Cephalotes porrasi

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Cephalotes porrasi
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. porrasi
Binomial name
Cephalotes porrasi
(Wheeler, W.M., 1942)

Cephalotes porrasi P casent0613103.jpg

Cephalotes porrasi D casent0613103.jpg

Specimen Label

Cephalotes porrasi has been collected in a variety of wet forests types and in acacia found along water courses. They can be collected from ground level as strays on vegetation.

Identification

A member of the pallens clade characterised by the following apomorphies: worker with the membranaceous expansions of the propodeum with two or three teeth, with the hind femora narrowly crested or carinate and with HBaI ≤ 34, soldier and gyne with thick, brush-shaped hairs on the head. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Belize, Colombia, Costa Rica, Ecuador, Guatemala, Mexico, Nicaragua, Panama (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

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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.

Morphology

Wheeler and Holldobler (1985) investigated how Cepholates workers might collect or accumulate debri on their head disks. Such debri can be used as camouflage for individuals that are using their head to block the nest entrance, much like Basicerotini and Stegomyrmicini ant species affix dirt their bodies. They discovered Cephalotes porrasi do in fact have encrusted material on their head disks. This varied from slight to extremely built-up material. Unexpectedly these covering materials appeared to be produced by the ants, rather than an accumulation of material that was affixed and somehow binded to the head disk. The presence of many pores, which are presumably attached to glands, are the likely source of secreted fibrous and filmy substances that were detected.

They also discovered: "Z. pallens porrasi (=C. porrasi) (Figs. 7-9). The two soldiers shown in Figs. 7-9 were collected from the same colony. The soldier is characterized by large brush setae on the cephalic disc (Fig. 7). Similar views of the two soldiers, one clean and one dirty, are shown in Fig. 8. In the soldier that appeared clean, the brush setae were free of accumulated material, but the surface seemed to be obscured by a thick encrusting material (Figs. 7, 8a). The second soldier had such a thick accumulation that the large brush setae were almost completely buried (Figs. 8b, 9a). The material on the head of the dirty soldier appeared fibrous (Fig. 9b), much like the material seen on the head of Z. varians (Cephalotes varians)(Fig. 3a)."

Castes

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • porrasi. Cryptocerus (Cyathocephalus) pallens var. porrasi Wheeler, W.M. 1942: 210, pl. 52 (s.w.q.m.) PANAMA. Combination in Cephalotes: De Andrade & Baroni Urbani, 1999: 486. Junior synonym of pallens: Kempf, 1958a: 151. Revived from synonymy and raised to species: De Andrade & Baroni Urbani, 1999: 486.

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) - Similar to the other species of the group from which it differs for one or more of the following characters. Head broader than long. Frontal carinae with minutely crenulate border. Membranaceous expansions of the vertexal angles narrow. Pronotum with a pair of membranaceous expansions continuous or superficially incised. Mesonotum with a pair of triangular, semi-membranaceous teeth and, in some specimens, an additional pair of minute denticles. Propodeal sides with a pair of membranaceous expansions bi- or tri-toothed. Anterior border of the petiole with a pair of salient swellings. Petiolar sides with a pair of pointed spines as long as or slightly shorter than their maximum length. Postpetiolar sides with a pair of pointed spines directed forwards. Gaster suboval and with a pair of anterolateral membranaceous expansions surpassing the stigma posteriorly and continuing until the posterior border of the first tergite as a superficial margin. Hind and mid femora angulate; their distal part with a dorsal, longitudinal carina less impressed on the mid femora; few specimens with a narrow crest on the hind femora.

Sculpture. Head dorsum and mesosoma minutely punctate, reticulate and with superficial, dense foveae, smaller behind the clypeus, sparser, shallower and less regular on the frontal carinae. Frontal carinae with additional, oblique, thin rugosities. Ventral part of the head reticulate; some specimens with small, dense, irregular foveae and rugosities on the anterior half. Pedicel minutely reticulate-punctate and with small, slightly irregular foveae. Pleurae strongly reticulate and with few, thin, longitudinal rugosities. Anterior third of the first gastral tergite strongly reticulate and with superficial, irregular foveae separate by thin, slightly longitudinal rugosities; similar sculpture on the remaining parts of the tergite but less impressed. Gastral sternites strongly reticulate, the reticulation more superficial on the center of the first sternite. Legs strongly reticulate and with minute, superficial, foveae, more impressed and denser on the outer face of the tibiae.

Pilosity. Body foveae with appressed hairs. Vertexal angles, posterior border of the gastral tergites and legs with rare, clubbed hairs. Gastral sternites with two types of pointed hairs: (1) sparse and short, and (2) rare and long on the second gastral sternite only. Remaining body parts without foveae with sparse, appressed, thin, short hairs only.

Colour. Brown to black with the frontal carinae and the membranaceous expansions of the body slightly lighter.

Measurements (in mm) and indices: TL 3.44-4.34; HL 0.84-1.02; HW 0.96-1.14; EL 0.22-0.24; PW 0.73-0.95; PeW 0.60-0.76; PpW 0.55-0.67; HBaL 0.29-0.36; HBaW 0.10-0.12; CI 112.0-116.3; PI 120.0-131.5; PPeI 121.7-137.3; PPpI 132.7-148.4; HBal 31.4-34.0.

Soldier

de Andrade and Baroni Urbani (1999) - Head disc suboval, longer than broad. Border of the disc strongly raised and with crenulate margin posteriorly. Floor of the disc medially with a pointed tumulus. Posterior part of the disc depressed.

Mesosoma. Humeral angles with a pair of obtuse, semi-membranaceous teeth. Pronotal sides gently converging posteriorly. Pronotal carina well marked, with variably crenulate margin and shortly interrupted medially. Mesonotal sides with a pair of broad, triangular teeth, sometimes with almost round tip. Propodeum with differentiate basal and declivous faces; sides of the basal face gently convex or with a small pair of irregular teeth followed by a pair of short, stout teeth curved upwards in large specimens.

Pedicel as in the worker but with narrower and shorter spines.

Mid and hind femora dorsally angulate; hind femora superficially carinate dorsally.

Gaster oval and with a pair of protruding lobes with marked margins.

Sculpture. Head dorsum with large, deep foveae, smaller on the tumulus, denser almost on the whole disc in small specimens and more clumped on the two posterior thirds of the floor of the disc than on its borders of the larger soldiers. Interspaces between the foveae porous. Sides of the disc punctate, densely and irregularly foveolate-rugulose, the foveae diminishing in size anteriorly; in some specimens the foveae more regular around the eyes; in other specimens the sides of the disc completely covered by slightly longitudinal rugosities. Ventral part of the head punctate, variably shining and covered by small foveae and irregular rugosities less impressed on median part. Mesosoma minutely reticulate-punctate and with dense foveae, larger on the pronotum, smaller on the propodeum. Pedicel with sculpture similar to that on the propodeum but with smaller foveae. Pleurae strongly reticulate; propleurae variably and irregularly foveolate-rugose. Gaster and legs with sculpture similar to that of the worker.

Pilosity. The foveae on the head dorsum with an erect, brush-shaped hair of variable size; those on the mesosoma, pedicel, gaster and legs with an appressed or decumbent, weakly canaliculate hair. Borders of the disc and foveae of the sides of the head with erect, long, variably clavate hairs; some specimens with rare brush hairs originating from the lateral foveae. Vertexal angles, pronotum, pedicel, gastral tergites and legs with rare clubbed hairs. Gastral sternites with two types of pointed hairs: sparse and short, and rare and long on the second gastral sternite only. Body parts without foveae with sparse, appressed, thin, short hairs.

Colour. Dark brown to black.

Measurements (in mm) and indices: TL 5.52-7.12; HL 1.52-1.92; HW 1.44-1.72; EL 0.29-0.32; PW 1.32-1.68; PeW 0.76-0.80; PpW 0.69-0.80; HBaL 0.37-0.40; HBaW 0.14-0.15; CI 89.6-94.7; PI 102.4-109.1; PPeI 173.7-210.0; PPpI 191.3-210.0; HBaI 37.5-37.8.

Queen

de Andrade and Baroni Urbani (1999) - Differing from the soldier in the following details.

Sides of the disc with the borders slightly lower; few specimens with the border very low. Humeral angles with a pair of short, triangular teeth or simply obtuse. Pronotal crest lower. Pronotum, mesonotum and scutellum flat in side view. Sides of the basal face of the propodeum anteriorly convex and posteriorly with a small pair of pointed teeth, slightly diverging laterally or directed backwards in some specimens only.

Petiole. Anterior face oblique and slightly concave. Petiolar sides with a pair of pointed denticles. Postpetiole convex dorsally and with broad lateral spines with truncate apex and pointed backwards.

Gaster. Similar to the one of the soldier but much longer.

Legs with less impressed carinae on the outer face of the hind femora.

Sculpture. Foveae of the head dorsum slightly larger than in the soldier. Mesonotal foveae shallower. Pleurae reticulate. Propleurae with thin, superficial, slightly longitudinal rugosities. Lower meso- and metapleurae with thin, longitudinal rugosities. Upper mesopleurae and upper border of the upper metapleurac with small foveae.

Pilosity. As in the soldier except for the clubbed hairs thinner, longer and more abundant on the pedicel, on the gaster and on the legs and also present on the whole mesosoma.

Colour. Dark brown to black.

Measurements (in mm) and indices: TL 7.40-8.20; HL 1.52-1.72; HW 1.44-1.56; EL 0.34-0.36; PW 1.28-1.44; PeW 0.64-0.68; PpW 0.77-0.80; HBaL 0.47-0.50; HBaW 0.15-0.16; CI 90.7-94.7; PI 108.3-112.5; PPeI 200.0-211.8; PPpI 166.2-180.0; HBaI 31.9-32.0.

Male

de Andrade and Baroni Urbani (1999) - Similar to the other species of the group from which it differs for one or more of the following characters: frontal carinae not raised. Clypeus convex posteriorly and superficially incised anteriorly in some specimens only.

Mesosoma. Pronotum in dorsal view with traces of scapular angles.

Sculpture. Head dorsum minutely reticulate. Posterior third of the head dorsum irregularly foveolate-rugose; frons with rare, minute foveae. Remaining head dorsum with thin rugosities oriented transversally in front of the eyes and longitudinal on the frons. Ventral part of the head reticulate, irregularly foveolate-rugulose, the rugae oblique to transversal around the eyes. Pronotum minutely reticulate and with irregular foveae, deeper on the sides. Mesonotum with minute, superficial reticulation, variably shining and with small, variably clumped, superficial, foveae. Scutellum with similar sculpture as on the mesonotum but with denser foveae; some specimens with few thin, longitudinal rugosities. Basal face of the propodeum reticulate and longitudinally rugulose. Pedicel with superficial and minute reticulation and with few, small foveae and short rugosities on the sides. Propleurae reticulate and sometimes with few, longitudinal, thin rugosities. Mesopleurae superficially reticulate and with thin, longitudinal rugosities on the posterior half; this sculpture covered by superficial, small foveae on the center of the lower and of the upper mesopleurae. Metapleurae reticulate and irregularly rugose; the rugosities oriented longitudinally on the lower part. Gaster almost smooth and shining. Legs punctate with moderately shining femora.

Pilosity as for the other species of the group.

Colour. Black. Coxae and gaster brown. Legs dark yellow.

Measurements (in mm) and indices: TL 4.82-4.96; HL 0.73-0.75; HW 0.91-0.93; EL 0.35-0.36; PW 0.75-0.80; PeW 0.33-0.34; PpW 0.36-0.39; HBaL 0.54-0.56; HBaW 0.07; CI 124.0-124.6; PI 113.7-124.0; PPeI 220.6-242.4; PPpI 192.3-222.2; HBaI 12.9-12.5 (?).

Type Material

de Andrade and Baroni Urbani (1999) - Worker, soldier, gyne and male. Original description. Type locality: Quebrada de Oro (Canal Zone, Panama). Type material: 8 workers, 4 soldiers labelled: "Quebrada de Oro, C. Z., Mar. 13.1943, W. M. W, Cordia alliodora, cotype 1-12, 21093-21094", Museum of Comparative Zoology.

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 486, Combination in Cephalotes, page 486, Revived from synonymy and raised to species)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168 (page 151, Junior synonym of pallens)
  • Wheeler, D. E.; Hölldobler, B. 1986 ("1985"). Cryptic phragmosis: the structural modifications. Psyche (Cambridge) 92:337-353. [1986-04-27] PDF
  • Wheeler, W. M. 1942. Studies of Neotropical ant-plants and their ants. Bull. Mus. Comp. Zool. 90: 1-262 (page 210, pl. 52 soldier, worker, queen, male described)