Cephalotes manni

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

Cephalotes manni P casent0627955.jpg

Cephalotes manni D casent0627955.jpg

Specimen Label

Cephalotes manni was collected from a dead vine in a dense second growth forest with few larger trees.

Identification

A member of the basalis clade characterised: in the worker, by the vertexal angles broad and almost round, by the mid and hind basitarsi narrow and not compressed at the base and by three pairs of pronotal and three pairs of propodcal teeth; in the soldier, by the vertexal margin concave and by the frontal carinae anteriorly with a marginal row of clubbed hairs. C. manni is the smallest species of the basalis clade.

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

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

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.

  • manni. Paracryptocerus (Paracryptocerus) manni Kempf, 1951: 228, fig. 127, 128 (s.w.) BRAZIL. Combination in Zacryptocerus: Brandão, 1991: 387; in Cephalotes: De Andrade & Baroni Urbani, 1999: 237.

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

Description

Worker

Kempf (1951) - 4.0 mm. Median head length 1.05 mm; Weber's length of thorax 1.22 mm. Black; the following ferruginous: tip of mandibles, frontal carinae, tip of scape, first funicular segment, tip of femora, tibiae, fore tarsi, 2-4 middle and hind tarsi, anterolateral crest of gaster. Tip of thoracic and peduncular spines rufous brown.

Head subopaque. Mandibles finely reticulate-punctate and rugulose. Frontal carinae without crenulate border, beset with projecting setulae on the anterior half, the setulae arising from above. Posterior portion of frontal carinae slightly diverging caudad, and strongly sinuate, emarginate in front of, convex and upturned above, the eyes, a few erect setae above the eyes. Eyes prominent, their maximum diameter longer than 1/3 of median head length. Occipital corners obliquely subtruncate, the occipital border evenly concave. Cheeks strongly marginate beneath, very densely scaled. Upper surface of head scarcely convex, very finely and densely reticulate-punctate, sparsely covered with simple, appressed, flattened, silvery hairs, which became canaliculate and situated in more or less excavated grooves in front of the occipital border.

Thorax subopaque. Pronotum with a tridenticulate crest on each side. Mesonotum with an acute lateral tooth. Promesonotal and mesoepinotal sutures obsolete. Basal face of epinotum with a pair of small teeth near the anterior corner and a third tooth on the posterior corner, the posterior border of which is prolonged behind in a crest, delimiting the declivous face laterad and behind, as in simillimus. Upper surface of thorax finely reticulate-punctate, with scattered longitudinal grooves, each containing a decumbent, silvery canaliculate scale. Laterotergite of pronotum longitudinally striated. Sides of thorax finely reticulate with sparse, simple, appressed setae. Femora incrassated, somewhat compressed, angulate above at the half. Basitarsi slender, not conspicuously flattened and broadened at base.

Petiole subopaque, the anterior face truncate, with a strong lateral somewhat recurved spine. Postpetiole as long as petiole, with a slightly shorter, lateral spine, curved forward at base, slightly recurved at apex. Sculpture of both peduncular segments as on upper surface of thorax.

Gaster subopaque, oval. Greatly emarginate mesad in front, distinctly crested antero-laterad, the crest extending hackward over more than half of the sides of the first gastral tergite, fading out shortly in front of the apical third. Upper surface of gaster finely reticulate-punctate, rather densely covered with mostly simple, silvery appressed scales, lying in shallow grooves. Erect pile confined to tergites 2-4 and the apical border of sternite I and the following sternites.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.04-5.06; HL 1.00-1.24; HW 1.24-1.58; EL 0.40-0.42; PW 1.00-1.32; PeW 0.68-0.85; PpW 0.60-0.80; HBaL 0.32-0.41; HBaW 0.08-0.12; CI 121.1-127.4; PI 119.7-124.0; PPeI 144.4-155.3; PPpI 162.5-168.7; HBaI 23.5-29.3.

Soldier

Kempf (1951) - 6 mm. Median head length 1.41 mm. Weber's length of thorax 1 .66 mm. Black; the following ferruginous: tip of mandibles, outer portion of frontal carinae, tip of femora, tibiae and tarsi. The first funicular segment and the tip of the last segment lighter.

Head subfulgid; subquadrate, anterior corners greatly rounded, posterior corners subrectangular. Mandibles angular, reticulate rugose. Frontal carinae extending to the occipital corner, upturned, crenulate, with a rim of projecting clubbed setulae. Upper surface of head slightly convex discad. Occipital border straight, crested, with a median depression. Occiput not truncate beneath the crest, confluent with the lower surface of the head. Eyes elongate, ovoid. A distinct carina extended from beneath the eye to the occipital corner. Upper surface of head finely reticulate, coarsely and rather densely foveolate, with a simple, decumbent, glittering hair in each foveola. Lower surface of head with the microsculpture partly obsolete, more fulgid, reticulate-foveolate.

Thorax subfulgid above. Propotum greatly expanded; anterior border arcuate, shoulders obsolete, not set off, the sides 'greatly expanded, anterior corners acutely angulate, sides straight, converging towards the mesonotum, the posterior corners rounded, and slightly depressed. Pronotum with a transverse crest, flat, continuous with the mesonotum, in the same plane. Promesonotal suture vestigial. Sides of mesonotum with an obliquely truncate, lateral lobe, the posterior corner of which is slightly upturned. Mesoepinotal suture impressed laterad, obsolete discad. Basal face of epinotum with a basal rectangular tooth, and, following, a larger similar plate-like tooth, and a broad, more or less rounded lobe on the posterior corner, the posterior, (internal), border of which is continuous with the emarginate posterior border of the basal face. Upper surface of thorax sculptured as on head, foveolae more crowded. Laterotergite vestigially longitudinally striated. Sides and declivous face subopaque, finely reticulate-punctate. Femora incrassated, somewhat compressed, indistinctly angulate above at the half.

Petiole and postpetiole as in worker, the spines shorter and stouter, and somewhat blunt at apex.

Gaster subopaque, elongate, broadest behind the half. First gastral tergite conspicuously emarginate anteriorly mesad, submarginate, nor crested, antero-Iaterad. Upper surface finely reticulate-punctate, with scattered, minute silvery, simple appressed hairs. Erect pilosity as in worker.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 6.00; HL 1.40; HW 1.68; EL 0.42; PW 1.64; PeW 0.83; PpW 0.81; HBaL 0.36; HBaW 0.12; CI 120.0; PI 102.4; PPeI 197.6; PPpI 202.5; HBaI 23.5.

Type Material

de Andrade and Baroni Urbani (1999) - Worker, soldier. Type locality: Cachoeira Breu (Para, Brazil). Type material: holotype and 1 paratype workers labelled "Est. Para, Cachoeira Breu, X.1 928, Sampaio" in Museu de Zoologia da Universidade de Sao Paulo, examined.

References

  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 387, 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 237, Combination in Cephalotes)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 228, fig. 127, 128 soldier, worker described)