Cephalotes liogaster

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Cephalotes liogaster
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. liogaster
Binomial name
Cephalotes liogaster
(Santschi, 1916)

Cephalotes liogaster casent0912603 p 1 high.jpg

Cephalotes liogaster casent0912603 d 1 high.jpg

Specimen Labels

Synonyms

Nothing is known about the biology of Cephalotes liogaster.

Identification

A member of the fiebrigi clade differing from its sister species Cephalotes lanuginosus in the worker, soldier and gyne by the smaller and less protruding eyes and by the more shining gaster. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina (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.

  • liogaster. Cryptocerus liogaster Santschi, 1916e: 381, fig. (w.) ARGENTINA. Combination in Paracryptocerus (Harnedia): Kempf, 1958a: 25; in Zacryptocerus: Brandão, 1991: 386; in Cephalotes: De Andrade & Baroni Urbani, 1999: 658. Senior synonym of fides: Kempf, 1958a: 25.
  • fides. Cryptocerus lobigaster var. fides Santschi, 1925e: 162 (s.w.q.) ARGENTINA. Junior synonym of liogaster: Kempf, 1958a: 25.

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

Description

Worker

Kempf (1958) - 4.4-5.2 mm. 1. Sculpture of first gastral tergite superficial to obsolete; integument always shining, often quite smooth. 2 . Thoracic and peduncular teeth or spines usually more acute, peduncular spines more reflexed caudad, especially in shinier specimens. 3. Postpetiole middorsally often, not always, acuminate as in fiebrigi. 4. First gastral tergite in general longer, with less convex sides and more pronounced anterolateral lobes. 5. Standing hair slightly longer, less crowded; scalelike, appressed hair more delicate and shorter, masking to a lesser degree the integument.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.32-5.16; HL 0.98-1.16; HW 1.06-1.26; EL 0.26-0.30; PW 0.92-1.12; PeW 0.51-0.60; PpW 0.54-0.59; HBaL 0.35-0.47; HBaW 0.09-0.12; CI 105.3-108.6; PI 107.1-116.7; PPeI 180.4-211.3; PPpI 170.4-196.5; HBaI 25.5-26.7.

Soldier

Kempf (1958) - Length 6.0-7.8 mm. 1. Head disc, shoulders, tips of posterior epinotal teeth, extensor face of tibiae yellowish-brown. Frequently, especially in larger, full-grown soldiers, the light color extends over the entire promesonotum and sometimes also the epinotum. In this case, the first gastral tergite is marked by four yellowish spots, variable in size, one at each corner. 2. Posterior epinotal teeth shorter, their tips never raised, but pointing obliquely caudad. 3. Peduncular spines more reflexed at apex. 4. Gaster more elongate, finely and densely punctate, but always shining.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 7.68-7.80; HL 1.68-1.76; HW 1.76-1.92; EL 0.33-0.34; PW 1.68-1.82; PeW 0.75-0.8; PpW 0.71-0.84; HBaL 0.44-0.52; HBaW 0.14-0.16; CI 104.8-109.1; PI 104.8-105.5; PPeI 224.0-227.5; PPpI 216.7-236.6; HBaI 30.8-31.8.

Queen

Kempf (1958) - Length 7.8-9.1 mm. 1. Head disc predominantly yellowish-brown. The same color prevails on the extensor face of the tibiae, the pronotum and also on the scutum, with the exception of two lateral and often one median black streaks on the latter. First gastral tergite with the customary four large testaceous spots, one at each corner. 2. Peduncular spines more recurved, the postpetiole narrower and longer, the anterior border of the gaster more deeply excised. 3. First gastral tergite finely but densely sculptured, the integument nevertheless quite shining.

Females of this species sometimes exhibit a striking variability in coloration and development of head disc, a phenomenon commonly observed only in the soldier caste. Two specimens, measuring 7.8 and 8.0 mm, have the head disc indistinctly marginate posterolaterally, in front of the occipital lobes. One specimen is rather dark, the light color being restricted to the border of the head disc, the tips of the scapular angles, the tibiae and the four spots on the gaster. A single winged specimen has the wings infuscated with dark brown veins. The fore wing measures 7.1 mm, and extends well beyond the posterior end of the gaster, when folded over the back.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 8.92-9.56; HL 1.64-1.76; HW 1.64-1.80; EL 0.36-0.39; PW 1.68-1.72; PeW 0.73-0.75; PpW 0.84-0.88; HBaL 0.58-0.64; HBaW 0.16-0.17; CI 100.0-102.3; PI 97.6-104.6; PPeI 229.3-230.1; PPpI 195.4-200.0; HBaI 25.0-29.3.

Type Material

de Andrade and Baroni Urbani (1999) –

Worker. Type locality: Estacion Sosa (Entre Rios, Argentina). Type material: 3 syntype workers in Naturhistorisches Museum, Basel (examined).

Cryptocerus lobigaster var. fides. Worker, soldier and gyne. Type locality: Fives Lille (Santa Fe, Argentina). Type material: 4 workers, 4 soldiers and 1 gyne, all syntypes in NHMB (examined); 1 worker labelled as paratype in Museu de Zoologia da Universidade de Sao Paulo, examined; additional syntype material presumably in the Museo Nacional de Historia Natural, Buenos Aires (not seen).

References

  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 386, 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 658, Combination in Cephalotes)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168 (page 25, Combination in Paracryptocerus (Harnedia), Senior synonym of fides)
  • Santschi, F. 1916e. Formicides sudaméricains nouveaux ou peu connus. Physis (B. Aires) 2: 365-399 (page 381, fig. worker described)