Cephalotes alfaroi

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Cephalotes alfaroi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. alfaroi
Binomial name
Cephalotes alfaroi
(Emery, 1890)

Cephalotes alfaroi casent0040145 profile 1.jpg

Cephalotes alfaroi casent0040145 dorsal 1.jpg

Specimen labels

Specimens have been collected in various moist tropical forests. Little else is known about the biology of Cephalotes alfaroi.


A member of the atratus clade characterised by the crenulate frontal carinae bearing clavate hairs (less so than in the sister species Cephalotes serraticeps, and differing from its sister species serraticeps by the longitudinally rugulose head and for the narrower and not laterally compressed first tarsomeres of the mid and hind legs. All the alfaroi specimens we have seen (including the syntypes) differ from serraticeps by the minute longitudinal rugulation of the head and of the mesosoma (properly described by Kempf, 1951), by the less clavate hairs over the frontal carinae and by the shape of the tarsomeres of the fore, mid and hind legs, less compressed, narrower and longer than in serraticeps. (de Andrade and Baroni Urbani 1999)

Keys including this Species


Latitudinal Distribution Pattern

Latitudinal Range: 10.40126° to 8.6791°.

Tropical South

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality), Panama.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.


Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.



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.




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

  • alfaroi. Cryptocerus alfaroi Emery, 1890b: 76 (s.w.) COSTA RICA.
    • Type-material: 1 syntype soldier, 1 syntype worker.
    • Type-locality: Costa Rica: Alajuela, 1889 (A. Alfaro).
    • [Note: Emery, 1894k: 59, gives the type-locality as Jiménez.]
    • Type-depository: MSNG.
    • [Also described as new by Emery, 1894k: 59.]
    • Wheeler, G.C. & Wheeler, J. 1983: 607 (l.).
    • Combination in Cephalotes: Emery, 1914c: 39.
    • Junior synonym of serraticeps: Kempf, 1963c: 437; Kempf, 1972a: 76; Bolton, 1995b: 140.
    • Status as species: Dalla Torre, 1893: 140; Forel, 1899c: 48; Emery, 1914c: 39; Santschi, 1920f: 149 (in key); Emery, 1924d: 303; Kempf, 1951: 112 (redescription); De Andrade & Baroni Urbani, 1999: 129 (redescription).
    • Distribution: Costa Rica, Panama.

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



Kempf (1951) - Length 10.0 mm. Median head length 2.24 mm. Weber's length of thorax 3 . 1 7 mm. Similar to the major worker, from which it differs in the following features: Frontal carinae p artly semi-transparent, fuscous-ferruginous, converging in front, lateral border straight, preatly upturned. Each occipital angle with a pair of triangular spines, the anterior spine with a minute tooth arising from the base, projecting outward. Occiput continuous with vertex , not truncated, the pair of teeth on vertex obsolete. Integument subopaque, more sharply punctured and finely longitudinally rugulose caudad. Thorax subopaque, longitudinally areolate-rugose above and laterally. Scapular spines more slender, longer, acuminate, median teeth small, their bases transvese in the form of a crest. Spines of petiole more conspicuous. Sculpture of gaster sharper and coarser, distinctly longitudinally rugulose.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 8.40-11.46; HL 1.80-2.48; HW 2.20-2.88; EL 0.44-0.56; PW 1.76-2.70; PeW; PpW 0.60-0.80; HBaL 1.72-2.12; HBaW 0.35-0.47; CI 116.1-122.2; PI 106.7-125.0; PPeI 374.5-435.5; PPpI 280.0-360.0; HBaI 20.3-22.2.


Kempf (1951) - Length 13 mm. Median head length 2.97 mm. Weber's length of thorax 4.15 mm. Black; the following dark ferruginous: tip of last funicular segment, apices of last tarsal segments, claws.

Head subfulgid, subquadrate, microscopically punctate, coarsely and sparsely foveolate. Mandibles reticulate-rugose, with a distinct apical and preapical tooth. Clypeur and frontal area vestigially set off. Frontal carinae crenulated, their sides moderately arcuate and slightly upturned. Vertex with a transversely located pair of blunt swellings. Occiput subtruncate mesad. Occipital angles with a rather large and obtuse posterior tooth, the anterior tooth scarcely distinct from the crenulated border of the frontal carinae. In lateral view three minute denticules project ventrad from the frontal carinae, in front of the eye. Eyes beneath the antennal scrobe. Maxillary palpi 5-segmented. A small but distinct tooth projecting from the sides of the head, somewhat above and behind the eyes. Scape incrassated distad, attenuate and subcylindrical proximad.

Thorax subopaque. Shoulders obtusely angulate. Dorsal face of pronotum inclined cephalad, with two stout, rather acute median spines and a lateral, stout, more or less apically truncate scapular spine on each side, above and behind the shoulder. A minute tooth projecting distad from the anterior side of the scapular spine. Promesonotal suture distinct. Mesonotum moderately inclined caudad, flat, marginate laterad, its posterior corners marked by somewhat raised, blunt swellings. Mesoepinotal suture distinctly impressed. Basal face of epinotum somewhat inclined cephalad; about as long as wide, its sides immarginate, subequal in length to the declivous face. Lower mesopleura with an anterior tooth. Epinotal spines longer than basal face, divergent, somewhat upturned, subacuminate. Integument microscopically and densely punctate, sparsely foveolate. Middle portion of femora moderately incrassate, the upper face strongly marginate on the distal end. Tibiae prismatic. Middle and hind basi tarsus compressed and greatly flattened.

Petiole subopaque; subquadrate from above, its sides subparallel. Anterior face obliquely truncate. Anterior corner of dorsal face with a laterally projecting minute tooth. Integument finely and densely punctate, and sparsely foveolate. Postpetiole wider than long, with a pair of conspicuous recurved teeth above, on the anterior border. Ventral face with a distinctly ventrally projecting lobe. Sculpture as on petiolc. Densely foveolate-rugose.

Gaster subfulgid. First tergite and firts sternite microscopically and very shallowly punctate, almost smooth, fulgid, except the narrow posterior margin, which, as also the exposed portion of the remaining tergites and sternites, are more sharply punctured and transversely rugulose.

Most of the foveolae contain a thin, short, decumbent seta. Margin of frontal carinae with a row of somewhat clubbed setae within the crenulations, along their entire length. Mandibles, lowe rsurface of head, spines of thorax, postpetiole appendages and gaster above and below, with sparse, erect setae.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 12.62-13.02; HL 2.92-3.04; HW 3.52-3.60; EL 0.68; PW 3.20-3.32; PeW 0.74-0.84; PpW 0.87-0.92; HBaL 2.04-2.08; HBaW 0.52; CI 118.4-120.5; PI 106.0-112.5; PPeI 381.0-448.6; PPpI 347.8-381.6; HBaI 25.0-25.5.

Type Material

de Andrade and Baroni Urbani (1999) - Worker and soldier. Type locality: Alajuela (Costa Rica). Type material: two workers labelled "Alajuela, Alfaro" in Museo Civico di Storia Naturale, Genoa; one worker and one soldier with syntype label only, in Musee d'Histoire Naturelle Genève, examined.


References based on Global Ant Biodiversity Informatics

  • Emery C. 1890. Studii sulle formiche della fauna neotropica. Bull. Soc. Entomol. Ital. 22: 38-8
  • Emery C. 1894. Estudios sobre las hormigas de Costa Rica. Anales del Museo Nacional de Costa Rica 1888-1889: 45-64.
  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • INBio Collection (via Gbif)
  • Kempf W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Revista de Entomologia (Rio de Janeiro) 22:1-244
  • Kempf W. W. 1959. Insecta Amapaensia. - Hymenoptera: Formicidae. Studia Entomologica (n.s.)2: 209-218.
  • Longino J. T., J. Coddington, and R. K. Colwell. 2002. The ant fauna of a tropical rain forest: estimating species richness three different ways. Ecology 83: 689-702.
  • 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