Mycetomoellerius dichrous

Walter Kempf and his student Jorge Diniz discovered numerous nests of this species in recently burned cerrado.

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

Castes
Known only from the worker caste.

Nomenclature

 *  dichrous. Trachymyrmex dichrous Kempf, 1967a: 126, figs. 7-9 (w.) BRAZIL.

Worker
Mayhé-Nunes & Brandão (2002) - TL 4.5-5.1; HL 0.99-1.07; HW 1.03-1.11; IFW 0.51-0.57; ScL 0.93-1.07; TrL 1.51-1.70; WL mm; Hfl 1.49-1.70. Strikingly bicolored, head capsule deep brown, body and appendages medium brown or ferruginous. Integument finely but indistinctly shagreened, opaque. Long, dense, mostly curved or inclined hairs on head, alitrunk, and pedicel; same hairs but denser and less curved and more uniformly inclined on gaster, scapes and legs. Alitrunk hairs not arising from prominent tubercles which are lacking. Dense and much shorter pubescence of lighter color, inclined or appressed on head, pedicel, gaster and appendages. erect or suberect on thorax, never masking the integument.

Head. Mandibles smooth and shining except laterally on base where they are finely longitudinally striate; masticatory margin with apical tooth and approximately 8 teeth. slightly smaller towards the base. Frontal lobe triangular, little expanded laterad, interfrontal width scarcely or not at all surpassing one half of head width across the eyes. Frontal carinae diverging caudad, fading out at posterior fourth of head. Front and vertex inconspicuously tuberculate. Preocular carinae slightly curving mesad above eye but not intersecting the antennal scrobe, fading out shortly behind eyes. Posterior half of antennal scrobe indistinct, the apex not projecting in a tuberous fashion on occiput; supraocular tumulus vestigial. Occipital corners rounded and edentate. Occipital tooth absent. Occiput in full-face view distinctly notched in the middle. Vertex lacking paired carinae. Inferior occipital corner indistinctly marginate and rounded. Eyes moderately convex, with about 13 facets across the greatest diameter. Antennal scapes as long, or nearly as long, as head capsule, without prominent spicules, surpassing the occipital corner when laid back over the head as much as possible by one fifth of its length. All funicular segments distinctly longer than broad.

Alitrunk. Prominent piligerous tubercles lacking. Pronotum with indistinct humeral angles, its antero-inferior corners rounded and toothless. The lateral spines very low and tubercular. Mesonotum with a pair of high anterior conical spines, facing obliquely laterad, followed by two pairs of very low and little distinct denticulate tubercles, the posterior pair almost obsolete. AI trunk shallowly impressed at metanonotal groove. Basal face of propodeum narrow, lateral borders indistinctly marginate, bearing a few piligerous tubercles. Propodeal spines very short and inconspicuous. Hind femora about as long as alitrunk.

Waist and gaster. Petiole pedunculate, the node proper longer than broad, the dorsal armature obsolete; anterior ventral process developed as a small blunt spine. Postpetiole not much broader than long, flattened above, the postero-dorsal border broadly excised between the non-tubercular corners. Gaster opaque; tergum I with dense, minute and evenly distributed piligerous tubercles; vestigially marginate on sides in the anterior half.

Type Material
Mayhé-Nunes & Brandão (2002) - Holotype and 6 paratypes from type locality, one paratype from Brasil: Mato Grosso, Chapada dos Guimaraes, and one paratype from Brasil: Sao Paulo, Agudos at (examined).