Cephalotes betoi

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Cephalotes betoi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. betoi
Binomial name
Cephalotes betoi
De Andrade & Baroni Urbani, 1999

Nothing is known about the biology of Cephalotes betoi.

Identification

A member of the depressus clade characterised in the worker, soldier and gyne by the pleurae and the declivous face of the propodeum with longitudinal rugosities, in the worker by the broad, long, incised pronotal lamellae and by the petiole anteriorly angulate, and, in the soldier, by the incomplete disc, by the triangular pronotal lamellae, and, in the gyne, by the absence of disc, by the fuscous frontal carinae and by the few hairs on the lower metapleurae. The worker of betoi is very similar to that of Cephalotes pavonii. The longitudinal rugosities on the pleurae and on the declivous face of the propodeum in both neuter castes and the other characters mentioned above separate betoi from all others in the clade. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), Ecuador.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

The biology of many Cephalotes species is not known. Ants in this genus are common in the New World tropics and subtropics and are especially abundant and diverse in the canopies of Neotropical forests. The majority of species are arboreal. Species that live in other strata inhabit smaller trees, bushes or grass stems. These noon-arboreal species, due to their accessibility, are among the better studied members of the genus. There are also species that can be found in downed wood but it is likely the wood housed the colony before it fell to the ground. Soil nests are not known for any species nor do most species appear to extensively excavate plant tissue. They nest instead in preformed cavities. Overall, ants in the genus utilize a wide range of plants. Some species are predictable in their plant use but none appear to have evolved specialized mutualisms with particular plant species.

Worker castes typically include two forms, a worker and soldier, but there are a few species that are monomorphic. The larger soldier caste typically has an enlarged head disk. In some species the head of the soldier is very different from the worker while in others these differences are less pronounced. Queens and soldiers tend to share similar head morphology. Soldiers use their heads to plug the nest entrance. This can be very effective in excluding potential intruders. Other morphological differences between the worker castes are present but these differences have not been studied as well as head moprhology.

The behavioral repertoire of Cephalotes varians has been examined in great detail (ethograms from Wilson 1976, Cole 1980 and Cole 1983). Soldiers do little else besides defend the nest. This specialized soldier behavior is presumed to be the norm for most species. An especially interesting behavior occurs when workers are dislodged from trees: they "fly" towards the tree, often grabbing the trunk well above the ground (video).

Mature nest size varies, by species, from less than a hundred to many thousands of workers. Available evidence suggests most species are monogynous. Queens may mate with multiple males.

The proventriculus of the Cephalotes is peculiar relative to other ants. The morphology of the structure suggests it serves as a powerful pump and filter. This does not appear to lead these ants to have a highly specialized diet as most species appear to be general scavengers. Foragers have been observed feeding on carrion, bird feces, extrafloral nectaries and even tending membracids. Pollen feeding has been observed in some species, and this is somewhat specialized for ants, but it is not evident that any species restricts its diet to this resource in any significant way. Evidence for pollen feeding in Cephalotes has accumulated, in part, via finding digested pollen grains seen in infrabucal pellets. It has been suggested that the morphology of the proventriculus is a specialization for processing pollen.

More research examining all aspects of the biology of Cephalotes is needed. Our present understanding of these ants is largely based on species that live in locations other than the forest canopy, which is where Cephalotes are most common and diverse.

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • betoi. Cephalotes betoi De Andrade & Baroni Urbani, 1999: 347, figs. 153, 154, 386 (s.w.) BRAZIL. [Cephalotes betoi Baroni Urbani, 1998: 326. Nomen nudum.]

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

Head subquadrate. Vertexal corners with two pairs of teeth, the external pair small, obtuse or simply a convex margin, the internal ones large, triangular and lamellaceous. Vertex marginate and deeply concave. Cheeks completely marginate below. Frontal carinae broad, strongly upturned over the eyes and extending up to their posterior border backwards. Antennal scrobes reaching the anterior border of the eyes. Clypeal border broadly incised. Mandibles with lateral carinae; the masticatory margin with an apical and a subapical tooth followed by 0-4 denticles. Eyes strongly convex.

Mesosoma convex in side view. Scapular angles well visible in dorsal view. Pronotal sides with broad lamellae; the lamellae directed antero-laterally, their sides bidentate or crenulate, their posterior border converging, with a small notch on the middle. Mesonotal teeth pointed. Propodeal suture variably impressed dorsally. Propodeum sloping backwards and slightly concave, without differentiate basal and declivous faces; its sides with two pairs of semilamellaceous spines, the anterior p air broad and with obtuse tip, the posterior one smaller, variably broad, and pointed. Petiole ca. 1/4 broader than postpetiole, its anterior border with a median concavity. Petiolar spines curved backwards, variably pointed, their sides not continuous with the anterior border of the petiole. Postpetiolar spines curved with the apices pointing backwards.

Gaster with a broad lamellaceous anterior border reaching the first gastral stigma at least.

Hind and mid femora denticulate in the middle; mid and hind basitarsi laterally compressed.

Sculpture. Head dorsum, mesosoma and abdominal pedicel covered by reticulation and foveae, the foveae smaller and sparser on the anterior half of the head, on the posterior half of the propodeum and on the abdominal pedicel. Ventral face of the head reticulate, with superimposed rugosities from the eyes and converging to the submentum. Propodeum with faint, irregular rugosities on its posterior half. Sides of the mesosoma with longitudinal rugosities and reticulate. First gastral tergite reticulate and with small, superficial foveae anteriorly. Corresponding sternite reticulate and slightly shining in the middle. Fore coxae reticulate and variably rugulose; mid and hind coxae with longitudinal rugosities. Femora and tibiae reticulate and with foveae as on the anterior part of the first gastral tergite.

Pilosity. Each fovea bearing an appressed hair whose size is proportional to that of the fovea. Sides of the head, of the mesosoma, mandibles, legs, and gaster with short, clavate hairs. Sternites with sparse, long, suberect, truncate hairs.

Colour. Black. Frontal carinae, antennae, masticatory margin of the mandibles, borders of the pronotal lamellae, propodeal, and pedicular spines, gastral membranes, tibiae and tarsi, dark orange to light brown.

Measurements (in mm) and indices: TL 4.64-4.88; HL 1.08-1.16; HW 1.32-1.44; EL 0.36-0.38; PW 1.32-1.48; PeW 0.84-0.92; PpW 0.64-0.70; HBaL 0.36-0.40; HBaW 0.11-0.13; CI 122.2-127.3; PI 97.3-106.1; PPeI 153.5-160.8; PPpI 197.0-211.4; HBaI 30.5-33.3.

Soldier

Head subquadrate, with an incomplete disc. Vertexal corners with two pairs of short, obtuse teeth. Head dorsum convex. Posterior border of the disc with a pair of developed median teeth connected each other by a median ridge continuing superficially on the sides of the head into the frontal carinae. Frontal carinae with crenulate border and converging posteriorly. Mandibles broad, their sides with an impressed, round, carinate protuberance. Eyes gently convex.

Mesosoma broad anteriorly, narrowing posteriorly. Scapular angles little protuberant. Pronotal sides converging posteriorly, bearing a pair of developed, triangular, humeral angles. Pronotal carina well marked, raised, strongly crenulate and interrupted medially by an impression. Promesonotal suture impressed. Mesonotal sides with a pair of broad, short, obtuse or round tooth. Propodeal suture deeply impressed. Propodeum with poorly differentiated basal and declivous faces. Basal face broadening posteriorly and ending in a pair of broad, developed, rectangular bidentate lamellae, its dorsum convex in the middle and on the same plane as the declivous face. Declivous face flat in the middle, its sides converging posteriorly and bearing medially a pair of triangular, lamellaceous teeth.

Petiolar node sloping anteriorly; its anterior border concave. Petiolar sides diverging posteriorly, with a median, well developed spine directed backwards. Postpetiole, in lateral view, slightly convex, dorsally gently concave; p ostpetiolar spines thick, arising from the anterior face and curved backwards.

Gaster oval and with a broad anterolateral lobe. Anterolateral border of the first gastral tergite with a thick margin reaching the stigma.

Hind femora medially angulate. Hind basitarsi flat and with broad base.

Sculpture. Head superficially punctate and covered by small, variably clumped foveae, diminishing in size anteriorly. Vertexal corners, ventral face of the head, pronotum and mesonotum with foveae larger and deeper than those on the posterior part of the head. Basal face of the propodeum, posterior half of the meso- and metapleurae, petiole, postpetiole, legs and anterior fourth of the first gastral tergite reticulate and with dense, oval foveae. Remaining pleural parts reticulate and with thin, longitudinal rugosities. Declivous face of the propodeum reticulate and with irregular, longitudinal rugosities.

Remaining gastral tergites with small piligerous punctures; this same type of sculpture but sparser on the sternites; centre of the first gastral sternite slightly shining.

Pilosity. As in the worker.

Colour. Black. Frontal carinae dark ferruginous, tarsomeres, tip of the last funicular joints, of the humeral angles, and of the peduncular segments ferruginous.

Measurements (in mm) and indices: TL 6.36-7.32; HL 1.56-1.80; HW 1.96-2.26; EL 0.44-0.48; PW 1.92-2.24; PeW 0.96-1.10; PpW 0.78-0.92; HBaL 0.44-0.50; HBaW 0.17-0.20; CI 125.0-125.6; PI 98.2-100.9; PPeI 200.0-215.4; PPpI 243.5-266.6; HBaI 36.0-40.0.

Queen

Head subquadrate, dorsally convex. Frontal carinae crenulate, expanded anteriorly, converging posteriorly before the eyes, upturned above them and gently diverging posteriorly to the vertexal angles. Vertexal angles externally with a pair of minute denticles and internally with a pair of broad, obtuse teeth. Vertex bearing a pair of dorsal denticles. Mandibles with a thick lateral carina.

Mesosoma. Scapular angles short and visible i n dorsal view. Humeral angles with a pair of pointed teeth. Pronotal sides straight. Pronotal carina marked, superficially crenulate on the sides only, and interrupted on the middle by a superficial depression. Mesonotum and scutellum flat in side view. Lower mesopleurae with traces of a small denticle. Basal face of the propodeum short. Sides of the basal face of the propodeum with two pairs of teeth, the anterior pair round and small, the posterior pair more pointed. Sides of the declivous face of the propodeum converging posteriorly.

Petiole with deeply concave anterior face and anteriorly declivous dorsally; anterior half of the petiolar sides diverging into a pair of pointed teeth, the posterior half converging posteriorly. Postpetiole broadly convex dorsally; sides of the postpetiole with a pair of broad spines arising from the anterior border and curved backwards.

Gaster weakly protruding anteriorly and with the margination not reaching the first stigma posteriorly.

Legs. Fore coxae angulate. Hind femora angulate. Mid and hind basitarsi compressed laterally, their proximal part broader than the distal one.

Sculpture. Dorsum of the head, of the pronotum, of the mesonotum and of the scutellum minutely punctate and with variably clumped foveae, diminishing in size on the anterior half of the head, shallower on the frontal carinae, larger on the pronotum. Ventral part of the head with sculpture similar to the one on the pronotum but with the foveae deeper on the sides. Basal face of the propodeum, pedicel and upper mesopleurae with irregular, dense, foveae. Propleurae reticulate and with foveae anteriorly and superiorly only; propleurae with additional longitudinal, thin rugosities on the posterior third. Lower mesopleurae reticulate and with foveae on the borders only; their centre with thin, faint, longitudinal rugosities. Metapleurae reticulate and with longitudinal rugosities. Outer face of the fore and hind coxae with short, transversal, thin, rugosities. Outer face of the mid coxae with longitudinal, thin rugosities. Gaster and legs reticulate. Anterior third of the first gastral tergite with irregular, superficial foveae; outer face of the distal part of the femora and the outer face of the tibiae with sculpture similar to the one of the first gastral tergite but with smaller foveae.

Pilosity. As in the other species of the clade.

Colour. Black with lighter legs. Frontal carinae opaque, dark ferruginous to brown.

Measurements (in mm) and indices: TL 10.22; HL 1.88; HW 2.12; EL 0.50; PW 2.08; PeW 0.98; PpW 1.12; HBaL 0.62; HBaW 0.24; CI 112.8; PI 101.9; PPeI 212.2; PPpI 185.78; HBaI 38.7.

Type Material

Holotype, worker from Reserva Biologica de Aguas Emendadas, Distrito Federal, Brazil, 27-30.VI.1991, C. R. F. Brandao, M. L. Francoso & A. A. Reis, in Museu de Zoologia da Universidade de Sao Paulo; paratypes 182 workers and 12 soldiers, same data as the holotype, in MZSP.

Etymology

This species is named after "Beto", the nickname of Prof. Carlos Roberto Ferreira Brandao, the collector of most of the material on which this species is based.

References

  • de Andrade, M. L.; Baroni Urbani, C. 1999. Diversity and adaptation in the ant genus Cephalotes, past and present. Stuttg. Beitr. Naturk. Ser. B (Geol. Paläontol.) 271: 1-889 (page 347, figs. 153, 154, 386 soldier, worker described)