Cephalotes auricomus

Known from a number of collections from the Dominican Republic.

Identification
A member of the hamulus clade characterised by the following apomorphy: posterior fourth of the head dorsum, mesosoma and pedicel covered by dense, thick, golden hairs. Cephalotes auricomus is easily distinguished by the pilosity covering most of the body sculpture. Its closest relative is the fossil Cephalotes resinae. Both species share - together with Cephalotes hamulus - the black body and the thick, longitudinal striae on the ventral side of the head. Auricomus, however, differs from resinae by its much thicker pilosity over the whole body, and from Cephalotes hamulus the absence of longitudinal rugae on the anterior fourth of the first gastral tergite and by its much denser hairs. C. auricomus also shares with Cephalotes unimaculatus and Cephalotes vinosus the ventral part of the sides of the head with thick, longitudinal striae, but unimaculatus and vinosus have different gastral coloration and less abundant pilosity. (de Andrade and Baroni Urbani 1999)

Distribution based on Regional Taxon Lists
Neotropical Region: Dominican Republic, Greater Antilles, Haiti.

Known only from the type country.

Biology
Baroni Urbani and de Andrade (1999) - A presumably complete nest of C. auricomus collected in a dead branch of a tree close to Puerto Plata (Dominican Republic) on June 2, 1995. It contained one queen, 520 eggs, 192 larvae of different ages, 69 worker pupae, 10 gyne pupae, 75 male pupae, 483 workers, 24 gynes, and 151 males. We suppose, however, that at least 5% of the population (particularly males which flew away) may have been lost during the nest dissection in the field. Summing all the adults and pupae of the same sex or caste give a male-biased secondary sex ratio of 10:1.

Nomenclature

 * . Hypocryptocerus haemorroidalis susbp. auricomus Wheeler, W.M. 1936b: 202 (w.) DOMINICAN REPUBLIC.
 * Type-material: syntype workers (number not stated, “numerous”).
 * [Note: De Andrade & Baroni Urbani, 1999: 89, report 13 syntypes.]
 * Type-locality: Dominican Republic: Sanchez, v.1915 (F.E. Watson).
 * Type-depositories: MCZC, MZSP.
 * De Andrade & Baroni Urbani, 1999: 91 (q.m.).
 * Combination in Zacryptocerus: Brandão, 1991: 384;
 * combination in Cephalotes: Baroni Urbani, 1998: 328.
 * Subspecies of haemorrhoidalis: Kempf, 1951: 148; Kempf, 1972a: 120; Brandão, 1991: 384; Bolton, 1995b: 424.
 * Status as species: De Andrade & Baroni Urbani, 1999: 89 (redescription); Lubertazzi, 2019: 99.
 * Distribution: Dominican Republic.

Worker
de Andrade and Baroni Urbani (1999) - Vertexal angles round, with crenulate margin; vertexal margin gently concave. Vertex with a trace of transversal carina and medially with a pair of small denticles more protruding in larger individuals. Eyes convex. Remaining cephalic morphology as in hamulus.

Mesosoma robust, convex in side view. Scapular angles rounded or with a small spine. Anterior pronotal border marked by a faint carina more impressed in smaller individuals. Humeral angles with a pair of obtuse or pointed spines directed anteriorly. Pronotal sides straight, ending posteriorly in a small tooth visible in dorsal view. Promesonotal suture variably impressed. Mesonotal teeth absent or minute and round. Propodeal suture deeply impressed dorsally. Propodeum with differentiate basal and declivous faces. Basal face more than 1/3 broader than long, with slightly convex sides anteriorly, straightening posteriorly and with or without a small denticle; declivous face as long as the basal face, with slightly converging sides posteriorly. Propodeal spines sub equal in length to the basal face of the propodeum, generally thin and diverging.

Petiole ca. 1/2 broader than long, its anterior face truncate and slightly concave; its sides converging posteriorly and bearing anteriorly a small spine and medially a pointed tooth of variable size. Postpetiole broader and longer than the petiole; postpetiolar spines broad and variably pointed, inserted anteriorly and curved backwards.

Gaster and legs as in hamulus.

Sculpture. Head minutely reticulate; vertexal area covered by broad impressions or irregular foveae gradually shallower towards the cheeks, sparser on the anterior half of the head.

Mesosoma, petiole and postpetiole covered by strong, longitudinal, irregular striae and superficial reticulation less impressed on the pronotum. Declivous face of the propodeum completely or partially covered by thick, longitudinal striae and reticulation.

First gastral tergite reticulate without longitudinal rugosities on part or on the whole of its surface. Corresponding sternite with superficial longitudinal rugosities on the sides, the rest with impressed reticulation, opaque or faintly reticulate and slightly shining in the middle.

Coxae with sparse, transversal or longitudinal rugosities and punctate, sometimes only reticulate. Remaining parts of the legs as in hamulus. Pilosity. Body with the following types of hairs: (1) truncate, erect to suberect, long on the vertexal area, on the mesosoma and on the pedicel, shorter on the anterior part of the head, on the gaster and on the legs; (2) thick, dense and appressed, long on the vertexal area, on the mesosoma and pedicel, shorter, thinner and sparser on the two anterior thirds of the head dorsum, on the extensor face of the femora and on the gastral tergites; (4) thin, appressed and short on the legs, on the sternites, and on the ventral sides of the first tergite; (5) thin, pointed, erect, sparse and long on the gastral sternites. Colour. Black. Frontal carinae and scapes dark orange to light brown. Posterior fourth of the head dorsum and propodeum with golden reflexes.

Measurements (in mm) and indices: TL 5.72-7.04; HL 1 .44-1 .72; HW 1 .52-1 .96; EL 0.44-0.54; PW 1 .40-1. 80; PeW 0.64-0.80; PpW 0 .75-0.92; HBaL 0.60-0.76; HBaW 0. 1 6-0.2 1; C I 1 05.5-1 1 3.9; P I 1 06.3-1 14.3; PPeI 200.0-256.2; PPpl 1 78.7-1 95.6; HBal 26.3-29.4.

Queen
de Andrade and Baroni Urbani (1999): (previously undescribed) - Head subquadrate and convex, without disc. Frontal carinae not covering completely the cheeks. Vertexal angles subround, with crenulate margin; vertexal margin gently concave medially. Vertex with a pair of median denticles and with a trace of transversal carina in some specimens only. Ocelli far from the vertexal border. Middle of the head dorsum with a superficial depression. Clypeus concave anteriorly. Mandibles without lateral, carinate tumulus. Cheeks marginate.

Mesosoma. Scapular angles visible in dorsal view. Humeral angles with a pair of pointed anterior teeth. Pronotal sides straight. Pro notal carina strongly marked by a row of pointed denticles, shortly interrupted in the middle only. Mesonotum and scutellum flat to convex. Lower mesopleurae with a stout denticle. Basal face of propodeum converging posteriorly and with a pair of teeth; declivous face flat. Petiole with the anterior face truncate and oblique; its sides converging posteriorly and unarmed. Postpetiole convex dorsally, with the sides convex anteriorly, converging posteriorly and unarmed. Gaster with a broad anterior border but without true anterior lobes.

Legs as in the worker.

Wings. Fore wings with R+Sc superficially connected to a marked pterostigma. 2r marked, Rsf5 connected with RI. Distal parts of A, Cu-AI and Mf4 vestigial. Hind wings with R, M+CuA, M and IA marked; distal part of M, of CuA and of lA vestigial.

Sculpture. Vertexal area irregularly foveolate-rugulose, this sculpture is substituted anteriorly by dense, small foveae superimposed to minute reticulation. The foveae more regular and deeper on the posterior half of the frons. Ventral side of the head laterally covered by thick, regular or irregular striae and reticulate; the striae on the anterior half are substituted by foveae in some specimens. Hypostomal area deeply reticulate and with sparse, superficial foveae. Cheeks reticulate and foveolate.

Mesosoma and pedicel reticulate and covered by foveae of irregular shape, sometimes also with additional irregular rugosities. Mesopleurae with foveae more regular than on the other mesosomal parts. Metapleurae reticulate and with few, faint rugosities. Declivous face of the propodeum reticulate and with or without longitudinal rugosities. First gastral tergite and sternite reticulate and with small, superficial, piligerous punctures. Central part of the first gastral sternite moderately shining.

Pilosity as in the worker but with the appressed hairs slightly thinner and shorter.

Colour. Black. Frontal carinae and scapes dark ferrugineous. Golden reflexes less than in the worker.

Measurements (in mm) and indices: TL 9.78-1 0.00; HL 1 .96-2.00; HW 2.04-2. 1 6; EL 0.53-0.55; PW 2 .08-2.20; PeW 0.70-0.74; PpW 0.80-0.8 1 ; HBaL 0.80; HBaW 0.23-0.24; CI 1 04. 1 -1 08.0; PI 98.1-98.2; PPeI n7. 1 -297.3; PPpl 256.8-275.0; HBal 28.7-30.0.

Male
de Andrade and Baroni Urbani (1999): previously undescribed - Head (eyes included, mandibles excluded) about 1/3 broader than long; vertexal margin marked as an interruption of the sculpture, straight and ending in gently convex angles. Behind the vertexal margin the head narrows in a short but visible "neck". Vertex convex. Ocelli protuberant. Eyes convex, in the middle of the sides of the head. Frontal carinae converging anteriorly, diverging backwards and not reaching the posterior border of the eyes. Frons flat, slightly concave in the middle and separate from the clypeus by a furrow. Clypeus convex, its posterior half higher than the anterior one, almost truncate. Mandibles without lateral carina. Scapes thick, twice as long as the first funicular joint; remaining funicular joints thickening from the base to the apex.

Mesosoma. Pronotum in dorsal view with strongly convex anterior border, broadening backwards, superficially carinate on the sides and with marked scapular angles; mesonotum convex; median Mayrian carina and parapsidal furrows weakly impressed; scutellum convex, its sides converging posteriorly; propodeum with differentiate basal and declivous faces; basal face with the sides converging posteriorly and with a pair of pointed teeth; declivous face with converging sides and laterally carinate.

Petiole narrower than the postpetiole and with the anterior border gently concave; its dorsum flat and gently sloping anteriorly; petiolar sides convex anteriorly and narrowing posteriorly. Postpetiole almost flat and with a superficial concavity dorsally; anterior third of the postpetiolar sides with a pair of short, pointed teeth.

Gaster almost as broad as the mesosoma.

Genitalia and subgenital plate as in Fig. 30.

Wings as in Fig. 31.

Sculpture. Head and mesosoma reticulate; this sculpture is superimposed by irregular, small foveae and irregular rugosities less impressed on the frons. Metapleurae, declivous face of the propodeum, petiole and postpetiole superficially reticulate and with thick striae, more regular on the pedicel, thinner and fainter on the postpetiole. First gastral tergite strongly reticulate, some specimens with thin, faint, short rugulosities on the anterior fourth. Remaining tergites and sternites superficially reticulate and shining. Legs punctate, the punctuations more impressed and denser on the tibiae. Pilosity. Head and mesosoma covered by dense, long, sub erect hairs, the same hairs sparser on the pedicel, on the gaster and equally sparse and shorter on the legs. Legs and gaster with other, similar but thinner and shorter hairs, appressed. Funiculi densely covered by thin, short, decumbent hairs.

Colour. Head, mesosoma, peduncular segments and coxae black. Mandibles and antennae, brown, first gastral segment ferrugineous. Scape, first funicular joint, masticatory margin of the mandibles, gaster and legs dark orange; proximal half of the femora and remammg funicular joints darker.

Measurements (in mm) and indices: TL 7.06-7.20; HL 1 .04-1 .08; HW 1 .20-1 .24; EL 0.50-0.52; PW 1 .12-1. 1 6; PeW 0.50-0.5 1; PpW 0.58-0.60; HBaL 0.87-0.89; HBaW 0.13; CI 1 1 1. 1-1 1 9.2; PI 1 03.4-1 1 0.7; PPe! 2 1 9.6-232.0; PPpI 1 93.1-1293.3; HBaI 14.6-14.9.

Type Material
de Andrade and Baroni Urbani (1999): Sanchez (Dominican Republic). Type material: 12 syntype workers in the, 1 syntype worker in , all examined.

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Kempf W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Revista de Entomologia (Rio de Janeiro) 22:1-244
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Perez-Gelabert D. E. 2008. Arthropods of Hispaniola (Dominican Republic and Haiti): A checklist and bibliography. Zootaxa 1831:1-530.
 * Wheeler, William Morton. 1936. Ants From Hispaniola and Mona Island. Bulletin: Museum of Comparative Zoology at Harvard College. 80(2):192-211.
 * de Andrade, M.L. & C. Baroni Urbani. 1999. Diversity and Adaptation in the ant genus Cephalotes, past and present. Stuttgarter Beitrage zur Naturkunde Serie B 271. 893 pages, Stuttgart