Cephalotes pileini

Identification
A member of the pinelii clade differing from its outgroup species, Cephalotes nilpiei, and from its ingroup species Cephalotes pinelii, in the worker, by the head longer than the pronotal width, and, from the soldier of nilpiei and pinelii, by the floor of the disc less concave and by the absence of propodeal teeth. All the Argentinean workers from La Carlota and described here as pileini differ from those of pinelii (known only from Paraguay and Brazil) by the head and gaster much longer, by the membranaceous expansions of the mesosoma narrower, and by the foveae much denser and irregular. The soldiers and gynes of pileini differ from those of pinelii by the vertexal groove shallower, by the border of the frontal carinae less crenulate, by the hairs on the frontal carinae sparser, by the foveae less impressed and by the pronotal crest very reduced in the soldier and absent in the gyne. (de Andrade and Baroni Urbani 1999)

Distribution based on Regional Taxon Lists
Neotropical Region: Argentina.

Nomenclature

 *  pileini. Cephalotes pileini De Andrade, in De Andrade & Baroni Urbani, 1999: 385, figs. 171, 172 (s.w.q.) ARGENTINA.

Worker
Head subquadrate with convex frons. Frontal carinae covering the mandibles proximally and slightly upturned above the eyes Vertexal angles round, with a thin, membranaceous margin converging and narrowing before the middle of the vertexal border. Mandibles with thick lateral carina.

Mesosoma gently convex. Scapular angles absent or not visible in dorsal view. Anterior border of the pronotum convex in dorsal view; pronotal sides with a membranaceous expansion anteriorly obtuse and narrowing posteriorly. Promesonotal suture, in dorsal view, superficially impressed on the sides only. Mesonotum with a pair of pointed or obtuse, membranaceous teeth. Propodeal suture impressed. Declivous face of the propodeum gently sloping backwards. Basal and declivous propodeal faces with a membranaceous lateral expansion originating from the propodeal suture.

Anterior face of the petiole medially concave; dorsal face gently convex. Sides of the petiole with a wing-shaped, membranaceous expansion with round tip and directed laterally. Postpetiole convex dorsally; postpetiolar sides also with a wing-shaped, membranaceous expansion with round tip.

Gaster oval and elongate. First gastral tergite anterolaterally with a broad membranaceous expansion.

Legs. Mid and hind femora dorsally angulate and with a carina on the distal part of their dorsum. Mid and hind basitarsi compressed at the base.

Sculpture. Head dorsum minutely reticulate, with dense foveae diminishing in size anteriorly. Ventral face of the head reticulate and with superficial, dense foveae forming longitudinal rugosities anteriorly. Mesosoma and pedicel reticulate, with irregular, dense foveae forming longitudinal, irregular rugosities, the foveae smaller on the propodeum and on the pedicel. Gaster and legs deeply reticulate. First gastral tergite with thin, longitudinal rugosities on the anterior third, the rugosities becoming thinner and more superficial posteriorly. Membranaceous expansions of mesosoma, pedicel and gaster reticulate, the latter with few, thin, longitudinal rugosities anteriorly.

Pilosity. Each fovea with an appressed hair; similar hairs but not originating from the foveae and slightly thinner 6n the membranaceous expansions, on the gaster and on the legs. Posterior border of the gastral segments with rare, erect, clubbed hairs.

Colour. Dark brown with lighter legs. Frontal carinae orange and semi-transparent. Membranaceous expansions of the body yellowish and semi-transparent. First gastral tergite anterolaterally with an orange, long, thin strip directed posteriorly. Some specimens with the head darker than the rest of the body.

Measurements (in mm) and indices: TL 3.55-4.44; HL 0.86-0.96; HW 0.93-1.06; EL 0.24-0.25; PW 0.79-0.89; PeW 0.54-0.61; PpW 0.53-0.63; HBaL 0.25; HBaW 0.10; CI 108.1-110.4; PI 117.7-117.8; PPeI 146.3-147.5; PPpI 142.8-149.0; HBal 40.0.

Soldier
Head disc subround, with differentiated border and raised more on the sides than posteriorly. Sides of the disc not covering completely the eyes and broadening anteriorly. Floor of the disc concave and with a small tumulus in the middle. Vertex with a superficial depression.

Vertexal angles round, completely separate from the disc and with superficially crenulate border. Mandibles laterally carinate and laterally hidden by the frontal carinae.

Mesosoma. Anterior pronotal border gently convex. Humeral angles with a narrow, obtuse, lateral, membranaceous expansion converging posteriorly up to the middle of the pronotum where it continues into the poorly marked pronotal carina. Posterior half of the pronotal sides strongly converging posteriorly. Pronotal suture in dorsal view impressed on the sides. Promesonotal suture deeply impressed. Mesonotal sides with two pairs of teeth, the anterior pair broad, and with truncate tips, the posterior pair small, thin and pointed. Propodeum with differentiate basal and declivous faces; sides of the basal face convex, with the posterior half bearing a narrow membranaceous expansion extending and broadening up to the end of the declivous face.

Pedicel as in the worker but with the expansions less broad.

Legs as in the worker but with the dorsal carina less impressed.

Gaster oval, with a margin not reaching the stigma posteriorly.

Sculpture. Head dorsum, mesosoma and pedicel reticulate-punctate and covered by dense foveae, smaller and shallower on the border of the disc and on the clypeus, on the propodeum and on the pedicel. Ventral face of the head reticulate and with irregular, superficial foveae and irregular rugosities. Declivous face of the propodeum reticulate and with thin, longitudinal rugae. Gaster and legs strongly reticulate and with superficial, minute foveae. First gastral tergite with thin, longitudinal rugosities on the anterior third, less impressed and irregular posteriorly.

Pilosity. Each fovea with an appressed hair. Legs and gaster with appressed hairs thinner and shorter than those originating from the foveae. Border of the disc over the eyes, and posterior border of the gastral segments with rare clubbed hairs. The sternites bear, in addition a few long, thin, slightly pointed hairs.

Colour. Dark brown with the sides of the mesonotum, of the pedicel and of the first gastral tergite with a lighter strip.

Measurements (in mm) and indices: TL 5.14-5.40; HL 1.20-1.26; HW 1.32-1.36; EL 0.25-0.28; PW 1.28-1.32; PeW 0.64-0.65; PpW 0.67-0.69; HBaL 0.27; HBaW 0.12; CI 107.9-110.0; PI 103.0-103.1; PPeI 200.0-203.1; PPpI 185.5-197.0; HBal 44.4.

Queen
Head disc present. Head dorsum gently convex posteriorly and with concave anterolateral sides. Frontal carinae superficially crenulate, expanded anteriorly, converging posteriorly and connected by a convex carina on the vertex. Vertex between the pair ocelli with a superficial depression. Vertexal angles round and with marked margin. Eyes visible in full dorsal view. Ocelli remote from the posterior border of the head disc. Anterior clypeal border deeply concave. Mandibles with a lateral carina and partially hidden by the frontal cannae.

Mesosoma. Anterior pronotal border gently convex. Humeral angles obtuse. Pronotal sides straight. Pronotal carina absent. Promesonotal suture impressed. Lower mesopleurae with a denticle. Mesonotum and scutellum flat. Propodeum with differentiate basal and declivous faces; sides of the basal face convex; declivous face converging posteriorly and with a narrow membranaceous border on the posterior half.

Petiolar sides convex and with marked margin. Postpetiolar sides with a round lobe directed anteriorly.

Gaster with a pair of broad, anteriorly protruding lobes.

Sculpture. Head dorsum reticulate and with dense foveae diminishing in size anteriorly and less impressed in the middle" of the frontal carinae. Mesosoma and pedicel with the same type of sculpture as on the anterior part of the head dorsum, but with sparser foveae on the middle of the mesonotum. Declivous face of the propodeum, gaster and legs as in the soldier.

Pilosity. As in the soldier.

Colour. Brown, floor of the disc darker. Frontal carinae orange and semi-transparent. Sides of the pronotum and of the propodeum yellowish. First gastral tergite with two pairs of yellowish spots, thc first pair anterolateral and the second one before the posterior border.

Measurements (in mm) and indices: TL 6.72-7.00; HL 1.26-1.32; HW 1.26-1.28; EL 0.31-0.32; PW 1.24; PeW 0.58; PpW 0.69-0.72; HBaL 0.40; HBaW 0.14; CI 97.0-100.0; PI 101.6-103.2; PPeI 213.8; PPpI 172.2-179.7; HBaI 35.0.

Type Material
Holotype: soldier, Argentina, Cordoba, La Carlota, Silvestri.

Paratypes: four workers and one gyne MCZ, one worker and one gyne, one worker and one soldier , three workers and one soldier , same data as the holotype.

Etymology
Pileini is an anagram of pinelii, the name of the species with which this species had been previously confused.