Cephalotes ramiphilus

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Cephalotes ramiphilus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species group: basalis
Species: C. ramiphilus
Binomial name
Cephalotes ramiphilus
(Forel, 1904)

Cephalotes ramiphilus casent0909260 p 1 high.jpg

Cephalotes ramiphilus casent0909260 d 1 high.jpg

Specimen Labels

Nothing is known about the biology of Cephalotes ramiphilus.


A member of the basalis clade differing from its sister species Cephalotes cordiae, by the propodeum with two or three pairs of teeth (instead of one) in the worker, and simply convex (instead of with one diverging spine), in the soldier, and, in the gyne, by the body less shining and with more impressed foveae. C. ramiphilus and cordiae are the two species in the basalis clade sharing round vertexal angles and high HBaI. Both species are represented by few specimens in the collections and are restricted to northern South America, with ramiphilus occurring more in the north and cordiae more in the south. The two species occur parapatrically in the NW part of Brazil. (de Andrade and Baroni Urbani 1999)

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: -0.631944444° to -3.882°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Colombia, Ecuador, Peru.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb


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.


Males have not been collected.


The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • ramiphilus. Cryptocerus complanatus r. ramiphilus Forel, 1904e: 678 (s.w.) BRAZIL. De Andrade & Baroni Urbani, 1999: 251 (q.). Combination in Cryptocerus (Paracryptocerus): Emery, 1924d: 307; in Paracryptocerus: Kempf, 1951: 196; in Zacryptocerus: Brandão, 1991: 388; in Cephalotes: De Andrade & Baroni Urbani, 1999: 247. Raised to species: Kempf, 1967e: 362.

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



Kempf (1951) - Length 5.4 mm. Median head length 1.27 mm; Weber's length of thorax 1.51 mm. Black; the following fuscous ferruginous: apex of mandibles, apical three tarsal segments. Tip of last funicular segment yellowish. Head subopaque, subquadrate. Mandibles finely reticulate-punctate and rugulose. Sides of head very little sinuate, not upturned above the eye. Frontal carinae prolonged behind the scrobe as a distinct carina, not reaching the occipital corner. Occipital corners rounded, occipital border straight, scarcely emarginate mesad, sharply carinate laterad. Upper surface of head moderately convex, finely reticulate-punctate, sparsely covered with very shallow elongate grooves, each containing a large, usually canaliculate, appressed, silvery, scale-like hair. Cheeks strongly carinate below, densely covered with silvery, appressed scales. Lower surface of head more fulgid, scales sparser.

Thorax subopaque. Sides of lateral pronotal plates more or less subparallel, anterior and posterior corners rounded. Promesonotal suture obsolete. Mesonotum with a strong lateral spine. Mesoepinotal suture obsolete. Basal face of epinotum with a broad, plate-like, triangular tooth on each side, having on its anterior border a minute, rather blunt, denticule, and a posterior, rather short, slender, acuminate spine, projecting obliquely backwards, about as long as half the length of the basal face. Pronotum convex in profile. Mesoepinotum flat longitudinally, slightly convex transversely. Posterior border of basal face of epinotum submarginate. Sides of declivous face carinate. Dorsum of thorax finely reticulate-punctate, with sparse, squamiferous foveolae, scales conspicuous, appressed, silvery and canaliculate. Sides of thorax and declivous face very finely and distantly longitudinally striated, and very finely reticulate. Tibiae prismatic. Petiole and postpetiole subopaque, petiolar spines upturned and somewhat recurved. Both segments without a dorsal median longitudinal carinule.

Gaster subopaque, elongate, cordiform. First gastral tergite conspicuously emarginate anteriorly mead, broadly crested antero-laterad, sculptured as upper surface of the thorax, foveolae vestigial, scales more slender, and simple. Erect hair on the following tergites and the sternites.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 5.16-6.68; HL 1.24-1.56; HW 1.56-1.92; EL 0.40-0.48; PW 1.38-1.76; PeW 1.00-1.40; PpW 0.88-1.20; HBaL 0.51-0.52; HBaW 0.24-0.27; CI 116.2-125.8; PI 109.1-113.0; PPeI 125.7-147.1; PPpI 146.6-165.9; HBaI 47.0-51.9.


Kempf (1951) - Length 7 mm. Median head length 1.87 mm; Weber's length of thorax 2.09 mm. Black.

Head fulgid, subquadrate; rounded anteriorly and posteriorly. Mandibles finely reticulate-rugose. Frontal carinae scarcely raised, continued behind the scrobes as a distinct carina, above the eyes, fading out before reaching the occipital corner. Upper surface of head moderately convex, vertex without teeth. Occiput distinctly truncate, submarginate above mesad, marginate laterad. Checks submarginate beneath, the lower border continuing behind below the eyes as a distinct carina, reaching the occipital corner. Upper surface of head smooth, sparsely and rather finely foveolate, the foveolae containing a minute yet visible hair. Lower surface of head more sparsely foveolate, the foveolae with a more conspicuous hair.

Thorax subfulgid. Pronotum expanded laterad, the anterior border conspicuously arcuate, the anterior corner angulate, the sides parallel and crested onto the transverse pronotal crest, then abruptly bent mesad, towards the mesonotum. Transverse pronotal crest distinct laterad, somewhat obsolescent mesally. Promesonotal suture vestigial. Mesonotum with a strong apically rounded lateral tooth. Mesoepinotal suture impressed, scarcely arcuate. Basal face of epinotum without a lateral spine, sides arcuate and crested, the posterior corner with a small, not divergent, tooth, the posterior border sharply marginate. Declivous face smooth, slightly excavate, superficially and very finely reticulate. Promesonotum finely punctate, basal face of epinotum and sides of thorax very finely, shallowly reticulate-punctate. Dorsum of thorax, laterotergite of pronotum sparsely foveolate, with rather large, golden, always visible scales within the foveolae. Scales very conspicuous on basal face of epinotum. Upper face of tibiae and apical half of upper face of femora rather densely scaled.

Petiole with smooth anterior truncate face, marginate above. The upper face scaled and foveolate. The spines not greatly upturned, stouter than in worker. Postpetiole similarly sculptured, the spines not upturned.

Gaster subopaque, finely reticulate-punctate, elongate, subcordiform. The first gastral tergite moderately emarginate anteriorly mesad, narrowly crested laterad, with scattered, minute, glistening, appressed setulae. Sternites subfulgid, shallowly and very finely reticulate, more sparsely scaled. Erect, sparse setae on the apical third of the gaster.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 7.00-8.08; HL 1.76-2.00; HW 2.08-2.28; EL 0.48-0.52; PW 1.88-2.24; PeW 1.08-1.44; PpW 1.10-1.32; HBaL 0.52-0.60; HBaW 0.28-0.32; CI 114.0-118.1; PI 101.8-110.6; PPeI 147.2-174.1; PPpI 160.6-170.9; HBaI 51.7-53.8.


de Andrade and Baroni Urbani (1999) - Head convex, without disc. Frontal carinae converging anteriorly and straight posteriorly up to the end of the eyes. Vertexal angles rounded and marginate. Vertex marked by a faint, straight carina. Mandibles with a lateral carina.

Mesosoma. Humeral angles broad and obtuse. Pronotal carina poorly marked on the middle and faintly on the sides. Mesonotum and scutellum flat in side view. Lower mesopleurae with a denticle. Sides of the basal face of the propodeum convex anteriorly, converging posteriorly and with a broad, pointed tooth; declivous face converging posteriorly.

Petiole distinctly differentiated in anterior and posterior faces; anterior face oblique; the posterior face declivous posteriorly. Petiolar sides with a pair of pointed spines directed backwards. Postpetiole broadly convex, with the spines arising from its anterior border and directed laterally.

Gaster marginate anteriorly.

Legs. Fore coxae tumuliform anteriorly. Mid and hind femora marked by an angle. Mid and hind basitarsi flat and broad at the base.

Sculpture. Head minutely reticulate-punctate and covered by small foveae with the interspace between them larger than their maximum diameter. Frontal carinae with shallower foveae than those on the head. Vertexal area, ventral part of the head, mesosoma and pedicel with round foveae larger and deeper than those on the head dorsum, sparser on the ventral face of the head and on the occipital area behind the head dorsum, and contiguous on the basal face of the propodeum and on the dorsal part of the mesopleurae. Declivous face of the propodeum, posterior half of the ventral part of the mesopleura, metapleurae, legs and gaster reticulate-punctate and slightly shining, with faint longitudinal rugulations on metapleurae.

Pilosity. Each fovea bearing a thin, appressed hair; mandibles, and legs with rare, slightly clavate, suberect hairs. Second and remaining tergites and sternites with two types of hairs: rare, long pointed hairs, and thick, erect, truncated hairs, shorter than the pointed one.

Colour. Black. Last funicular joints ferruginous.

Measurements (in mm) and indices (based on one specimen from Leticia, Colombia): TL 9.20; HL 1.84; HW 2.00; EL 0.52; PW 1.96; PeW 1.10; PpW 1.22; HBaL 0.64; HBaW 0.29; CI 108.7; PI 102.0; PPeI 178.2; PPpI 160.6; HBaI 45.3.

Type Material

de Andrade and Baroni Urbani (1999) - Worker and soldier. Type material: lectotype worker in Musee d'Histoire Naturelle Genève (Kempf, 1951: 198); a specimen detached in the ramiphilus drawer in the MHNG without corresponding pin and labels of any kind could represent the lectotype designated by Kempf (1951: 158) of which we find no traces either in MHNG or in Museu de Zoologia da Universidade de Sao Paulo. This specimen had been re-mounted and labelled "C. ramiphilus (Forel), lectotype of Kempf 1951?". Syntypes examined: 1 worker and 1 soldier labelled "Born Fim Jurua, Nov. 1900, in perforated twigs of Platymiscium ulei Harms. Cr. complanatus Guerin r. ramiphilus Forel, type, Amazonas (Ule)" (MHNG).


  • 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 251, queen described, page 247, 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 388, Combination in Zacryptocerus)
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 307, Combination in Cryptocerus (Paracryptocerus))
  • Forel, A. 1904f. In und mit Pflanzen lebende Ameisen aus dem Amazonas-Gebiet und aus Peru, gesammelt von Herrn E. Ule. Zool. Jahrb. Abt. Syst. Geogr. Biol. Tiere 20: 677-707 (page 678, soldier, worker described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 196, Combination in Paracryptocerus)
  • Kempf, W. W. 1967e. A new revisionary note on the genus Paracryptocerus Emery (Hym. Formicidae). Stud. Entomol. 10: 361-368 (page 362, Raised to species)
  • Oliveira, A.M., Powell, S., Feitosa, R.M. 2021. A taxonomic study of the Brazilian turtle ants (Formicidae: Myrmicinae: Cephalotes). Revista Brasileira de Entomologia 65, e20210028 (doi:10.1590/1806-9665-rbent-2021-0028).

References based on Global Ant Biodiversity Informatics

  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • 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