Cephalotes borgmeieri

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Cephalotes borgmeieri
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. borgmeieri
Binomial name
Cephalotes borgmeieri
(Kempf, 1951)

Cephalotes borgmeieri casent0173664 profile 1.jpg

Cephalotes borgmeieri casent0173664 dorsal 1.jpg

Specimen labels

Specimens of Cephalotes borgmeieri have been collected in dry chaco transistional habitat in Paraguay. Little else is known about the biology of Cephalotes borgmeieri.

Identification

A member of the depressus clade differing from its next ingroup species, Cephalotes betoi, in the worker and in the soldier by the infuscate frontal carinae and by the pronotal lamellae truncate, and in the worker, soldier and gyne by the larger HBaL.

Keys including this Species

Distribution

Brazil, Argentina (Misiones) and Paraguay.

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (type locality), Brazil, Ecuador, Paraguay.

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.

  • borgmeieri. Paracryptocerus (Paracryptocerus) borgmeieri Kempf, 1951: 211, fig. 147 (w.q.m.) ARGENTINA. De Andrade & Baroni Urbani, 1999: 339 (s.). Combination in Zacryptocerus: Brandão, 1991: 385; in Cephalotes: Baroni Urbani, 1998: 323. See also: Kempf, 1969: 285.

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

Description

Worker

Length 5.7 mm. Median head length 1.34 mm; Weber's length of thorax 1.58 mm. Fuscous reddish-brown; appendages more or less rufous-brown; gaster almost black.

Head subopaque, greatly depressed; subquadrate. Interocular distance exceeding maximum length of head. Mandibles very finely reticulate-punctate, vestigially rugulose. Frontal carinae rounded in front, slightly sinuate and subparallel at the sides, somewhat upturned above the eye, reaching the occipital corner. Sides vestigially crenulate, the projecting setulae in the notches minute to obsolete. Upper surface of head very little convex, very finely reticulate-punctate, somewhat more coarsely reticulate-rugulose, rather densely covered with large, oval, appressed, canaliculate, pale yellowish, glittering, scale-like hairs. Vertical teeth vestigial. Occipital border emarginate, occipital corners obliquely truncate, with an outer blunt and an inner more acute denticule. Cheeks strongly marginate beneath, very densely covered with minute scales as on upper surface. Lower surface with distant, longitudinal rugulae, and sparse, scattered, simple, appressed hairs.

Thorax subopaque; much broader across the pronotum than long. Upper surface of thorax including the declivous face of epinotum continuously and cospicuously convex in profile. Sculptured and scaled as the upper surface of head. Anterior border arcuate, shoulders angulate, separate from the broad, long, lateral lamellae of the pronotum, the anterior border of which is arcuate, the outer border sinuate, the posterior border concave. Promesonotal suture obsolete. Mesonotum with a blunt lateral spine. mesoepinotal suture obsolete. Sides of epinotum with a long, plate-like depressed spine in front, and a shorter, triangular, plate-like tooth behind, close to the posterior corner, the posterior border of which forming a crest, delimiting the declivity behind. Sides of thorax finely reticulate-punctate, distinctly longitudinally rugose, with sparser, canaliculate scales, longer than those on the upper face. Mid and hind femora distinctly angulate above. Mid and hind basitarsi flattened and broadened proximad, attenuate distad.

Petiole subopaque; anterior border, including the long recurved spines, evenly curved. Postpetiole subopaque, narrower and shorter than petiole, lateral spines slightly curved forward at base, vestigially recurved at apex. Sculpture and scales as on thorax.

Gaster subopaque, cordiform, about as broad as long. First gastral tergite moderately emarginate anteriorly mesad, narrowly crested antero-Iaterad, sculpture and scales as on thorax."

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 3.96-5.96; HL 0.92-1.44; HW 1.28-2.00; EL 0.32-0.48; PW 1.28-2.04; PeW 0.90-1.40; PpW 0.72-1.08; HBaL 0.32-0.48; HBaW 0.12-0.22; CI 131.2-141.6; PI 93.3-100.0; PPeI 140.6-147.8; PPpI 1.66.6-188.9; HBaI 37.5- 45.8.

Soldier

de Andrade and Baroni Urbani (1999) - Head subquadrate, with an incomplete disc. Head dorsum convex. Vertexal corners with two pairs of obtuse teeth or almost truncate. Posterior border of the disc with a pair of developed median teeth superficially connected each other by a median carina, the carina superficially continuing laterally into the frontal carinae. Anterior half of the frontal carinae with broad, crenulate border; posterior half of the frontal carinae converging before the eyes, ending on their posterior border and strongly marginate above them. Mandibles broad, their sides with an impressed, round, carinate protuberance. Eyes gently convex.

Mesosoma broad anteriorly, narrowing posteriorly. Scapular angles short but visible in dorsal view. Pronotal sides with a pair of developed, broad, rectangular lamellae; their sides converging posteriorly. Pronotal carina well marked, raised, superficially crenulate and interrupted medially by an impression. Promesonotal suture impressed. Mesonotal sides with a pair of broad, obtuse teeth. Propodeal suture deeply impressed. Propodeum with poorly differentiated basal and declivous faces. Basal face broadening posteriorly and ending in a pair of broad, thick, obtuse or round spines; its dorsum gently convex in the middle and on the same plane as the declivous face. Declivous face straight in the middle; its sides converging posteriorly and bearing medially a pair of triangular, lamellaceous teeth.

Petiolar sloping anteriorly; its anterior border medially concave. Petiolar sides gently curved posteriorly and with a broad, triangular, pointed spine with curved apex. Postpetiole, in lateral view, slightly convex, the middle of its dorsum flat; postpetiolar spines thick, arising from the anterior face of the postpetiole and curved backwards.

Gaster suboval, with anterior expansions. Anterolateral border of the first gastral sternites with a thick margin reaching the stigma.

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

Sculpture. Head reticulate-punctate and covered by small foveae as broad as their interspaces, diminishing in size anteriorly. Vertexal corners, ventral face of the head, sides of the pronotum and of the mesonotum with foveae larger and deeper than those on the posterior part of the head. Middle of the pronotum and of the mesonotum with foveae denser and smaller than on their sides. Propodeum, ventral part of the meso- and metapleurae, petiole, postpetiole, distal part of the extensor face of the femora and extensor face of the tibiae with dense, oval foveae. Remaining pleural parts reticulate and with thin, longitudinal rugosities. Centre of the declivous face of the propodeum reticulate only. First gastral tergite reticulate and with dense piligerous foveae on the anterior fourth. Sternite reticulate and with sparse superficial, small foveae; centre of the first gastral sternite slightly shining.

Pilosity. Each fovea bearing an appressed hair of size proportional to the one of the foveae. Sides of the head, of the mesosoma, mandibles, legs, and gaster with sparse, short, clavate hairs. Caudal portion of the sternites with sparse, long, suberect, truncate hairs.

Colour. Dark ferruginous black. Frontal carinae and legs lighter.

Measurements (in mm) and indices: TL 7.12-8.20; HL 1.72-1.96; HW 2.32-2.52; EL 0.52-0.54; PW 2.24-2.48; PeW 1.44-1.52; PpW 1.20-1.28; HBaL 0.52-0.56; HBaW 0.24-0.27; CI 128.6-134.9; PI 100.0-103.6; PPeI 155.5-163.1; PPpI 186.7-200.0; HBaI 43.6-48.2.

Queen

Kempf (1969) - Total length 9.6 mm; head length 2.13 mm; head width (eyes included) 2.50 mm; scape length 0.70 mm; maximum diameter of eyes 0.51 mm; thorax length 2.81 mm; maximum width of thorax 2.50 mm; petiole width 0.97 mm; postpetiole width 1.08 mm. Very close to depressus with the following differences: frontal carinae concolorous with rest of head; occipital corners more distinctly obliquely truncate and bidentate; occiput truncate in the middle, indistinctly marginate above the truncation, bearing on vertex, just behind the ocelli a pair of small to vestigial teeth; scapular spine stronger, more protruding, pointing obliquely laterad and cephalad; laterotergite of pronotum mostly without impressed foveolae and appressed scalelike hairs, except on anterior margin; petiole in dorsal view broader, its sides obliquely diverging caudad, the lateral spines pointing obliquely laterad and caudad; postpetiole with longer and somewhat more delicate spines."

Wings. Fore wings with R+Sc superficially connected to a marked pterostigma. cu-a superficially connected with A. 2r marked, Rsf5 connected to R1. Distal parts of A, CuAl and Mf4 slightly marked. Hind wings with R, M+ CuA and M marked; 1A,CuA, M and distal part of A vestigial.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 9.72-9.90; HL 1.80-1.84; HW 2.12-2.16; EL 0.48; PW 2.10-2.24; PeW 0.88-0.98; PpW 0.96-1.08; HBaL 0.65-0.67; HBaW 0.28-0.29; CI 117.4-117.8; PI 94.6-102.8; PPeI 228.6-238.6; PPpI 207.4-218.7; HBaI 41.8-44.6.

Male

de Andrade and Baroni Urbani (1999) - Head about 1/3 broader than long (eyes included, mandibles excluded); vertexal margin straight, faintly carinate and ending in an obtuse or pointed corner. Ocelli protuberant from the little convex vertex. Eyes broadly convex and placed in the middle of the sides of the head. Frontal carinae diverging backwards and not reaching the posterior border of the eyes. Frons flat and separate from the clypeus by a superficial furrow. Clypeus convex, its posterior half higher than the anterior one, almost truncate. Mandibles slender, laterally carinate and with a distinct apical tooth. 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 broadening backwards, superficially carinate on the sides and with a slightly marked scapular angle; mesonotum convex; median Mayrian carina and parapsidal furrows weakly impressed; scutellum convex, its sides converging posteriorly; propodeum with poorly differentiate basal and declivous faces; basal face convex, its sides converging posteriorly towards the declivous face, the latter with lateral and median carinae.

Petiole slightly narrower than the postpetiole and with a deeply concave anterior border; petiolar sides convex medially. Postpetiole little convex dorsally; postpetiolar sides convex anteriorly and converging posteriorly.

Gaster almost as broad as the mesosoma.

Wings as in the gyne.

Sculpture. Body deeply reticulate-punctate. Head dorsum, meso- and metapleurae with irregular and variably impressed rugulae, more regular on the p eriocular area, on the basal face of the propodeum and on the peduncular sides. Sparse, shallow foveae on the head and on the mesosoma. First gastral segment and legs reticulate-punctate; on the remaining gastral segments the same sculpture but less impressed and the tegument is slightly shining.

Pilosity. Head and mesosoma covered by dense, long, suberect hairs, sparser and subdecumbent on the pedicel, on the sternites and on the legs, rare on the tergites. Funiculi densely covered by thin, short, decumbent hairs; similar but thinner, sparser and slightly longer hairs on the legs and on the gaster.

Colour. Black with scapes and first funicular joints lighter; remaining funicular joints ferruginous. Coxae, trochanters and proximal half of the femora light brown; remaining legs parts yellow. Wings light brown and infuscate.

Measurements (in mm) and indices: TL 6.14-6.76; HL 0.92; HW 1.28; EL 0.44-0.46; PW 1.24-1.32; PeW 0.64-0.65; PpW 0.68-0.69; HBaL 0.56-0.60; HBaW 0.12; CI 139.1; PI 97.0-103.2; PPeI 193.7-203.1; PPpI 1 82.3-191.3; HBaI 20.0-21.4.

Type Material

Worker. Type locality: Iguazu (Misiones, Argentina). Type material: holotype and 3 paratype workers at the Instituto Miguel Lillo, Tucuman (Argentina) (Kempf, 1951), not available for the present study, one paratype worker in Museu de Zoologia da Universidade de Sao Paulo (examined).

References

  • Baroni Urbani, C. 1998b. The number of castes in ants, where major is smaller than minor and queens wear the shield of the soldiers. Insectes Soc. 45: 315-333 (page 323, Combination in Cephalotes)
  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 385, Combination in Zacryptocerus)
  • 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 339, soldier described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 211, fig. 147 worker, queen, male described)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168.
  • Kempf, W. W. 1969. Miscellaneous studies on Neotropical ants. V. (Hymenoptera, Formicidae). Stud. Entomol. 12: 273-296 (page 285, see also)