Cephalotes clypeatus

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Cephalotes clypeatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. clypeatus
Binomial name
Cephalotes clypeatus
(Fabricius, 1804)

Cephalotes clypeatus casent0010689 profile 1.jpg

Cephalotes clypeatus casent0010689 dorsal 1.jpg

Specimen labels

Specimens have been collected from forest habitats. Little else is known about the biology of Cephalotes clypeatus.

Identification

A member of the clypeatus clade characterised in the worker and in the soldier by the body shining yellowish to light brown with the head, mesosoma, pedicel and gaster surrounded by a transparent lamella, and, in the soldier, by the vertexal angles with a pointed spine, and, in the gyne, by two pairs of whitish spots surrounded by a dark border on the gaster. C. clypeatus shares with Cephalotes membranaceus and Cephalotes ustus several characters, the most visible of which is the gaster surrounded by a broad lamella. These three species can be easily distinguished by the colour and by the consistency of the lamellae around the body. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Colombia: Meta, Trinidad and Tobago, Venezuela, Guyana, French Guiana, Brazil, Peru, Bolivia, Argentina and Paraguay

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Bolivia, Brazil, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, 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.

  • clypeatus. Cryptocerus clypeatus Fabricius, 1804: 420 (w.) CENTRAL AMERICA. Smith, F. 1853: 217 (q.m.); Forel, 1906d: 235 (s.); Wheeler, G.C. & Wheeler, J. 1954b: 152 (l.). Combination in Cephalotes: Emery, 1914c: 39; in Cryptocerus (Zacryptocerus): Wheeler, W.M. 1916d: 326; in Zacryptocerus: Wheeler, W.M. 1911f: 175; Emery, 1915i: 192; Santschi, 1916e: 283; in Cephalotes: De Andrade & Baroni Urbani, 1999: 286. See also: Kempf, 1951: 136; Kempf, 1973c: 456.

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 6.5-10.0 mm. Ochraceous to yellowish brown. Head, thorax and gaster fulgid, sparsely covered with small, shallow foveolae, each containing a minute decumbent, scale-like hair. Head transverse, broader than long. Mandibles densely punctate-rugulose, fulgid. Clypeus triangular, its anterior border emarginate, the sides converging behind, the sutures visible. Frontal area small, vestigial. Frontal carinae diverging behind, somewhat upturned laterad, subtranslucid, slightly more pigmented, sculptured and subopaque along the margin. Occipital corners subspinosc, acute. Occipital border crested, more or less sinuate. Eye-stalk fused above with the frontal carinae; eyes small. Cheeks immarginate below. Upper surface of thorax, except the expanded laminate and translucid border, more or less flat. Anterior border of pronotum more or less straight, with a narrow subhyaline crest. Scapular spine long, upturned, and recurved distad, contained within a broadly expanded subhyaline border. Transverse pronotal crest absent, except a median single denticule. Promesonotal suture absent. Mesonotum with a lateral membranaceous, slightly upturned subhyaline tooth. Mesoepinotal suture present. Epinotum not distinctly divided into a basal and declivous face, moderately convex, its sides expanded into a broad, rounded somewhat upturned subhyaline border, containing a few pigmented strands representing the vestiges of the epinotal spines. Femora moderately incrassated at the proximal third, attenuate distad. Basitarsi of mid and hind legs compressed, yet not as thin as in Cephalotes. Both the tibiae and the basitarsi have elongate, dense grooves, containing a decumbent hair. Petiole more than twice as broad as long, with an anterolateral, slightly recurved tooth, the anterior border marginate, the ventral face with a hyaline median tooth. Postpetiole broader, with a lateral, plate-like, apically rounded lobe, curving forward. Gaster oval, depressed, surrounded by a narrow, hyaline, upturned, translueid border, interrupted mesally in front for the reception of the postpetiole.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 7.20-8.96; HL 1.76-2.12; HW 2.88-3.16; EL 0.32-0.39; PW 2.80-3.48; PeW 0.88-1.00; PpW 0.88-0.96; HBaL 1.10-1.24; HBaW 0.28-0.31; CI 162.5-172.7; PI 90.8-108.6; PPeI 304.3-348.0; PPpI 327.3-362.5; HBaI 23.3-25.4.

Soldier

Kempf (1971) - This caste has the cephalic disc with the sides less diverging caudad, its surface more distinctly and densely foveolate; the vertex bears a pair of teeth at the bases of which are connected by a low transverse carina, which is however lacking between each tooth and the lateral margin of head. Pronotum with a well-developed transverse carina, the anterior and posterior portion of thorax forming in side view a blunt angle the vertex of which is the carina. Propodeal spines well-developed, solid and stout with the enclosing hyaline margin. Intermediates seem to be more frequent and differ from the minor worker only by the presence of a pair of unconnected teeth on vertex, a weak, often incomplete transverse pronotal carina, and the solid spine within the lateral propodeal margin.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 10.05-11.24; HL 2.48-2.60; HW 3.64-3.84; EL 0.42-0.44; PW 3.88-4.16; PeW 1.16-1.20; PpW 1.10-1.16; HBaL 1.28-1.32; HBaW 0.32-0.34; CI 146.7-147.7; PI 92.3-93.8; PPeI 334.5-346.6; PPpI 352.7-358.6; HBaI 24.2-26.5.

Queen

Kempf (1951) - Length 13 mm. Median head length 2.53 mm; Weber's length of thorax 4.05 mm. Ochraceous; the following ferruginous: Antennae, tarsi, mandibles. First gastral tergite with a pale yellowish macula, surrounded by a fuscous ring, open towards the outer margin, on each corner. Parts of the frontal carinae and crests of the pronotum are subhyaline and semitranslucid.

Head subfulgid above, subopaque below; subquadrate. Mandibles visible from above, finely rugulose, sparsely punctured, the apices curved obliquely downward. Clypeus retracted, subtriangular, anterior border emarginate. Frontal area vestigial. Frontal carinae greatly expanded, covering the sides of the head from above, extending backwards to the occipital corner; semitransparent, laterally straight, upturned, rounded anteriorly. Upper surface of head slightly concave discad, microscopically and rather sparsely punctured, covered with large, sparse, rounded foveolae, each containing a small, whitish, decumbent scale. Ocelli forming an equilateral triangle, situated on large pits, on the side walls. Behind the posterior ocelli two short, stout, acute spines.

Occipital angle with a similar spine, its base continuous with frontal carinae and sending out a crest, downwards and mesad toward the occipital foramen, fading out shortly before reaching it. A sharp crest separating the cheek from the lower surface of the head. Scape attenuate at base, incrassated discad. Eyes situated behind the antennal scrobe.

Thorax fulgid, one and a half times as long as broad; sparsely foveolate, each foveola containing a decumbent seta. Anterior border of pronotum scarcely emarginated mesad, slightly crested. Shoulders with a large, angular, protruding crest, marginating the sides until it gives off, on each side, the transverse pronotal crest, the remaining part of the lateral border of the pronotum immarginate. Laterotergite of pronotum flat. Mesonotal sclerites flat. Parapsidal furrows of scutum vestigial. Scutum almost twice as broad as long. Mesopleura convex, the lower half without an antero-ventral tooth. Basal face of epinotum extremely short, mesad, marginate and crested laterad, forming an acute, crested angle caudad, where the crest turns mesad, for one fourth of the width. Declivous face almost three times as long as basal face, somewhat excavated. Mid and hind basitarsus broadened and flattened, almost as in the female Cephalotes. Femora, tibiae and tarsi with elongate, decumbent long hair.

Petiole twice as broad as long, impressed above, mesad, its anterior border slightly emarginate. Densely foveolate above and laterad, sides slightly converging caudad. Anterior half of the ventral face with a median crest, ending in an acute tooth anteriorly. Postpetiole more than twice as broad as long, with an anterolateral, projecting blunt, marginate and crested lobe, the dorsal face greatly convex above longitudinally and transversely, sculptured as petiole.

Gaster fulgid, elongate, suboval, sides subparallel. Anterior corners not crested, but lobate, immarginate. Both the tergites and sternites are very finely and shallowly foveolate except on the posterior border of the sclerites where the foveolae become crowded and the integument rugulose.

Wings subhyaline. Veins dark brunneous. Fore wing with a black stigma. Marginal cell infuscated, closed, appendiculate, narrow, and elongate. Submarginal cell elongate, its apical half infuscated. A fuscous streak along the veins in the apical field and in the costal margin. No transverse cubital vein. Discoidal cell small.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 13.40-14.10 HL 2.56-2.60; HW 2.88-3.08; EL 0.48; PW 2.92-3.20; PeW 1.00-1.16; PpW 1.20-1.28; HBaL 1.32-1.36; HBaW 0.35-0.39; CI 112.5-118.4; PI 96.2-98.6 PPeI 275.8-292.0; PPpI 243.3-250.0; HBaI 26.5- 28.7.

Male

Kempf (1951) - Length 8.4 mm. Median head length 1.26 mm; Weber's length of thorax 2.80 mm. Black; the following stramineous: Mandibles, antennae, legs, excluding the coxae, gaster. Brunneous: clypeus, a central patch discad on each of the three parts of the scutum, metanotum, edges of lateral sclerites of thorax, fore coxae, peduncle; the postpetiole ferruginous.

Head subopaque, transverse, median head length shorter than distance between the eyes. Mandibles finely ruguloso-punctate, with a longitudinal crest basad. Chewing border finely crenulate with a distinct apical and minute preapical tooth. Clypeus transverse, evenly convex, not forming two faces, anterior and posterior border arcuate. Frontal carinae raised to a conspicuous triangular acute tooth between the antennal sockets, diverging behind, fading out before the posterior half of the eyes. Front finely punctate-rugulose. Antennal scrobe obsolete. Cheeks, vertex, occiput and lower surface of head more coarsely reticulate-rugose, interspersed with larger setigerous foveolae. Ocelli on vertex, large, raised above the surface of the head, the lateral ones larger than the antero-median ocellus. Occiput perpendicular to the upper surface of head, immarginate above, slightly excavated beneath mesad, occipital angles obsolete. Checks, in anterior aspect, diverging caudad, subcontinuous with the anterior border of the mandibles, scarcely emarginate. Eyes large, slightly shorter than half the median head length. Scape shorter than half the length of the 2nd funicular segment. Segments 2-12 of funiculus more than twice as long as broad.

Thorax subfulgid; 1.5 times as long as maximum width. Anterior border of pronotum moderately arcuate, with bluntly angulate, projecting shoulder. Median portion of the dorsal face and the laterotergite of the pronotum mostly smooth and fulgid, the postero-lateral portions of the above rather coarsely foveolate-rugose. Scutum smooth and fulgid, sparsely and shallowly foveolate, the Mayrian furrows not fusing mesad behind. Scutellum similarly sculptured, the anterolateral lobes separated from the body by a very deep transverse furrow. Metanotum subopaque. Upper and lower portion of metapleura greatly convex and bulging. Epinotum unarmed, densely foveolate above, rather smooth and fulgid laterad and on the declivous face. Mid and hind basitarsi flattened basad. Legs fulgid. Claws stout, with a blunt basal tooth.

Petiole subquadrate from above. Upper surface smooth and fulgid, sides scarcely converging caudad, with a few scattered foveolae below. Pospetiole slightly broader than long, with a blunt tubercle projecting from each side. Upper face convex in profile.

Sculpture as petiole.

Gaster oval, perfulgid. Exposed portions of tergites 2-6 with very fine, inconspicuous microsculpture. (The genitalia were lost).

Pilosity long, pale creamy, sparser than in Cephalotes. Erect on head and thorax, appressed on appendages.

Wings as in female.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: T L 7.00-8.68; HL 1.08-1.28; HW 1.32-1.60; EL 0.41-0.52; PW 1.46-1.84; PeW 0.66-0.76; PpW 0.73-0.84; HBaL 0.78-0.96; HBaW 0.15-0.20; CI 122.2-125.0; PI 86.9-90.4; PPeI 221.2-242.1; PPpI 200.0-219.0; HBaI 19.2-20.8.

Type Material

de Andrade and Baroni Urbani (1999) - Worker. Type locality: "in America meridionali", actually Essequibo, Guyana. Type material: 2 syntype workers in the Zoologisk Museum, University of Copenhagen and 2 syntype workers belonging to the Zoologisches Museum Kiel equally deposited in ZMUC (Zimsen, 1964: 427) (examined). Only one of the ZMUC syntypes bears a locality label: "Essequibo, Smidt, Mus. de Sehestedt, Cryptocerus clypeatus Fabr."

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 286, Combination in Cephalotes)
  • Emery, C. 1914e. Intorno alla classificazione dei Myrmicinae. Rend. Sess. R. Accad. Sci. Ist. Bologna Cl. Sci. Fis. (n.s.) 18: 29-42 (page 39, Combination in Cephalotes)
  • Fabricius, J. C. 1804. Systema Piezatorum secundum ordines, genera, species, adjectis synonymis, locis, observationibus, descriptionibus. Brunswick: C. Reichard, xiv + 15-439 + 30 pp. (page 420, worker described)
  • Forel, A. 1906d. Fourmis néotropiques nouvelles ou peu connues. Ann. Soc. Entomol. Belg. 50: 225-249 (page 235, soldier described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 136, see also)
  • Kempf, W. W. 1973c. A new Zacryptocerus from Brazil, with remarks on the generic classification of the tribe Cephalotini (Hymenoptera: Formicidae). Stud. Entomol. 16: 449-462 (page 456, see also)
  • Smith, F. 1853 [1854]. Monograph of the genus Cryptocerus, belonging to the group Cryptoceridae - family Myrmicidae - division Hymenoptera Heterogyna. Trans. Entomol. Soc. Lond. (2) 2: 213-228 (page 217, queen, male described)
  • Wheeler, G. C.; Wheeler, J. 1954b. The ant larvae of the myrmicine tribes Cataulacini and Cephalotini. J. Wash. Acad. Sci. 44: 149-157 (page 152, larva described)
  • Wheeler, W. M. 1911g. A list of the type species of the genera and subgenera of Formicidae. Ann. N. Y. Acad. Sci. 21: 157-175 (page 175, Combination in Zacryptocerus)
  • Wheeler, W. M. 1916f. Ants collected in Trinidad by Professor Roland Thaxter, Mr. F. W. Urich, and others. Bull. Mus. Comp. Zool. 60: 323-330 (page 326, Combination in Cryptocerus (Zacryptocerus))