Cephalotes inca

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Cephalotes inca
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. inca
Binomial name
Cephalotes inca
(Santschi, 1911)

Cephalotes inca P casent0217837.jpg

Cephalotes inca D casent0217837.jpg

Specimen Label

Specimens have been collected from dry thorn forest.

Identification

A member of the basalis clade characterised, in the worker, by the frontal carinae upturned over the eyes, by the vertexal angles with triangular tooth, by the pointed anterior and posterior border of the pronotal lamellae, and by the length of the propodeal and petiolar spines, both longer than the basal face of the propodeum, and, in the gyne, by the secondary loss of the gastral coloured spots. C. inca shares with its closest relative, Cephalotes basalis, in the worker, the expanded pronotal lamellae with pointed anterior corner, the frontal carinae strongly upturned over the eyes, the vertexal angles triangular, the sides of the propodeum with a denticle (absent in some specimens) followed by a broad, pointed tooth and a long spine, and the long petiolar spines, and, in the gyne, the presence of a pair of vertexal denticles and the elongate propodeal and peduncular spines similar to those of the worker. The two gynes from Peru tentatively identified by us as inca differ from the gyne of Cephalotes basalis by the absence of the pair of yellow spots on the first gastral tergite, by the much broader foveae on the head and by the weakly angulate vertexal angles. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Ecuador, Peru (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.

  • inca. Cryptocerus multispinus st. inca Santschi, 1911i: 278 (w.) PERU. [Also described as new by Santschi, 1913h: 40.] De Andrade & Baroni Urbani, 1999: 279 (q.). Combination in Cryptocerus (Paracryptocerus): Emery, 1924d: 307; in Paracryptocerus: Kempf, 1951: 208; in Zacryptocerus: Brandão, 1991: 386; in Cephalotes: De Andrade & Baroni Urbani, 1999: 278. Raised to species: Kempf, 1967e: 362.

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) - Vertexal angles triangular. Vertexal margin concave, only laterally marginate and medially with a short "neck". Cheeks completely marginate inferiorly. Frontal carinae strongly upturned over and converging after the eyes. Eyes very large. Anterior clypeal horder concave. Mandibles with lateral carinae.

Mesosoma little convex in side view. Pronotum in dorsal view with the anterior border convex. Pronotal sides bearing broad lamellae; anterior border of the lamellae pointed, lateral border straight or gently concave, and the posterior one obtuse. Mesonotal teeth pointed. Propodeal suture variably impressed dorsally. Propodeum with differentiated basal and declivous faces; basal face often with a small denticle followed by a pointed, broad tooth and a thin, pointed spine longer than the face itself.

Petiole anteriorly truncate. Petiolar spines thin, pointed backwards and longer than the basal face of the propodeum. Petiolar dorsum with a faint transversal carina delimiting the anterior and posterior faces and medially with another longitudinal carina. Postpetiolar spines s lightly curved distally. Postpetiolar dorsum with a longitudinal carina on the posterior half.

Gaster with a broad membranaceous anterior lamella, surpassing the first gastral stigma at least.

Fore femora broader than the hind ones. Hind and mid femora bidenticulate medially; mid and hind basitarsi laterally compressed.

Sculpture. Head dorsum, mesosoma and abdominal pedicel reticulate-punctate and densely foveolate. Ventral face of the head and propleurae reticulate-punctate, with superficial foveae and slightly rugulose. Lower face of the vertexal angles and dorsal third of the pleurae slightly shining. Declivous face of the propodeum, distal outer face and sides of the legs reticulate-punctate and with faint longitudinal rugosities.

First gastral tergite, ventral part of the meso- and metapleurae, distal outer face of the legs densely covered with small, oval, superficial foveae. First gastral sternite with few longitudinal, slightly anastomosing rugulae on its sides, the rest reticulate-punctate and slightly shining in the middle.

Pilosity. Head dorsum, mesosoma, pedicel, gaster, distal outer face of the femora and tibiae, ventral part of the meso- and metapleurae densely covered by canaliculate, appressed hairs. Ventral part of the head, propleurae, sides of the legs and first gastral sternite with the same hairs as above, but sparser. Legs with sparse, short, thick suberect hairs; similar hairs but longer on the apex of the gaster.

Colour. Black with the sides of the frontal carinae, the sides of the pronotal lamellae, the crest of the gaster, the masticatory margin of the mandibles, the apex of the propodeal and pedicular spines ferrugineous. Hairs golden.

Measurements (in mm) and indices: TL 5.46-6.44; HL 1.32-1.60; HW 1.68-2.04; EL 0.45-0.49; PW 1.60-1.88; PeW 1.28-1.68; PpW 0.96-1.20; HBaL 0.64-0.72; HBaW 0.2-0.24; CI 127.3-127.5; PI 105.0-108.5; PPeI 111.9-125.0; PPpI 156.6-166.7; HBaI 31.2.-33.3.

Queen

de Andrade and Baroni Urbani (1999) - Head subquadrate, convex and without disc. Frontal carinae broadly expanded anteriorly and straight posteriorly up to the posterior border of the eyes. Vertexal angles almost round, poorly angulate. Vertex with a pair of denticles. Mandibles with a lateral carina.

Mesosoma. Humeral angles with a broad, obtuse tooth. Pronotal carina marked in the middle and obsolete on the sides. Mesonotum and scutellum flat in side view. Lower mesopleurae with a denticle. Basal face of the propodeum laterally with two pairs of broad, pointed teeth, the posterior pair longer than the anterior one. Declivous face of the propodeum with posteriorly converging sides.

Petiole with distinct anterior and posterior faces; anterior face oblique; the posterior face declivous posteriorly and with a pointed spine directed backwards on the sides. Postpetiole broadly convex, with a strong incompletely "U" shaped dorsal carina; postpetiolar spines arising from the anterior border of the postpetiole and little curved.

Gaster marginate anteriorly by a narrow lamella.

Legs. Fore coxae with a tumulus anteriorly. Mid and hind femora angulate. Mid and hind basitarsi flat and broad at the base.

Sculpture. Head, mesonotum, propodeum, pedicel and ventral part of the meso- and metapleurae superficially reticulate-punctate and covered by foveae broader than their interspaces, the foveae denser on the propodeum oval on the pedicel and meso- and metaplcurae, sparse and large on the ventral part of the head. Declivous face of the propodeum, dorsal half of the metapleurac, femora, and tarsi superficially reticulate-punctate and shining. Anterior and posterior faces of the tibiae similarly sculptured with superimposed fine, longitudinal rugosities. Anterior and posterior fourths of the first gastral tergite, distal part of the outer face of the femora and outer face of the tibiae covered with dense oval foveae; the foveae sparser on the remaining tergites. Sternites superficially reticulate-punctate. Almost shining, and with sparse superficial foveae.

Pilosity. Each fovea with an appressed, canaliculate hair of size proportional to the one of the foveae. Mandibles, mesosoma, pedicel and legs with rare, slightly clavate, suberect hairs. Second and remaining tergites and sternites with sparse, long, truncate hairs, rare on the first gastral tergite.

Colour. Black. Tip of the last funicular joints ferrugineous. Canaliculate hairs golden.

Measurements (in mm) and indices: TL 11.60-11.78; HL 2.44-2.48; HW 2.68-2.72; EL 0.62-0.64; PW 2.60-2.64; PeW 1.48-1.56; PpW 1.44-1.48; HBaL 0.88; HBaW 0.32; CI 108.1-111.5; PI 103.0-103.1; PPeI 160.0-175.7; PPpI 178.4-186.1; HBaI 3 6.4-36.6.

Type Material

de Andrade and Baroni Urbani (1999) - Worker. Type locality: La Massa (sic) (Peru). Type material: three syntype workers labelled "Museum Paris, Perou, La Masa, (400 m. d'alt.), P. Rivet 1906", 2 in Naturhistorisches Museum Basel, 1 in Musee d'Histoire Naturelle Genève, 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 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 279, queen described, page 278, Combination in Cephalotes)
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 307, Combination in Cryptocerus (Paracryptocerus))
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 208, Combination in Paracryptocerus)
  • Kempf, W. W. 1967e. A new revisionary note on the genus Paracryptocerus Emery (Hym. Formicidae). Stud. Entomol. 10: 361-368 (page 362, Raised to species)
  • Santschi, F. 1911i. Formicides de diverses provenances. Ann. Soc. Entomol. Belg. 55: 278-287 (page 278, worker described)