Mycetomoellerius cirratus

Kempf’s notebooks entries #1500 and #1992 say only “ninho no solo” (nests in soil), a common feature for Trachymyrmex.

Identification
A member of the Iheringi species group. Mayhe-Nunes and Brandão (2005) - The recognition of this species is evident by the thick and strongly curved hairs scattered on many parts of the body, subquadrated frontal lobes, and transversely rounded lobes of the antennal scapes. Also the presence of hairs in the mesopleura distinguishes T. cirratus from Mycetomoellerius holmgreni, Mycetomoellerius pruinosus and Mycetomoellerius tucumanus.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  cirratus. Trachymyrmex cirratus Mayhé-Nunes & Brandão, 2005: 275, figs. 9-12 (w.) BRAZIL.
 * Combination in Mycetomoellerius: Solomon et al., 2019: 948.

Worker
TL 3.2-3.4; HL 0 .97-1.00; I-IW 0.91-0.92; IFW 0.58-0.60; ScL 0 .69-0.81; TrL 1.17-1.32; HtL 1.01-1.07. Reddish-brown with a darker spot on the head front. Integument fine and indistinctly shagreened, opaque. Body clothed With thick strongly curved short hairs, and slender and longer hairs, oblique to decumbent on appendages, clypeus, occiput, dorsum of alitrunk, waist and tergum I of gaster.

Head in full face view little longer than broad (CI 93). Mandible smooth and shining except laterally on base where it is inconspicuously striate, and near the masticatory margin, which bears the apical and sub-apical teeth, and 7 regularly developed teeth. Frontal lobe subquadrate, moderately expanded laterad (FLI 64); anterior border concave in the middle; posterior border weakly concave. Frontal carina diverging caudad, fading out a little before the apex of scrobe. Front and vertex without longitudinal rugulae, with minute isolated piligerous tubercles. Posterior third of antennal scrobe vestigially delimited. Supraocular projection inconspicuous. Occiptal corner rounded in full-face view, with many small piligerous tubercles. Occiput notched in the middle. Occipital tooth developed as a stout and tubercle-like projection, rather microtuberculated. Inferior occipital corner with weak carina. Eye weakly convex, no more than 12 facets in a row across the greatest diameter. Antennal scape slightly surpassing the occipital corner, when laid back over head as much as possible; basal lobe transversely enlarged, its lateral projections equally expanded to the sides; anterior surface surmounted by small tubercles.

Alitrunk. Pronotum with an indistinct humeral angle; antero-inferior corner roundly angulated; lateral spine small but stout; median projections as two small microtuberculated spines, similar to lateral ones. Mesonotum with the first pair of projections shorter than pronotal lateral spines; second pair lower, a small and crenulated longitudinal ridge; third pair inconspicuously projected as minute teeth. Mesopleura covered with hairs; blunt teeth-like projection on superior border of katepisternum. Alitrunk constricted dorso-laterally at the deeply impressed metanotal groove. Basal face of propodeum narrow, laterally delimited by a row of small teeth; propodeal spines higher and slender than lateral pronotal spines.

Waist and gaster. Petiole shortly pedunculate, the node proper as long as broad, with two small bifid dorsal teeth; subpetiolar process absent. Postpetiole as long as broad, shallowly excavate above; postero-dorsal border straight; postero-lateral corners without projections. Gaster opaque with minute piligerous tubercles more or less distributed in four irregular longitudinal series in the tergum I.

Type Material
Worker holotype (MZSP; examined) and 22 worker paratypes. BRAZIL, Sao Paulo: Agudos [22° 28' S, 49° 00' W] W. W. Kempf [leg.] several dates: 8.iii.l952 (l paratype); 16.xii.l955 (holotype and 10 paratypes labelled WWK # 1500), 22.xii.1955 (1 paratype), 28.xii.1955 (1 paratype); 15.i.1956 (3 paratypes), 5.xii.l957 paratypes; WWK # 1992).

Etymology
In the drafts we found in MZSP, we noticed that Kempf had chosen the Latin adjective cirrus (curly) to name this species, in reference to its thick, strongly curved short hairs.

References based on Global Ant Biodiversity Informatics

 * Frizzo T. L. M., R. I. Campos, and H. L. Vasconcelos. 2012. Contrasting Effects of Fire on Arboreal and Ground?Dwelling Ant Communities of a Neotropical Savanna. Biotropica 44(2): 254-261.
 * Kempf W. W. 1978. A preliminary zoogeographical analysis of a regional ant fauna in Latin America. 114. Studia Entomologica 20: 43-62.
 * Mayhé-Nunes A. J., and C. R. F. Brandão. 2005. Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 2: the Iheringi group (Hymenoptera: Formicidae). Sociobiology 45(2): 271-305.
 * Solomon S. E., C. Rabeling, J. Sosa-Calvo, C. Lopes, A. Rodrigues, H. L. Vasconcelos, M. Bacci, U. G. Mueller, and T. R. Schultz. 2019. The molecular phylogenetics of Trachymyrmex Forel ants and their fungal cultivars provide insights into the origin and coevolutionary history of ‘higher-attine’ ant agriculture. Systematic Entomology 44: 939–956.
 * Vasconcelos H. L., B. B. Araujo, A. J. Mayhé-Nunes. 2008. Patterns of diversity and abundance of fungus-growing ants (Formicidae: Attini) in areas of the Brazilian Cerrado. Revista Brasileira de Zoologia 25(3): 445-450.