 1990
*'' Megalomyrmex timbira'' Brandão, 1990
*'' Megalomyrmex wallacei'' Mann, 1916
*'' Megalomyrmex wettereri'' Brandão, 2003
*'' Megalomyrmex weyrauchi'' Kempf, 1970

References

*Bolton, B. (1994) Identification Guide to the Ant Genera of the World. Harvard University Press, Cambridge, MA, London, 222 pp.
*Bolton, B. (2003) Synopsis and classification of Formicidae. ''Memoirs of the American Entomological Institute'' 71: 1–370
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External links

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{{Taxonbar, from=Q6808513

Myrmicinae
Ant genera
Taxonomy articles created by Polbot
Taxa named by Auguste Forel