Cyatta

A monotypic genus closely allied with the attine genus Kalathomyrmex. The single known species is a fungus growing ant.

Identification
The genus Cyatta shares with other genera belonging to the tribe Attini: (i) the presence of a thick unpaired median seta arising from the clypeal apron (considered a synapomorphy for the tribe by Brandão & Mayhé-Nunes; but, along with the clypeal apron, presumed secondarily lost in Kalathomyrmex); (ii) 11 antennal segments in the worker and gyne, 13 in the male (the latter secondarily reduced in some Cyphomyrmex, Mycetagroicus, Sericomyrmex, Trachymyrmex, and social parasites); (iii) palpal formula 4,2 (plesiomorphic for the Attini, secondarily reduced in Apterostigma and some social parasites). Larvae of Cyatta share with the larvae of other attine genera the: (iv) thoracic-abdominal articulation apparently absent; (v) thoracic intersegmental constrictions superficial; (vi) deep lateral depressions associated with abdominal spiracles absent; (vii) short, narrow labrum; and (viii) fleshy, subconical mandibles. Behaviorally, Cyatta shares with other Attini the cultivation of fungi for food.

The genus Cyatta shares with other members of the neoattine clade: (i) the antennal scape of the male long, longer than the sum of the length of antennal funicular segments I–III; (ii) the first funicular segment (pedicel) of the antenna of the male longer than second funicular segment; (iii) the petiole in workers somewhat sessile; (iv) the lack of hypostomal teeth in workers and gynes; and (v) the maxillary palp of the larva widely removed laterad from the galea.

Cyatta shares with its sister genus, Kalathomyrmex, (i) the lack of a tubercle or spine on the inferior lateral margin of the pronotum, a symplesiomorphy shared with the paleoattine clade; (ii) the clypeus with a pair of lateral transverse carinae, each extending from the frontal lobe to the mandibular insertion and each medially developed into a lamella perpendicular to the clypeal face, thus forming a wall that divides the clypeus laterally into anterior and posterior areas; and (iii) the mandibles of the male with three teeth, of which the apical and preapical teeth are the largest and have a multidentate (sawlike) margin.

Cyatta differs from its sister genus Kalathomyrmex, however, by (i) having, on the forewing of the male (forewing of gyne unknown), a closed marginal cell (open in the forewings of both the male and gyne of Kalathomyrmex [Klingenberg and Brandão, therein as radial cell]); (ii) the mesoscutum of the male with strongly impressed notauli (absent in the male of Kalathomyrmex); (iii) the pronotum of the male with lateral pronotal tubercles present, pyramidal (the pronotum in the male of Kalathomyrmex lacks any tubercles); and (iv) the psammophore absent in the worker, the gyne, and the male.

Most notably, Cyatta differs from all other attine genera and species by the following autapomorphies: (i) mandible of the worker and gyne with four teeth; (ii) in ventral view, metapleura of the worker and gyne with two piniform processes between the mid and hind coxae, apparently absent in the male; (iii) apical margin of the pygidium medially emarginate, V-shaped; and (iv) forewing of the male with a closed discal cell.

Biology
See Cyatta abscondita.

Nomenclature

 *  CYATTA [Myrmicinae: Attini]
 * Cyatta Sosa-Calvo, Schultz, Brandão et al., 2013: 4. Type-species: Cyatta abscondita, by original designation.

Worker
Small, monomorphic attine ant, total length (TL)= 2.29–2.56; Weber’s length (WL)= 0.58–0.65. Color pale yellow to light brown. Body densely reticulate and covered with minute simple appressed hairs, more abundant on dorsum of head, waist segments, and gaster than on mesosoma. Palp formula 4,2. Anterior margin of clypeus produced into a convex, almost triangular, smooth, shining flange, i.e., "clypeal apron," with long unpaired median seta that originates closer to its posterior margin. Psammophore absent. Masticatory margin of mandibles 4-toothed. Antennal scrobes and preocular carinae absent. Antennae 11-segmented. Frontal lobes reduced, barely covering antennal insertions and diverging anteriorly. Frontal area subtriangular, distinct. In full-face view, posterior cephalic margin inflated laterally and strongly notched medially. Tubercles on mesosomal dorsum short, attenuate, and blunt. Metapleura with two spiniform processes between mid and hind coxae. Propodeum armed with a pair of short triangular spines. Node of petiole high, well-developed. Gaster lacking carinae or tubercles. In lateral view, pygidium rounded, laterally overlapping and concealing the hypopygium; in ventral view, pygidium posteromedially emarginate (i.e., V–shaped), the triangular hypopygium fitting within the emargination of the pygidium.

Queen
Preocular carina absent. Mandible 4-toothed, apical tooth nearly twice as long as preapical tooth. Parapsidal lines inconspicuous.

Male
Mandibles broadly triangular with apical and subapical teeth present. Anterior margin of clypeus (clypeal apron) convex, projecting over mandibles, and with a long median seta. Discal cell present in forewing.

Etymology
Cyatta is a neologism constructed in part from the Brazilian Tupi language word Cy, meaning "sister," referring to its status, along with the genus Kalathomyrmex, as the sister clade to the remaining genera of the informal clade Neoattini, to which the genus Atta, the most conspicuous member of the Neoattini, belongs.