Cephalotes toltecus

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

De Andrade 1999 Cephalotes OCR - Copy-582 Cephalotes-toltecus.jpg

Nothing is known about the biology of Cephalotes toltecus.

Identification

A member of the wheeleri clade differing from its sister species, Cephalotes wheeleri, in the worker by the less regular body rugosities, and in the soldier by the presence of a low, broad tumulus in the middle of the head and by the denser foveae. Soldiers of both species share the posterior part of the disc flat.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Mexico (type locality).

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.

  • toltecus. Cephalotes toltecus De Andrade, in De Andrade & Baroni Urbani, 1999: 579, figs. 269, 270 (s.w.) MEXICO.

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

Description

Worker

Vertexal angles round, with superficially crenulate border. Vertexal border straight and not marginate medially. Hypostoma not connected by a bridge. Cheeks feebly marginate dorsally. Frontal carinae with a superficial incision over the eyes. Antennal scrobes reaching the antero-ventral border of the eyes. Clypeus anteriorly concave. Mandibles with inconspicuous lateral carinae.

Mesosoma gently convex in profile. Pronotum in dorsal view with the anterior border not marginate and convex. Scapular angles absent or not visible in dorsal view. Pronotum with a narrow lamella with three pairs of lateral teeth, the first, humeral, pointed, short and followed by another, smaller, obtuse pair and by a third pair, large, broad and round; the third pair bidentate in some specimens. Sides of the mesonotum converging posteriorly and unarmed. Promesonotal and propodeal sutures superficially impressed only on the sides in dorsal view. Propodeum continuously sloping posteriorly, without distinctly differentiate basal and declivous faces, with a pair of pointed, thin spines directed laterally and slightly upwards at midlength.

Petiole anteriorly truncate; its anterior border marked by a transversal carina variably impressed. Petiolar spines arising from the center of the petiolar sides, shorter than half of the length of the petiole, thin, and pointing backwards. Postpetiole broader than petiole, with thin, pointed spines slightly more than half of the length postpetiole, arising anterolaterally and curved backwards at the base.

Gaster oval, without crest, but superficially marginate on its whole length.

Hind and mid femora without angle or denticles; mid and hind basitarsi long and without flat and broad base.

Sculpture. Head dorsum reticulate, superficially and irregularly foveolate, the foveae denser, deeper and separated by broad reticulation on the posterior third. Frontal carinae much more superficially reticulate than the remaining head dorsum. Ventral face of the head longitudinally striato-rugose. Mesosoma and pedicel reticulate, irregularly foveolate, the foveae separated by broad reticulation anteriorly and with superimposed longitudinal rugosities on the mesonotum and on the propodeum and, on the pedicel among the small specimens. First gastral tergite and sides of the first gastral sternite minutely reticulate and longitudinally rugose, the rugosities more concentric on the middle of the tergite of small specimens; first gastral tergite laterally and center of the first gastral sternite superficially reticulate and shining. Legs reticulate with slightly shining femora. Outer face of the tibiae with oval and superficial foveae.

Pilosity. Body with four types of hairs: (1) sparse, long, erect and truncate, on the head, on the mesosoma, on the pedicel, on the gastral tergites and on the legs; (2) similar to type (1) but thinner and shorter on the gastral sternites; (3) canaliculate, appressed, thick, denser on the vertexal border, on the mesosoma and on the pedicel originating from the foveae; (4) similar to type (3) but shorter and thinner on the frons, on the gaster and on the legs.

Colour. Dark brown to black. Frontal carinae yellow and semi-transparent in small and opaque and darker in larger specimens. Antennae, pronotal, propodeal and pedicellar spines and legs reddish-brown. Vertexal angles, propodeum and pedicel with weak golden reflexes due to the pilosity.

Measurements (in mm) and indices: TL 4.16-5.76; HL 0.96-1.28; HW 1.04-1.38; EL 0.28-0.36; PW 0.85-1.28; PeW 0.48-0.68; PpW 0.52-0.80; HBaL 0.40-0.60; HBaW 0.09-0.12; CI 107.8-108.3; PI 107.8-122.3; PPeI 177.1-188.2; PPpI 160.0-163.5; HBaI 20.0-22.5.

Soldier

Head disc present. Floor of the disc concave anteriorly, flat posteriorly and with a low tumulus in the middle. Frontal carinae broadly expanded anteriorly, not covering the eyes, converging posteriorly and connected by a sharp, convex, not raised carina on the vertex. Vertexal angles round and marginate. Eyes moderately convex. Clypeal border deeply concave anteriorly. Mandibles laterally carinate and largely hidden by the frontal carinae.

Mesosoma. Humeral angles with a broad, obtuse tooth anteriorly, their sides converging posteriorly. Pronotal carina well marked and superficially interrupted in the middle. Promesonotal suture impressed. Mesonotal sides with a broad, pointed or angulate tooth. Lower mesopleurae without minute denticles. Propodeum with differentiate basal and declivous faces; basal face in dorsal view weakly convex, with a broad, pointed tooth in the middle of each side and narrowing towards the declivous face; declivous face longitudinally concave and bearing a pair of small teeth.

Petiole with distinctly differentiate anterior and posterior faces; anterior face truncate, weakly concave medially; posterior face sloping backwards and bearing laterally a pointed spine directed backwards. Postpetiole broadly convex; postpetiolar spines arising from the anterior border of the postpetiole and slightly curved backwards.

Gaster with a reduced border protruding anteriorly and laterally not marginate.

Legs. Fore coxae with a tumulus anteriorly. Mid and hind femora without angle or denticles. Mid and hind basitarsi without broad base and not compressed laterally.

Sculpture. Head, mesosoma and pedicel superficially and minutely reticulate and foveolate, the foveae deep and broader than their interspaces on the head dorsum, slightly sparser on the anterior half of the pronotum and on the middle of the propodeum, smaller and shallower than on the head dorsum on the posterior half of the pronotum and on the middle of the mesonotum, dense on the sides of the mesosomal dorsum and on the pedicel. Frontal carinae superficially reticulate-foveolate and little shining. Ventral part of the head with the same sculpture as on the anterior part of the pronotum and superficially shining. Pleurae, declivous face of the propodeum, legs, first gastral tergite and sides of the first gastral sternites reticulate; the same sculpture but less impressed than on the legs and more shining on the remaining tergites, sternites and on the middle of the first sternite. Propleurae, lower mesoand metapleurae and outer face of the femora and tibiae with superficial foveae, more irregular on the tibiae. Anterior third of the first gastral tergite and the sides of the first gastral sternites with faint longitudinal rugosities.

Pilosity. Body with four types of hairs: (1) canaliculate, decumbent to appressed arising from each fovea, longer and thicker on the propodeum, on the pedicel and on the lower part of the meso- and metapleurae, slightly shorter and thinner on the extensor face of the legs; (2) long, erect, truncate, rare on the mesosoma and on the pedicel, sparse on the first gastral tergite and on the legs, dense on the posterior border of the gaster; (3) similar to type (2) but shorter and thinner on the first gastral sternite; (4) minute, appressed and thin on the gaster and on the anterior and posterior faces of the legs.

Colour. Black. Frontal carinae dark red. Legs ferruginous with brown first tarsomere and lighter remaining tarsomeres.

Measurements (in mm) and indices: TL 5.96-7.20; HL 1.48-1.64; HW 1.64-1.72; EL 0.34-0.36; PW 1.60-1.68; PeW 0.66-0.68; PpW 0.74-0.76; HBaL 0.46-0.52; HBaW 0.12; CI 104.9-110.8; PI 102.4-102.5; PPeI 242.4-247.0; PPpI 216.2-221.0; HBaI 23.1-26.1.

Type Material

Holotype soldier from 19 mi. NW Magdalena, Jalisco, Mexico, Museu de Zoologia da Universidade de Sao Paulo; paratypes: 3 soldiers and 6 workers, same data as the holotype, all in Museu de Zoologia da Universidade de Sao Paulo.

Etymology

This species is named after the Toltecs, one of the ancient peoples of south Mexico.

References

  • de Andrade, M. L.; Baroni Urbani, C. 1999. Diversity and adaptation in the ant genus Cephalotes, past and present. Stuttgarter Beitrage zur Naturkunde Series B (Geolgie and Palaontologie). 271:1-889. (page 579, figs. 269, 270 soldier, worker described)