Megalomyrmex mondabora

Boudinot et al. (2013) - This thief ant species is found in a separate chamber from the main fungal galleries within the nest structure of yeast-growing (Adams & Longino 2007), although a single queen was once collected by RMMA with a young Cyphomyrmex rimosus colony in February 2003.

Identification
Boudinot et al. (2013) - Worker uniquely identifiable among Central American Megalomyrmex as follows (1) 8–10 small, subequal teeth subtending apical 2; (2) foraminal carina complete; (3) antennal fossa not encircled by carinulae; (4) scapes relatively long (SI > 115). Queen similarly identifiable as worker, alate. Male recognizable by the following three characters: (1) forewing submarginal cell 1 about eight times as long as width; (2) antenna infuscated at least basally; (3) petiolar and postpetiolar nodes bulbous.

The male of M. mondabora differs from Megalomyrmex mondaboroides by the following: (1) antenna infuscated; (2) occipital carina not visible in full-face view; (3) frontal and occipital carina strong. Differing from all other Central American Megalomyrmex by the following combination of characters: small (ML < 2.0 mm), crossvein 1m-cu and apical abscissa of M absent.

The compound eyes of Megalomyrmex mondabora females (queen, worker) and males are glabrous, whereas workers of Megalomyrmex mondaboroides have very sparse ocular setae and males’ eyes are glabrous.

Distribution
300-1170 m elevation

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

Biology
Longino (2010) - In Costa Rica this species occurs in wet forest habitats, typically in mature rainforest. Collections are from sea level to 800 m elevation on the Atlantic slope of the Cordillera Volcanica Central, Cordillera de Talamanca, and Cordillera de Guanacaste. It is a specialized nest parasite of attines and is found most often in nests of Cyphomyrmex cornutus Kempf (Adams & Longino 2007). It cohabits with C. cornutus in their nests, feeding on both host brood and the host's fungal symbiont.

Adams et al. (2015) found that workers of Cyphomyrmex costatus, the host of Megalomyrmex mondaboroides and Megalomyrmex silvestrii, react to a sting by Megalomyrmex parasites mainly with submissive behavior, playing dead or retreating. Host submission also followed brief antennal contact. The observed behavior of Cyphomyrmex costatus was similar to that of Cyphomyrmex cornutus, host of Megalomyrmex mondabora, suggesting that the alkaloidal venoms with pyrrolidines from M. mondabora, piperidines from M. mondaboroides, and pyrolizidines from M. silvestrii may function similarly as appeasement and repellent allomones against host ants, despite their different chemical structure. With the use of these chemical weapons, Megalomyrmex thief ants are met with little host resistance and easily exploit host colony resources.

Nomenclature

 *  mondabora. Megalomyrmex mondabora Brandão, 1990: 442, fig. 95, 96 (w.) COSTA RICA. Longino, 2010: 47 (q.).

Worker
Mandibles smooth, dental formula 2+ 10; pal­ pal formula 4:3; anterior clypeal border without median denticle; 13 ocular facets at compound eye largest diameter; occipital margin raised; promesonotal suture not impressed dorsally, mesonotum distinguished from pronotum as a swollen area; metanotal groove entirely rugose; katepistemum smooth; propodeum spiracles lat­erally projected in an angle of 45° from the main axis of the body; declivity in general faintly rugose; epipetiolar carina complete; pedunculate petiole with dorsal margin of node, in side view, concave and ventral face with a anteromedian minute denticle originating a non-translucid lon­gitudinal flange; dorsal margin  of petiolar node, in frontal view, round; ventral process of postpe­tiole rugose. Color: mandibles, antennae and legs brown. Anepistemum, katepistemum and propodeum black, with the rest of the body reddish-brown dark and shinny.

Boudinot et al. (2013) - (holotype from Longino 2010): HW 0.74, HL 0.88, SL 1.08, EL 0.23, ML 1.34, SI 123, CI 85. (n=5, plus 10 from Longino 2010): HW 0.74–0.88, HL 0.86–0.96, SL 1.08–1.21, OMD 0.12–0.13, EL 0.26–0.30, ML 1.31–1.50, CI 85–93, SI 121–128, EI 33–35, OMI 40–47.

Queen
Longino (2010) - (n=3): HW 0.939–0.972, HL 0.992–1.012, SL 1.146–1.172, EL 0.327–0.333, ML 1.602–1.645, CI 95–96, SI 114–118.

Palp formula 3,2; general shape, sculpture, and pilosity characters, including mandibular dentition and sculpture, similar to worker; parapsidal lines present, extending from posterior border of mesoscutum to midlength.

Male
Boudinot et al. (2013) - (n=2 from Longino 2010): HW 0.81–0.92, HL 0.75–0.84, SL 0.34–0.40, EL 0.36–0.41, ML 1.38–1.55, CI 45, SI 46–48, EI 44–45.

Head Antenna with 13 antennomeres; antennomere 4 apically kinked; no other antennomeres kinked, nor forming club; scape length subequal to eye length. Antenna infuscated from basad midlength to apex. Palpal formula 4,3. Mandible subfalcate; masticatory margin with 7 teeth; apical tooth more than twice length of subapical tooth; basal teeth somewhat irregular in size and spacing. Dorsal face of mandible smooth and shining, with weak piligerous punctae. Minimum distance between lateral ocellus and compound eye about four lateral ocellus lengths. Compound eye glabrous. Occipital carina visible in full-face view. Mesosoma Mesosoma somewhat attenuate: propodeum elongated. Notauli absent. Parapsidal lines distinct. Foraminal carina present; with concentric carina dorsad. Basitarsi tubular. Pterostigma present, narrow and elongate. Forewing without crossvein 1m-cu; submarginal cell 1 about eight times longer than wide; terminal abscissa of M may be weak, not sclerotized, not joined to Rs, or basally sclerotized and branching from Rs slightly distad 2r-rs. Metasoma Basipetiolar carina arc-shaped. Ventrolateral longitudinal carina of petiole present. Petiolar spiracle in anterior fourth. Posterior margin of petiole with girdling carinae; postpetiole without. Postpetiolar helcium approximately circular. Postpetiolar spiracle placed at about midlength of lateral tergal margin. Sternum of postpetiole bulging at about midlength in profile. Postpetiolar tergum asymmetrically convex; apex posterad midlength. Genitalia Abdominal sternum IX tapering to obtusely triangular apex; apical lobe not sclerotized or produced ventrally. Telomere short, triangular, with acute apex; without medial process; medial face not heavily sclerotized nor arched. Cuspis projecting apicodorsally; apical margin slanting anteroventrally. Digitus narrow to very narrow; apex bluntly rounded; dorsal margin slightly more arched than ventral margin; ventral margin not obscuring posterodorsal angle of cuspis. Valviceps about half as tall as long, subovate; dorsal margin shallowly sloping to apical margin; ventral margin weakly convex; penisvalvar teeth narrow and close-set.

Type Material
Holotype and 2 paratypes from Turialba, Cartago province, at Museum of Comparative Zoology, Harvard,: 1 paratype from Turialba, Cartago province, and 1 paratype from Vi­lhena at Museu de Zoologia da USP.

Etymology
The types of Turialba, collected by W. L. Brown Jr. between 18 and 22 of January, 1973, were found associated with workers of an uniden­tified Apterostigma (Attini). Therefore I choose the name mondabora, meaning robber in Tupi.

References based on Global Ant Biodiversity Informatics

 * Adams, R.M.M. and J.T. Longino. 2007. Nesting biology of the arboreal fungus-growing ant Cyphomyrmex cornutus and behavioral interactions with the social-parasitic ant Megalomyrmex mondabora. Insectes Sociaux 54:136-143
 * Boudinot B. E., T. P. Sumnicht, and R. M. M. Adams. 2013. Central American ants of the genus Megalomyrmex Forel (Hymenoptera: Formicidae): six new species and keys to workers and males. Zootaxa 3732(1): 1-82.
 * Longino J. T. 2010. A taxonomic review of the ant genus Megalomyrmex Forel (Hymenoptera: Formicidae) in Central America. Zootaxa 2720: 35-58
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.
 * Longino J. T., and R. K. Colwell. 2011. Density compensation, species composition, and richness of ants on a neotropical elevational gradient. Ecosphere 2(3): 16pp.
 * Mertl A. L., J. F. A. Traniello, K. Ryder Wilkie, and R. Constantino. 2012. Associations of two ecologically significant social insect taxa in the litter of an amazonian rainforest: is there a relationship between ant and termite species richness? Psyche doi:10.1155/2012/312054
 * Ulyssea M. A., C. R. F. Brandao. 2013. Catalogue of Dacetini and Solenopsidini ant type specimens (Hymenoptera, Formicidae, Myrmicinae) deposited in the Museu de Zoologia da Universidade de Sao Paulo, Brazil. Papies Avulsos de Zoologia 53(14): 187-209.