Cephalotes targionii

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Cephalotes targionii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. targionii
Binomial name
Cephalotes targionii
(Emery, 1894)

Cephalotes targionii casent0173707 profile 1.jpg

Cephalotes targionii casent0173707 dorsal 1.jpg

Specimen labels

Synonyms

Besides knowing some specimens were collected from forest habitat, nothing is known about the biology of Cephalotes targionii.

Identification

A member of the angustus clade differing, in the worker, from Cephalotes conspersus by the dark gaster instead of orange, and, from Cephalotes palta, by the narrower head; and, in the soldier, from conspersus and palta by the denser foveae on the floor of the cephalic disc. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Guyana, Paraguay, Trinidad and Tobago, Venezuela.

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

de Andrade and Baroni Urbani (1999) - We collected and kept in the laboratory a part of a colony from Lins (S. Paulo) with two well differentiated types of gynes: the larger ones had orange head with a brown spot on the frons and the small ones had largely black head. The measurements of one of these dwarf gynes are reported in parentheses after the measurements of the “normal” ones. Our laboratory observations did not reveal behavioural differences among the two types of unfertilised gynes. We have circumstantial evidence that a similar gyne dimorphism should be present also among other Cephalotes species (Cephalotes depressus, Cephalotes jheringi) but we did not discuss these cases under the proper species since we have no unequivocal proof that gynes of different sizes originate from the same nest.

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.

  • denticulatus. Cryptocerus denticulatus Emery, 1894c: 206, pl. 3, fig. 17 (w.) BOLIVIA. Junior synonym of targionii: Kempf, 1958a: 94.
  • targionii. Cryptocerus targionii Emery, 1894c: 205, pl. 3, figs. 15, 16 (s.) BRAZIL. Kempf, 1958a: 98 (q.); De Andrade & Baroni Urbani, 1999: 690. Combination in Paracryptocerus (Harnedia): Kempf, 1958a: 94; in Cephalotes: De Andrade & Baroni Urbani, 1999: 684. Senior synonym of denticulatus: Kempf, 1958a: 94. Junior synonym of conspersus: Kempf, 1958d: 108. Revived from synonymy: De Andrade & Baroni Urbani, 1999: 684.

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

Description

Worker

de Andrade and Baroni Urbani (1999) - Head gently convex above, subquadrate. Frontal carinae diverging backwards, slightly converging in front and upturned above eyes. Vertexal angles truncate and with two pairs of small, obtuse, membranaceous denticles. Vertexal margin slightly concave and laterally connected with the internal pair of denticles through a thin carina. Clypeal suture little impressed. Mandibles with a thin, short lateral carina.

Mesosoma slightly convex. Scapular angles visible in dorsal view. Pronotal sides with three pairs of short, teeth, the first pair, triangular and separated from the second obtuse one by a superficial notch, the third pair broad, truncate, apically crenulate and separated from the two first pairs by a minute notch. Promesonotal suture vestigial or obsolete. Mesonotum with a pair of triangular teeth with obtuse or truncate tip. Propodeal suture more impressed on the sides. Propodeum slightly differentiated in basal and declivous face; declivous face little concave in the middle and as long as the basal one. Propodeal sides with 3 pairs of pointed teeth and with one to three additional pairs of denticles.

Petiole with sloping anterior face; its median dorsum with a pair of denticles. Sides of the petiole with a pointed, thin spine directed backwards. Postpetiole slightly broader than petiole; middle of the postpetiolar dorsum with a V-shaped carina; postpetiolar spines directed forwards at the base and curved at the apex.

Gaster oval. Anterolateral gastral border with a semitransparent lamella not surpassing the level of the stigma.

Hind femora without angle or denticle in the middle.

Sculpture. Head dorsum reticulate and covered by foveae as broad as their interspaces on the two anterior thirds, denser on the last third. Frontal carinae reticulate only. Ventral face of the head reticulate and with slightly impressed longitudinal rugulae. Trunk, posterior face of the petiole, and postpetiole with the same sculpture as on the posterior third of the head dorsum, more oval on the propodeum and less impressed on the pedicel. Middle of the declivous face of the propodeum, anterior face of the petiole, gaster and legs reticulate. Pleurae reticulate and longitudinally striate. First gastric tergite with superficial piligerous foveae. Center of the posterior half of the first gastral sternite shining.

Pilosity. Each fovea with an appressed canaliculate hair, slightly longer on the propodeum and on the pedicel. Mandibles, border of the frontal carinae and legs with sparse, suberect, canaliculate hairs. Legs and gaster with dense, appressed, canaliculate hairs as those on the propodeum, thinner on the gaster. Apex of the tergites and sternites with two types of erect hairs: (1) short, sparse and slightly canaliculate, (2) long, rare and pointed.

Colour. Body black. Frontal carinae, distal part of the scapes, first funicular joint, mesosomal and peduncular spines, anterolateral lamella of the gaster, apex of femora, outer face of the tibiae and tarsomcrcs yellowish to light ferrugineous. First gastral tergite black or with the following patterns of coloration: only the anterior fourth light brown, or anterior fourth and lateral borders light brown, or with a pair of dark yellow spots behind the lamellae.

Measurements (in mm) and indices: TL 3.88-4.70; HL 0.92-1.12; HW 1.08-1.28; EL 0.28-0.32; PW 0.88-1.04; PeW 0.52-0.57; PpW 0.55-0.65; HBaL 0.35-0.44; HBaW 0.09-0.11; CI 112.0-117.4; PI 119.1-123.1; PPeI 169.2-182.4; PPpI 160.0-164.9; HBaI 25.0-25.7.

Soldier

de Andrade and Baroni Urbani (1999) - Head with a complete disc, concave anteriorly and flat posteriorly. Sides of the head disc strongly converging before the beginning of the eyes and connected with the truncate posterior border of the disc. Length of the truncate border less than half of the maximum width of the head. Borders of the head disc strongly marginate and less raised posteriorly. Vertexal angles convex, obtuse and strongly marginate up to the posterior border of the eyes. Clypeal border concave and medially delimited by two denticles. Mandibles with a strong carina. Dorsal border of the antennal scrobes with a thick carina ending in a small denticle just before the eyes. Eyes flat and not hidden by the head disc.

Mesosoma broad and almost flat in side view. Pronotum sloping; its anterior border convex mesially. Humeral angles obtuse. Pronotal sides convex. Pronotal carina thickening from the sides to the center where it is interrupted by a superficial sulcus. Promesonotal suture impressed. Mesonotum with a pair of broad, round tooth. Propodeal suture deeply impressed. Propodeum well differentiated in basal and declivous faces. Basal face medially as high as the mesonotum, laterally lower. Sides of the basal face of the propodeum with a small swelling followed by two pairs of teeth, the first pair short, broad and with almost round tip, the second one large, broad, thick, curved upwards and forwards at the apex and with obtuse tip. Declivous face concave in the middle; its sides converging posteriorly.

Petiole differentiated in anterior and posterior faces; anterior face sloping, separated from the short, declivous posterior face by a faint, transversal carina. Sides of the petiole with a pair of short, thick teeth directed backwards. Postpetiole convex and with a v-shape carina in the middle. Postpetiolar sides with a pair of thick spines arising from the anterior border and directed anterolaterally. Tip of the postpetiolar spines almost round.

Gaster oval, with a broad, protruding anterolateral lobe. Anterolateral border of the first gastral sternite with a very thin margin not reaching the stigma.

Hind femora without angle or denticle in the middle. Hind basitarsi slightly more compressed apically than distally, and without broad base.

Sculpture. Head dorsum reticulate and covered by large foveae broader than their interspaces, larger on the center of the head disc, shallower on the frontal carinae. Sides of the head superficially reticulate and with foveae one third of the size of those on the center of the disc, deeper posteriorly. Ventral part of the head deeply reticulate, its posterior half with larger, shallower and sparser foveae than on its anterior half. Mesosoma reticulate, with foveae almost as broad as those on the side of the head, the foveae are slightly larger and sparser on the pronotum, smaller, deeper and denser on the mesonotum and basal face of the propodeum. Declivous face of the propodeum reticulate and with faint, transversal rugosities. Pleurae reticulate; propleurae with longitudinal striae, this sculpture but less impressed and thinner on the lower metapleurae. Sparse foveae on the meso and metapleurae. Posterior face of the petiole and postpetiole with oval, superficial foveae. Anterior face of the petiole, gaster and legs reticulate. Disc of the posterior half of the first gastral sternite shining.

Pilosity. Each fovea with a subdecumbent or decumbent canaliculate hair, slightly longer and decumbent on the head disc. Legs and gaster with the same appressed hairs as on each fovea, thinner on the gaster. Mandibles and legs with rare, suberect, canaliculate hairs. Apex of the tergites and sternites with two types of erect hairs: (1) short, sparse and slightly canaliculate, (2) long, rare and pointed.

Colour. Ventral part of the head including the ventral third of its sides, clypeus, mesosoma, pedicel, coxae, femora and gaster dark brown to black. Head disc, the two dorsal thirds of the sides of the head, mandibles, sides of the pronotum, propodeal and pedicular spines, apex of femora, outer face of tibiae, tarsomeres and border of the tergites yellowish-orange to ferruginous, with darker antennae and basitarsi. Gaster with two pairs of yellow spots, the first pair anterolaterally, almost round and reaching the stigma, the second one oval and placed on the postero-Iateral half of the gaster and not reaching the posterior border of the first gastric tergite. Body opaque to superficially shining.

Measurements (in mm) and indices: TL 5.16-7.08; HL 1.42-1.92; HW 1.42-1.88; EL 0.32-0.37; PW 1.26-1.72; PeW 0.60-0.76; PpW 0.66-0.80; HBaL 0.38-0.47; HBaW 0.11-0.14; CI 95.7-100.0; PI 109.3-112.7; PPeI 210.0-228.2; PPpI 190.9-215.0; HBaI 28.9-29.8.

Queen

de Andrade and Baroni Urbani (1999) - Head with disc as in the soldier, but the floor of the disc less concave anteriorly and flat to gently convex posteriorly. Frontal carinae superficially crenulated. Ocelli placed far from the vertexal margin.

Mesosoma. Pronotum as in the soldier. Mesonotum and scutellum at the same plane and slightly flat. Propodeum well differentiated in basal and declivous faces. Basal face converging and with two pairs of teeth, the first pair short, broad and almost round and the second one longer and slightly directed laterally. Declivous face as in the soldier.

Petiole slightly square, with the anterior face sloping and with the posterior one short and flat. Petiolar sides with a short, pointed tooth. Postpetiole as in the soldier, but with the tip of its spines more pointed.

Gaster oval, narrow anteriorly, broadening posteriorly. Anterolateral gastral lobes protruding and with a thin margin not reaching the stigma.

Hind femora without angle or denticle in the middle. Hind basitarsi as in the soldier.

Sculpture. Body integument as in the soldier, except for the mesonotum and scutellum with sparser foveae and for the upper mesopleurae densely foveolate.

Pilosity. As in the soldier, with the following differences: mesosoma and pedicel with the same rare, suberect, slightly clavate hairs as on the mandibles and legs; this same type of hairs surrounding the frontal carinae.

Colour. As in the soldier except for the center of the head disc light brown, and the dorsum of the pronotum with a yellow-orange triangle. Small specimens have the center of the disc completely black.

Measurements (in mm) and indices: TL 6.92-7.48 (dwarf specimen 5.84); HL 1.48-1.68 (dwarf specimen 1.24); HW 1.44-1.64 (dwarf specimen 1.28); EL 0.37-0.38 (dwarf specimen 0.34); PW 1.38-1.56 (dwarf specimen 1.20); PeW 0.57-0.60 (dwarf specimen 0.53); PpW 0.75-0.76 (dwarf specimen 0.63); HBaL 0.48-0.51 (dwarf specimen 0.47); HBaW 0.14-0.15 (dwarf specimen 0.12); CI 97.3-97.6 (dwarf specimen 103.2); PI 104.3-105.1 (dwarf specimen 106.7); PPeI 242.1-260.0 (dwarf specimen 226.4); PPpI 184.0-205.2 (dwarf specimen 190.5); HBaI 29.2-29.4 (dwarf specimen 25.5).

Male

de Andrade and Baroni Urbani (1999) - Head (eyes included, mandibles excluded) about 1/3 broader than long. Vertexal angles gently convex and without median angles. Ocelli protuberant. Vertex moderately convex. Frontal carinae simply marginate, diverging backwards and not reaching the posterior border of the eyes. Frons superficially concave medially. Clypeus convex. Mandibles short and laterally carinate. Scapes thick, twice as long as the first funicular joint; remaining funicular joints thickening from the base to the apex.

Mesosoma robust. Anterior pronotal border convex. Pronotal sides in dorsal view subparallel and slightly marginate in few specimens only. Mayrian furrows impressed; parapsidal furrows variably impressed. Propodeal sides converging posteriorly.

Petiole narrower than the postpetiole and with truncate and medially concave anterior face; petiolar sides convex anteriorly and converging posteriorly. Postpetiolar dorsum convex; postpetiolar sides subconvex, sometimes with a minute, round denticle.

Gaster almost as broad as the mesosoma.

Sculpture. Body shining, head subopaque. Head dorsum minutely punctate and irregularly foveolate rugose, the rugosities slightly transversal around the eyes. Ventral part of the head with the same type of sculpture as on the posterior part of the dorsum but with more irregular foveae and with transversal rugosities around the eyes. Pronotum superficially punctate and foveolate. Mesonotum and scutellum sparsely punctate and foveolate, the foveae very small and superficial. Basal face of the propodeum with dense, thick, longitudinal rugosities. Pleurae variably punctate-foveolate and with thin, longitudinal rugosities. Pedicel, gaster, coxae and femora with traces of superficial reticulation. Tibiae and tarsi punctate.

Pilosity. Body with long, erect, pointed hairs, denser on the head and on the mesosoma, rare on the first gastral tergite, appressed on the posterior border of the gastral tergites and absent on the tibiae and tarsi. Gaster, tibiae and tarsi with short, appressed hairs, denser on the tibiae and tarsi.

Colour. Head, mesosoma, pedicel and coxae black. Gaster brown. Femora lighter. Remaining parts of the legs yellowish.

Measurements (in mm) and indices: TL 5.20-5.80; HL 0.76-0.78; HW 0.96-1.02; EL 0.38-0.40; PW 1.00-1.04; PeW 0.36-0.39; PpW 0.43-0.44; HBaL 0.61; HBaW 0.08; CI 126.3-130.8; PI 92.3-102.0; PPeI 226.7-277.8, PPpI 227.3-241.8; HBaI 13.1.

Type Material

de Andrade and Baroni Urbani (1999):

Soldier. Type locality: Mato Grosso. Type material: holotype soldier labelled “Mato Grosso, Germain” in Museo Civico di Storia Naturale, Genoa (examined).

Cryptocerus denticulatus. Worker. Type locality: Salinas on the Rio Beni (Bolivia). Type material: 7 syntype workers 6 in MCSN, 1 in Musee d'Histoire Naturelle Genève) partly labelled “Bolivia, Rio Beni, Salinas, Balzan 1891”, examined.

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 684, Combination in Cephalotes, revived from synonymy)
  • Emery, C. 1894d. Studi sulle formiche della fauna neotropica. VI-XVI. Bull. Soc. Entomol. Ital. 26: 137-241 (page 205, pl. 3, figs. 15, 16 soldier described)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168 (page 98, queen described; page 94, combination in Paracryptocerus (Harnedia), senior synonym of denticulatus)
  • Kempf, W. W. 1958d. Synonymic note on ants of the genus Paracryptocerus Emery (Hymenoptera: Formicidae). Entomol. News 69: 108-110 (page 108, Junior synonym of conspersus)