Cephalotes spinosus

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Cephalotes spinosus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. spinosus
Binomial name
Cephalotes spinosus
(Mayr, 1862)

Cephalotes spinosus P casent0217844.jpg

Cephalotes spinosus D casent0217844.jpg

Specimen Label

Synonyms

A few stray workers were found in dense second growth with a few larger trees (Barinas, Venezuala). Nothing else is known about the biology of Cephalotes spinosus.

Identification

A member of the laminatus clade characterised in the worker by the unarmed mesonotum and by the golden hairs on the mesosoma, in the soldier by the broad gastral lamellae and by the unarmed mesonotum, and in the soldier and gyne by the frontal carinae orange and semi-transparent. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname, Trinidad and Tobago, Venezuela.

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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.

Castes

Nomenclature

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

  • punctatus. Cryptocerus punctatus Mayr, 1862: 762 (w.) BRAZIL. Junior synonym of spinosus: Dalla Torre, 1893: 144; Emery, 1924d: 308.
  • spinosus. Cryptocerus spinosus Mayr, 1862: 761 (w.) BRAZIL. Forel, 1911e: 260 (s.); Kempf, 1951: 187 (q.). Combination in Cryptocerus (Paracryptocerus): Emery, 1915i: 192; in Paracryptocerus: Kempf, 1951: 187; in Zacryptocerus: Brandão, 1991: 388; in Cephalotes: De Andrade & Baroni Urbani, 1999: 220. Senior synonym of punctatus: Dalla Torre, 1893: 144; Emery, 1924d: 308; of peruvianus: Kempf, 1967e: 361.
  • peruvianus. Cryptocerus laminatus subsp. peruvianus Forel, 1911c: 297 (s.) PERU. Combination in Cryptocerus (Paracryptocerus): Emery, 1924d: 308; in Paracryptocerus: Kempf, 1951: 191. Subspecies of spinosus: Forel, 1911e: 260. Junior synonym of spinosus: Kempf, 1967e: 361.

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

Description

Worker

Kempf (1951) - Length 5.2 mm. Median head length 1.29 mm; Weber's length of thorax 1 .68 mm. Black; the following yellowish-brown: frontal carinae, occipital lamellae, lamellate border of the first gastral tergite. Ferruginous: first and tip of terminal funicular segments, spines of thorax and peduncular segments, tips of femora, tibiae, fore tarsi, distal half of mid and hind tarsi.

Head subopaque, slightly broader than long, broadest behind the eyes, narrowed in front. Interocular distance subequal to maximum length of head (64:65). Posterior margin scarcely concave. Occipital angles with projecting, obliquely truncate lamellae, the apical border of which is sinuate. Cheeks strongly marginate beneath, densely covered with appressed, scale-like hairs. Upper and lower surface of head microscopically reticulate-punctate, sparsely covered with golden, slender, appressed scales. A few broader and canaliculate scales towards the occipital border.

Thorax subopaque. Anterior border moderately arcuate, shoulders angulate. Lateral border of pronotum with two subequal, strong, scarcely recurved and somewhat raised spines. Posterior corners of pronotum not projecting, confluent with the lateral border of the mesonotum. Promesonotal suture vestigial. Mesonotum unarmed at the sides. Thorax scarcely constricted laterad between mesonotum and epinotum. Mesoepinotal suture distinct and impressed. Basal face of epinotum, excluding the spines, about twice as long as broad, with two spines arising from its lateral border on each side. The anterior spine subequal to the prothoracic spines, the posterior spine very strong, twice as long, pointing sidewards and only slightly backwards. Microsculpture sharper, with superimposed, mostly longitudinal and rather dense rugosities on the dorsal face, between which lie rather dense, golden, canaliculate, appressed scales. Sides of thorax with longitudinal striae and sparse canaliculate scales. Declivity not excavated. Legs finely reticulate-punctate with simple, flattened hairs as on head.

Petiole subopaque, transverse, with distinctly set off, long, slender, apically recurved and rounded lateral spines, arising from the anterior corner. Postpetiole as long as, narrower than, the petiole, with shorter, broader and apically rounded lateral spines, curving obliquely forward. Sculpture of peduncle similar to head and gaster.

Gaster subopaque, cordiform, longer than broad. First gastral tergite with broad, anterolateral, transparent lamellae, the outer margin of which is slightly upturned; as broad as length of postpetiole. Tergites and sternites finely and rather sharply reticulate-punctate. Scales of gaster simple, sparse, becoming slightly denser towards the apex of the first tergite. Erect pile limited to 2d to 4th tergites and sternites.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.80-5.80; HL 1.16-1.44; HW 1.60-1.92; EL 0.35-0.43; PW 1.28-1.60; PeW 0.68-0.76; PpW 0.60-0.68; HBaL 0.56-0.60; HBaW 0.11-0.13; CI 133.3-137.9; PI 120.0-131.2; PPeI 168.4-210.5; PPpI 191.0-235.3; HBaI 17.8-21.6.

Soldier

Kempf (1951) - Length 7.6 mm. Median head length 1 .85 mm. Webers's length of thorax 2.22 mm. Black; the following ferruginous: frontal carinae, first funicular segment, tip of femora, tibiae apices of metatarsi, tarsi, apices of thoracic spines, peduncular spines. Lamellate border of gaster pale yellowish. Tip of last funicular segment orange.

Head subfulgid; subquadrangular, shorter than wide; anterior corners rounded; posterior corners slightly projecting in a short, stout, bluntly rounded tooth. Frontal carinae prolonged above the eyes in the form of a distinctly raised, carinule, fading out before reaching the occi pital corner. Upper surface of head moderately convex. Cheeks not distinctly marginate beneath. Eyes little convex. A distinct carina extends from beneath the eyes back to the occipital corner. Vertex with a pair of tuberculate swellings on the immarginate occipital border. Upper and lower surface of head finely punctate, more sparsely foveolate, foveolae on upper surface of head rounded, without conspicuous hair. Occiput smooth, fulgid, sparsely foveolate.

Thorax smooth and fulgid above, sides and declivous face of epinotum opaque, finely reticulate-punctate. Anterior border arcuate, shoulders subangulate, not well visible from above. Pronotum with a transverse crest, broadly interrupted mesad, ending laterad in a stout, apically rounded, short spine, projecting outward, another spine in front of this. Sides distinctly converging cephalad and caudad from the second spine. Promesonotum, in profile, greatly convex. Promesonotal suture distinct. Mesonotum on each side with a minute, inconspicuous denticule. Thorax greatly constricted between mesonotum and epinotum. Basal face of epinotum with a small triangular tooth laterad, and a large, stout, apically bluntly rounded spine, arising from the posterior corner, projecting outward and upward. Dorsum of thorax covered with rather dense, deeply impressed rounded setiferous foveolae; somewhat denser on basal face and upper third of declivous face of epinotum. Remainder of declivous face and sides of thorax without any conspicuous macrosculpture.

Petiole transverse, with a long, very slender, apically obtuse, slightly recurved spine on each side. Postpetiole with plate-like broad, rounded, lateral projection on each side. Both segments finely reticulate-punctate, opaque.

Gaster subfulgid, subcordiform, finely and densely punctured with sparse, very shallow, vestigial foveolae. Anterolateral border of first gastral tergite with a subtranslucid, excavated broad lamellate crest, as in worker.

Pilosity scarcer than in worker. All foveolae except the ones on the upper surface of head, contain a small, distinctly visible, decumbent, flat seta, which is more or less glistening on epinotum. Gaster with minute appressed setulae. Erect pile confined to the apical portion of the gaster as in other species.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 6.62-8.00; HL 1.66-2.04; HW 2.28-2.72; EL 0.50-0.52; PW 1.84-2.32; PeW 0.91-0.96; PpW 0.80-0.90; HBaL 0.68-0.72; HBaW 0.16-0.19; CI 131.4-137.3; PI 115.5-123.9; PPeI 191.7-254.9; PPpI 224.4-260.7; HBal 22.2-26.4.

Queen

de Andrade and Baroni Urbani (1999) - Head almost round, dorsally convex. Frontal carinae surpassing the posterior border of the eyes posteriorly as a thin margin. Vertexal angles with a pair of small, triangular teeth. Vertex with a pair of small, median, stout teeth. Clypeus concave anteriorly and with a pair of small lateral denticles. Eyes convex. Mandibles broad, without tumulus and denticles.

Mesosoma. Scapular angles visible in dorsal view. Humeral angles with a pair of pointed anterior spines. Pronotal carina superficially marked, interrupted in the middle, and absent laterally in some specimens. Mesonotum and scutellum flat. Lower mesopleurae with a variably developed, stout tooth. Sides of the basal face of the propodeum with or without a small pair of swellings followed by a long spine directed backwards; sides of the declivous face converging posteriorly.

Petiole with the anterior face concave and oblique medially; petiolar sides gently diverging posteriorly, unarmed or with a small pair of denticles medially. Postpetiole broadly convex dorsally; sides of the postpetiole with stout and round expansions.

Gaster anteriorly with a pair of broad, variably protruding, marginate lobes.

Legs. Fore coxae tumuliform anteriorly. Mid and hind femora not angulate. Hind basitarsi not flat and with almost parallel sides.

Sculpture. Head dorsum minutely and superficially reticulate-punctuate and with small, variably clumped, superficial foveae. Venlral face of the head, pronotum and scutellum smooth and with dense, deep, foveae larger than their interspaces; propleurae with similar sculpture but more impressed and superficially reticulate. Mesonotum smooth and with sparse, shallow foveae. Basal face and anterior half of the declivous face of the propodeum, upper metapleurae, petiolar sides and postpetiole with dense, deep, slightly irregular foveae. Lower meso- and metapleurae reticulate and with variably clumped foveae. Posterior half of the declivous face of the propodeum reticulate. Gaster smooth or superficially reticulate. Anterior third of the first gastral tergite with sparse, superficial foveae. Legs reticulate. Extensor face of the tibiae with small, irregular foveae.

Pilosity. Body with four type of hairs: (1) short, thin, appressed originating from a fovea on the head and on the mesosoma, or arising from very superficial foveae on the gaster and on the legs; (2) long, rare, slightly clavate on the pronotal sides, on the pedicel, on the first tergite and on the legs; (3) similar to type (2) but truncate on the remaining tergites; (4) long, dense and pointed on the sternites.

Colour. Black, slightly shining. Frontal carinae yellow-orange and transparent. Femora dark orange. Gaster with two pairs of yellow spots, one on the anterior third and the other larger and on the posterior third.

Measurements (in mm) and indices: TL 11.58-12.06; HL 2.12-2.34; HW 2.68-2.84; EL 0.56; PW 2.48-2.60; PeW 1.04-1.28; PpW 1.36-1.40; HBaL 0.80-0.87; HBaW 0.20-0.24; CI 121.4-126.4; PI 108.1-109.2; PPeI 203.1-238.5; PPpl 182.3-185.7; HBal 25.0-27.6.

Type Material

de Andrade and Baroni Urbani (1999):

Worker. Type locality: Amazon River (Brazil). Type material: Lectotype worker in Naturhistorisches Museum Wien, Vienna (Kempf, 1951: 187), labeled "Pernambuco, Coll. G. Mayr, spinosus G. Mayr, Type", examined and one syntype worker, same data and same collection as the lectotype, equally in NHMW, examined.

Cryptocerus punctatus. Soldier. Type locality: Amazon River (Brazil). Type material: not available for the present study.

Cryptocerus laminatus peruvianus. Solider. Type locality: Chanchamayo, 1200 m (Peru). Type material: one soldier labelled: "Chanchamayo X, Peru, 1200 m; Cryptocerus spinosus Mayr r. peruvianus Forel, soldier type; r. Cr. Peruvianus Forel; Paracryptocerus spinosus peruvianus Forel = spinosus Mayr, Kempf, 1967".

References

  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 388, Combination in Zacryptocerus)
  • Dalla Torre, K. W. von. 1893. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. Vol. 7. Formicidae (Heterogyna). Leipzig: W. Engelmann, 289 pp. (page 144, Senior synonym of punctatus)
  • 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 220, Combination in Cephalotes)
  • Emery, C. 1915g. Noms de sous-genres et de genres proposés pour la sous-famille des Myrmicinae. Modifications à la classification de ce groupe (Hymenoptera Formicidae). Bull. Soc. Entomol. Fr. 1915: 189-192 (page 192, Combination in Cryptocerus (Paracryptocerus))
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 308, Senior synonym of punctatus)
  • Forel, A. 1911g. Die Ameisen des K. Zoologischen Museums in München. Sitzungsber. Math.-Phys. Kl. K. Bayer. Akad. Wiss. Münch. 11: 249-303 (page 260, soldier described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 187, queen described, page 187, Combination in Paracryptocerus)
  • Kempf, W. W. 1967e. A new revisionary note on the genus Paracryptocerus Emery (Hym. Formicidae). Stud. Entomol. 10: 361-368 (page 361, Senior synonym of peruvianus)
  • Mayr, G. 1862. Myrmecologische Studien. Verh. K-K. Zool.-Bot. Ges. Wien 12: 649-776 (page 761, worker described)