Cephalotes pallidus

Identification
A member of the pallens clade differing from its sister species, Cephalotes pallidoides, by the following characters: in the worker, soldier and gyne, body sculpture deeper, femora less inflate, and HBaI ≤ 48, and, in the soldier and gyne only, floor of the disc with a protruding swelling and margin of the disc more densely crenulate. The soldier and the gyne of pallidus are different from all the other species of the pallens clade by the deep, broad, contiguous, irregular foveae on the head disc.

Key to Cephalotes Workers

Distribution
Guyana, Suriname, Brazil, Peru and Bolivia

Distribution based on Regional Taxon Lists
Neotropical Region: Bolivia, Brazil, Ecuador, Guyana, Peru, Suriname.

Nomenclature

 *  pallidus. Cephalotes pallidus De Andrade, in De Andrade & Baroni Urbani, 1999: 473, figs. 218-221, 390 (s.w.q.m.) GUYANA.

Worker
Similar to the other species of the group from which it differs for one or more of the following characters. Head broader than long. Membranaceous expansions of the vertexal angles variably developed and strongly crenulate. Frontal carinae crenulate.

Mesosoma. Pronotum with a pair of developed membranaceous expansions. Mesonotum with a pair of triangular or truncate teeth. Propodeum with a pair of broad, gently convex, crenulate, membranaceous expansions, the crenulations variably impressed according to the specimen.

Anterior face of the petiole slightly concave. Petiolar sides with a pair of pointed spines more than 1.3 longer than the maximum petiolar length. Postpetiolar sides with a pair of pointed spines shorter than those of the petiole and directed forwards.

Gaster oval and with a pair of protruding membranaceous expansions reaching the stigma posteriorly and continuing as a thin margin backwards up to the posterior border.

Mid and hind femora gently angulate; mid femora with a carina; hind femora with a crest. Mid and hind basitarsi flat, with the proximal part much broader than the distal one.

Sculpture. Head dorsum minutely punctate, with dense, deep, irregular foveae diminishing in size anteriorly, sparser or rare and more superficial on the frontal carinae. Frontal carinae with strong, oblique rugosities. Ventral part of the head strongly reticulate. Mesosoma minutely punctate and with dense foveae as on the head dorsum, the foveae smaller on the mesonotum and on the propodeum. Propodeum with additional, irregular, longitudinal rugosities. Pleurae usually strongly reticulate, only with superficial, irregular, sparse foveae and few, thin rugosities in some specimens. Pedicel punctate and with small, dense, irregular foveae. Anterior third and sides of the first gastral tergite strongly reticulate and with superficial, irregular foveae; the foveae diminishing in size posteriorly and separate by thin, irregular, longitudinal rugosities only on the anterior third. First gastral sternite strongly reticulate and with irregular, thin rugosities. Remaining gastral tergites and sternites reticulate. Legs strongly reticulate and with small, irregular foveae, dense on the outer face of the tibiae.

Pilosity. Each fovea with a decumbent hair. Sides of the frontal carinae, of the vertexal angles, first gastral tergite, posterior borders of the gastral segments and legs with short, clubbed hairs, denser on the sides of the frontal carinae. Gastral sternites with two additional types of erect, pointed hairs: (1) sparse and short and, (2) rare, long and thin on the second sternite. Parts of the gaster and legs without foveae simply with appressed, thin hairs.

Colour. Brown to black with the membranaceous expansions of the body lighter.

Measurements (in mm) and indices: TL 3.97-4.49; HL 0.96-1.02; HW 1.04-1.16; EL 0.25-0.26; PW 0.90-1.00; PeW 0.63-0.72; PpW 0.52-0.61; HBaL 0.23-0.28; HBaW 0.11-0.12; CI 108.3-114.0; PI 114.0-122.1; PPeI 138.9-142.8; PPpI 161.0-173.1; HBaI 42.3-47.8.

Soldier
Head longer than broad. Sides of the disc raised and with strongly crenulate margin. Floor of the disc with a convex median tumulus pointed apically in large specimens. Vertex posteriorly variably depressed. Vertexal angles with crenulate margin.

Mesosoma. Humeral angles with a pair of obtuse, semi-membranaceous teeth. Pronotum gently converging posteriorly. Pronotal carina marked, crenulate and shortly interrupted medially, continuous and simply lower in Lhe middle in some specimens. Mesonotum with a pair of broad, round or truncate teeth. Sides of the basal face of the propodeum with one-two pairs of irregular swellings followed by a pair of stout teeth curved upwards and forwards. Declivous face of the propodeum narrowing posteriorly narrowly marginate in small specimens.

Anterior face of the petiole medially concave. Petiolar and postpetiolar sides with spines shorter and less pointed than in the worker.

Gaster oval with a pair of protruding lobes.

Mid and hind femora dorsally gently angulate and with a distal carina; the carina more impressed on the hind femora.

Sculpture. Head dorsum minutely punctate and with deep, large, irregular, contiguous foveae; some specimens with the foveae less regular and separate by oblique rugosities. Internal border of the disc strongly punctate occasionally superimposed to irregular, short rugosities. Floor and sides of the disc often completely covered by a thick layer of probable camouflage material; when uncovered the internal surface of the disc shining. Sides of the disc densely and irregularly foveolate-rugulose, more superficially on the anterior half. Ventral part of the head shining, punctate and with irregular longitudinal rugosities. Mesosoma punctate and with dense, irregular foveae. Pedicel with sculpture similar to the one on the mesosoma but the foveae shallower and smaller. Pleurae reticulate and with superimposed irregular foveae on the dorsal half of the propleurae and upper border of the metapleurae; rugosities between the foveae in large specimens only. Gaster and legs with sculpture similar to the worker.

Pilosity. Foveae on the head dorsum with a suberect, slightly clubbed hair; those on the mesosoma, pedicel, gaster and legs with an appressed or decumbent hair. Borders of the disc and foveae on the sides of the head with erect, long, clavate hairs. Vertexal angles, pronotum, pedicel, gastral tergites and legs with rare, clubbed hairs. First gastral sternite with pointed hairs similar to those of the worker. Body parts without foveae with sparse, appresscd, thin, short hairs.

Colour. Brown to black.

Measurements (in mm) and indices: TL 5.08-6.87; HL 1.40-1.88; HW 1.30-1.64; EL 0.30-0.31; PW 1.24-1.56; PeW 0.63-0.69; PpW 0.55-0.67; HBaL 0.26-0.32; HBaW 0.12-0.14; CI 87.2-92.8; PI 104.8-109.4; PPeI 196.8-226.1; PPpI 225.4-232.8; HBaI 43.7-48.1.

Queen
Differing from the soldier in the following characters. Sides of the disc with lower border. Median depression on the vertex deeper.

Mesosoma. Humeral angles obtuse. Pronotal carina less evident and lower. Pronotum, mesonotum and scutellum flat in side view. Sides of the basal face of the propodeum anteriorly convex and posteriorly with a pair of teeth slightly diverging externally and separate by a deep incision.

Anterior face of the petiole oblique and gently concave medially. Petiolar sides with a pair of small denticles. Postpetiole convex; its sides with a pair of broad, short spines pointed posteriorly.

Gastral anterior lobes more developed.

Legs as in the soldier.

Sculpture. As in the soldier but the transversal rugosities on the floor of the disc are unknown. Foveae on the propodeum smaller. Upper and center of the lower mesopleurae with dense, small foveae, more regular on the upper mesopleurae.

Pilosity. As in the soldier except for the clubbed hairs on the pedicel, on the gaster, on the legs and on the mesosoma, slightly denser.

Colour. As in the soldier.

Measurements (in mm) and indices: TL 7.32-7.72; HL 1.52; HW 1.40-1.42; EL 0.36; PW 1.32-1.42; PeW 0.54-0.60; PpW 0.66-0.72; HBaL 0.38-0.40; HBaW 0.15-0.18; CI 92.1-93.4; PI 100.0-106.1; PPeI 237.5-244.4; PPpI 183.7-215.1; HBaI 39.5-45.0.

Male
Similar to the other species of the group from which it differs for one or more of the following characters. Frontal carinae strongly raised and convex. Clypeus gently convex posteriorly and not incised anteriorly. Pronotum in dorsal view with traces of scapular angles.

Sculpture. Head dorsum minutely reticulate, irregularly foveolate-rugose, the rugae oriented transversally in front of the eyes and between the scapes. Ventral part of the head reticulate; its posterior sides rugulose-foveolate, the rugae oblique and the foveae small; ventral part of the head medially with longitudinal rugosities. Pronotum minutely reticulate and with foveae separate by few, thin rugosities on the sides. Mesonotum slightly shining and with minute, superficial reticulation and with superficial, sparse foveae, the reticulation more impressed and the foveae smaller on the posterior part, both structures superimposed by thin, longitudinal rugosities. Scutellum with sculpture similar to the one on the posterior part of the mesonotum but with denser rugosities. Basal face of the propodeum reticulate and longitudinally rugulose. Propleurae reticulate. Mesopleurae superficially reticulate and with thin, longitudinal rugosities on the posterior half, covered by superficial foveae on the center of the lower and of the upper mesopleurae. Metapleurae reticulate and irregularly rugose; the rugosities oriented longitudinally on the lower part. Pedicel superficially reticulate and with thin rugosities on the sides. Gaster superficial!y reticulate and shining.

Pilosity as in the other species of the group.

Colour. Black. Coxae, proximal part of the femora, pedicel and gaster brown. Legs dark yellow with darker tarsomcres.

Measurements (in mm) and indices: TL 5.04; HL 0.74; HW 0.88; EL 0.35; PW 0.88; PeW 0.35; PpW 0.37; HBaL 0.46; HBaW 0.07; CI 118.9; PI 100.0; PPeI 251.4; PPpI 237.8; HBaI 15.2.

Type Material
Holotype soldier from Guyana labelled: Kartabo, B. G. Jul. Aug. 1920, W. M. Wheeler. Paratypes: 27 workers and 15 soldiers, same data as the holotype MCZC,.

Etymology
In Latin pallidus has the same meaning as pallens, the name of one of the species with which the present had been previously confused.

Determination Clarifications
We listed under this species part of the pallens specimens identified by Kempf (1958 a) after a re-study of the material examined by him. The statement of misidentification of the pallens referred by Wheeler & Holldobler (1985) is equally based on examination of their material.