Cephalotes jamaicensis

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Cephalotes jamaicensis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. jamaicensis
Binomial name
Cephalotes jamaicensis
(Forel, 1922)

Cephalotes jamaicensis P casent0627947.jpg

Cephalotes jamaicensis D casent0627947.jpg

Specimen Label

Specimens have been collected from a nest in dead wood from secondary scrub habitat.

Identification

A member of the pallens clade characterised by the following apomorphies: in the worker the propodeum with a pair of narrow, membranaceous, lateral expansions, in the soldier by the head disc with contiguous foveae, by the hind femora with superficial carina, and by the head slightly broader than long. Workers resemble resemble Cephalotes varians in the propodeal and head shapes the large workers of varians from Yateras and Cienfuegos (Cuba). Small differences in microsculpture and propodeal morphology (see description below) may be regarded as sufficient to separate the two species. Soldier differs from varians soldiers by having the foveae of the head disc larger and contiguous on the whole disc (more spaced and absent on the border of the disc in varians). In addition, each fovea bears a subdecumbent or decumbent hair slightly longer than in varians. Other characters separating Cephalotes jamaicensis from varians in the soldier caste are the propodeal and pedicellar spines much larger in jamaicensis. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Greater Antilles, Jamaica (type locality).

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.

  • jamaicensis. Cryptocerus (Cyathocephalus) varians var. jamaicensis Forel, 1922: 97 (w.) JAMAICA. De Andrade & Baroni Urbani, 1999: 467 (s.). Combination in Cephalotes: De Andrade & Baroni Urbani, 1999: 465. Junior synonym of varians: Kempf, 1958a: 155. Revived from synonymy and raised to species: De Andrade & Baroni Urbani, 1999: 465.

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) - Differing from Cephalotes varians in the following: propodeal sides with a pair of broader membranaceous expansions slightly convex and gently converging posteriorly. Gaster with a pair of anterolateral membranaceous expansions of different thickness, continuing after the stigma as a carina.

Sculpture. Foveae on the head dorsum more superficial than in varians, shallower on the frontal carinae. First gastral tergite with denser and deeper foveae more impressed on the anterior half.

Pilosity. As in varians except for the gaster where the hairs arc more appressed.

Colour. Dark brown to black with slightly lighter legs.

Measurements (in mm) and indices: TL 4.56-4.96; HL 1.08-1.14; HW 1.28-1.34; EL 0.27-0.30; PW 1.06-1.16; PeW 0.65-0.72; PpW 0.61-0.64; HBaL 0.35-0.38; HBaW 0.12-0.13; CI 116.1-118.5; PI 115.5-120.7; PPeI 155.6-173.1; PPpI 173.8-196.6; HBaI 34.2-35.1.

Soldier

de Andrade and Baroni Urbani (1999) - Differing from varians in the following: head disc slightly broader than long, almost round. Floor of the disc more convex medially. Promesonotal suture less impressed. Sides of the basal face of the propodeum with a pair of small, triangular teeth followed by a pair of long, thick teeth strongly curved up and forwards. Declivous face of the propodeum narrowing posteriorly and with strongly carinate border.

Pedicel with well developed spines.

Gaster with a pair of strongly protruding anterior lobes.

Sculpture. Head dorsum minutely punctate, superficially shining and completely covered with large, dense, subhexagonal foveae contiguous each other. Posterior sides of the head with foveae similar to those on the head dorsum; the foveae less regular and smaller on the anterior sides of the head. Ventral part of the head reticulate, opaque and with small, slightly irregular foveae separate by short, irregular rugosities on the posterior sides and on the anterior half. Anterior third of the first gastral tergite covered by deep, oval foveae; the foveae more superficial on the remaining tergites and sternites.

Pilosity. Hairs arising from the foveae of the disc subdecumbent to decumbent and longer than in varians.

Colour. Black with slightly lighter legs.

Measurements (in mm) and indices: TL 6.95; HL 1.84; HW 1.90; EL 0.36; PW 1.78; PeW 0.72; PpW 0.72; HBaL 0.38; HBaW 0.15; CI 103.3; PI 106.7; PPeI 247.2; PPpI 247.2; HBaI 39.5.

Type Material

de Andrade and Baroni Urbani (1999) - Worker. Type locality: Kingston (Jamaica). Type material: 2 syntype workers in Musee d'Histoire Naturelle Genève labelled: "Kingston, Jard. bot. (Forel), Cryptocerus (Cyathocephalus) varians Sm. v. jamaicensis, worker, type, For., Cr. (Cy) v. jamaicensis For.", examined.

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 467, soldier described, page 465, Combination in Cephalotes, page 465, Revived from synonymy and raised to species)
  • Forel, A. 1922b. Glanures myrmécologiques en 1922. Rev. Suisse Zool. 30: 87-102 (page 97, worker described)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168 (page 155, Junior synonym of varians)