Cephalotes pallidoides

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Cephalotes pallidoides
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. pallidoides
Binomial name
Cephalotes pallidoides
De Andrade, 1999

Cephalotes pallidoides casent0173694 profile 1.jpg

Cephalotes pallidoides casent0173694 dorsal 1.jpg

Specimen labels

Nothing is known about the biology of Cephalotes pallidoides.

Identification

A member of the pallens clade differing from its sister species Cephalotes pallidus by the following apomorphies: in the worker, soldier and gyne, sculpture less impressed, femora more inflate, and HBaI ≥ 50 and, in the gyne only, disc with shallower and more regular foveae. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Ecuador, Guyana, Paraguay, Trinidad and Tobago, 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.

  • pallidoides. Cephalotes pallidoides De Andrade, in De Andrade & Baroni Urbani, 1999: 480, figs. 222-224 (s.w.q.m.) BRAZIL.

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

Description

Worker

The characters listed below should allow an exhaustive differential comparison with Cephalotes pallidus.

Border of the frontal carinae and of the membranaceous expansions of the mesosoma weakly crenulate. Femora much more incrassate. Mid and hind femora angulate. Mid and hind basitarsi flat, shorter and broader.

Sculpture. Head and mesosoma with shallower foveae, dense or sparse on the frontal carinae, with thin rugosities between the foveae in some specimens only. Ventral part of the head with or without small, irregular foveae separate by short, longitudinal rugosities. Propodeum and pleurae without longitudinal rugosities. Anterior third and sides of the first gastral tergite with shallower foveae. First gastral sternite and legs with more superficial reticulation and foveae.

Pilosity. As in pallidus but with the hairs on the border of the frontal carinae sparser and thinner some specimens with less short, erect, pointed, hairs on the gastral sternites.

Colour. Brown to black with the membranaceous expansions lighter.

Measurements (in mm) and indices: TL 3.79-4.44; HL 0.90-1.00; HW 1.00-1.20; EL 0.23-0.26; PW 0.90-1.1.02; PeW 0.65-0.77; PpW 0.53-0.70; HBaL 0.20-0.26; HBaW 0.11-0.13; CI 111.1-122.2; PI 111.1-123.9; PPeI 124.3-147.8; PPpI 140.0-192.4; HBaI 50.0-61.9.

Soldier

Differing from pallidus in the following characters.

Border of the cephalic disc less crenulate. Disc flat to gently convex medially. Vertexal angles and pronotal carina less crenulate. Sides of the basal face of the propodeum with two pairs of slightly round swellings. Gastral lobes less protruding. Femora more incrassate. Mid and hind femora dorsally more angulate.

Sculpture. Body foveae more regular. Foveae of the head dorsum approaching more the borders of the disc. Internal border of the disc with a narrow punctate area without rugosities. Some specimens with the head completely covered by a thick layer of probable camouflage material. Sides of the head more regularly foveolate. Ventral part of the head with thinner rugosities. Mesosoma, pleurae and pedicel with less impressed punctures and foveae. Gaster and legs with more superficial reticulation, foveae and rugosities.

Pilosity. Sides of the head disc, pronotum, pedicel, gaster and legs with sparser, clubbed hairs. Each fovea of the mesosoma, pedicel, gaster and legs with an appressed hair. Gastral sternites with less, short, erect, pointed, hairs.

Colour. Brown to black.

Measurements (in mm) and indices: TL 5.08-5.64; HL 1.36-1.56; HW 1.22-1.48; EL 0.31-0.34; PW 1.16-1.34; PeW 0.64-0.75; PpW 0.60-0.71; HBaL 0.23-0.25; HBaW 0.13-0.14; CI 89.7-97.4; PI 105.2-114.5; PPeI 181.2-194.2; PPpI 174.6-212.7; HBaI 50.0-61.5.

Queen

Differing from the soldier in the following characters. Floor of the disc flat posteriorly, declivous and with raised border anteriorly. Vertexal depression deeper. Humeral angles obtuse. Pronotal carina lower. Pronotum, mesonotum and scutellum flat. Sides of the basal face of the propodeum anteriorly convex and posteriorly with a pair of minute denticles slightly diverging externally.

Anterior face of the petiole more oblique and gently concave medially. Petiolar sides with a pair of small denticles. Postpetiolar sides with a pair of expansions variably developed, round apically or, sometimes, bearing a pair of minute denticles pointed backwards.

Gastral lobes more protruding.

Legs as in the soldier.

Sculpture. As in the soldier but the foveae cover the whole disc. Foveae on the mesosoma variably impressed. Foveae on the propodeum slightly smaller. Upper mesopleurae and center of the lower mesopleurae foveolate, the foveae denser and deeper on the upper mesopleurae.

Pilosity. As in the soldier except for the slightly denser clubbed hairs on the mesosoma, pedicel, gaster, and legs.

Colour. As in the soldier.

Measurements (in mm) and indices: TL 7.22-7.84; HL 1.48-1.64; HW 1.32-1.52; EL 0.36-0.39; PW 1.32-1.48; PeW 0.52-0.66; PpW 0.62-0.74; HBaL 0.32-0.37; HBaW 0.18-0.20; CI 89.2-92.7; PI 100.0-109.1; PPeI 212.9-253.8; PPpI 180.1-212.9; HBaI 50.0-59.4.

Male

Differing from pallidus in the following characters. Frontal carinae lower. Clypeus convex posteriorly, straight or with a superficial incision anteriorly. Pronotum in dorsal view with the sides diverging backwards; lateral margination of the pronotum variably developed.

Sculpture. Head dorsum minutely reticulate; posterior third of the head dorsum irregularly foveolate-rugose; frons with sparse, small foveae and thin, longitudinal rugosities. Sides of the head in front of the eyes and area between the scapes with thin, transversal rugosities. Ventral part of the head, mesosoma and pedicel as in pallidus except for the presence of longitudinal rugosities on the declivous face of the propodeum; rugosities on the mesopleurae more impressed. Gaster subopaque to shining.

Pilosity as for the other species of the group.

Colour. Black with lighter pedicel and gaster. Coxae and two proximal thirds of the femora brown. Remaining parts of the legs dark yellow.

Measurements (in mm) and indices: TL 4.46-5.17; HL 0.71-0.75; HW 0.88-0.96; EL 0.35-0.40; PW 0.88; PeW 0.39; PpW 0.43-0.47; HBaL 0.39-0.46; HBaW 0.07-0.08; CI 123.9-12 8.0; PI 100.0-109.1; PPeI 225.6; PPpI 187.2-204.6; HBaI 17.4-17.9.

Type Material

Holotype soldier from Brazil labeled: Utiariti (325 m), Rio Papagaio, Mato Grosso, Brasil, VII.1961, K. Lenko. Paratypes: 8 workers, 1 male, same data as the Holotype, all Museu de Zoologia da Universidade de Sao Paulo.

Etymology

Pallidoides is a neologism indicating the close relationship between this species and pallidus.

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 480, figs. 222-224 soldier, worker, queen, male described)