Cephalotes pavonii

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Cephalotes pavonii
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. pavonii
Binomial name
Cephalotes pavonii
(Latreille, 1809)

Cephalotes pavonii p casent0217841.jpg

Cephalotes pavonii D casent0217841.jpg

Specimen Label

De Oliveira et al. (2015), studying ant occupancy of Cecropia trees in southwest Bahia, Brazil, found a colony of Cephalotes pavonii opportunistically nesting in a Cecropia pachystachya tree.

Identification

A member of the depressus clade characterised, in the worker, by the pronotum with a pair of long, incised lamellae, in the worker and in the soldier, by the meso- and metapleurae with rare, thick hairs, in the soldier, by the pronotal lamellae triangular, and, in the gyne, by an incomplete disc, by the mesopleurae covered with few hairs and by the pronotal crest strongly crenulate. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Suriname.

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.

  • pavonii. Cryptocerus pavonii Latreille, 1809: 132 (w.) SOUTH AMERICA. Emery, 1890b: 73 (s.w.q.); Kempf, 1951: 224 (s.); De Andrade & Baroni Urbani, 1999: 327 (s.q.). Combination in Paracryptocerus: Kempf, 1951: 222; in Zacryptocerus: Brandão, 1991: 387; in Cephalotes: Baroni Urbani, 1998: 326; De Andrade & Baroni Urbani, 1999: 325.

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

de Andrade and Baroni Urbani (1999) - Kempf, 1951, regarded the specimens from Kartabo (Guyana) in the MCZ as those better fitting the original description of pavonii by Latreille (1809). As Kempf noticed correctly, the Latreillean species is very likely to have been named after M. Pavon, the author of the Flora of Peru, and, as such, it is probaly based on Peruvian material. Kempf wrote also correctly that the specimens identified as pavonii by most former authors actually belong to several different species. At the time of his admittedly tentative identification of the true pavonii, Kempf did not see Peruvian material of this group and his identification is based solely on the very short original description. We have been able to study only two Peruvian specimens of this group. The morphology of the humeral angles of these specimens fit better than the specimens from Guyana the Latreillean diagnosis " . . . thorace . . . ad angulos anticos producto, subcrenato" and we consider them heterospecific from the pavonii of Kempf who has much more dentate than crenate humeral angles (see the diagnosis). The specimens from Kartabo studied by Kempf have been attributed by us to a new species (Cephalotes palustris, q. v.).

Since Kempf's identification of the "true" pavonii is conjectural and the new, different identification we propose in this paper is also conjectural, one may argue that it would have been better to leave the things as they were. As a matter of fact, the conservative nomenclatorial solution is not without problems: the species called pavonii by Emery (1890) is in part Cephalotes borgmeieri and in part Cephalotes eduarduli and the pavonii of Forel (1912) is actually C. borgmeieri; even in the Kempf collection, we recognise three different species under the name pavonii (including what we regard as true pavonii). By fixing a neotype from Peru we wish to be as close as possible to the truth and to prevent future uncertainties about this species.

Description

Worker

de Andrade and Baroni Urbani (1999) - Head subquadrate. Vertexal angles with two pairs of teeth, the external pair small, variably pointed, the internal one large, triangular and lamellaceous. Vertex concave. Cheeks completely marginate below. Frontal carinae crenulate, broad, strongly upturned over the eyes and extending up to their posterior border backwards. Clypeal border broadly incised. Mandibles with superficial, lateral carinae. Eyes strongly convex.

Mesosoma convex in side view. Scapular angles well visible in dorsal view. Pronotal sides with broad lamellae; the lamellae directed laterally, their sides bidentate or crenulate, their posterior borders converging, with a small notch on the middle. Mesonotal teeth pointed. Propodeal suture variably impressed dorsally. Propodeum sloping backwards and slightly concave, without differentiate basal and declivous faces; its sides with a pair of spines followed by a pair of teeth, the anterior pair broad and with obtuse or pointed tip, the posterior one smaller, variably broad, and pointed. Petiole ca. 1/4 broader than postpetiole and with indistinct anterior and posterior faces. Petiolar dorsum declivous anteriorly. Anterior border of the petiole with a median concavity. Petiolar spines curved backwards, variably pointed, their sides not continuous with the anterior border of the petiole. Postpetiolar spines curved with the apices pointing backwards.

Gaster with a broad, lamellaceous anterior border reaching the first gastral stigma at least.

Hind and mid femora denticulate in the middle; mid and hind basitarsi laterally compressed.

Sculpture. Head dorsum, mesosoma and abdominal pedicel covered by reticulation and foveae, the foveae smaller and sparser on the anterior half of the head. Ventral face of the head superficially reticulate, with superimposed, anteriorly converging rugosities extending from the eyes to the submentum. Middle of the declivous face of the propodeum reticulate only. Sides of the mesosoma with longitudinal rugosities and faintly reticulate. Posterior half of the mesopleurae and middle of the metapleurae with superficial, oval foveae. First gastral tergite reticulate and with superficial foveae, the foveae denser on the anterior fourth. Corresponding sternite reticulate and slightly shining in the middle. Fore coxae reticulate and variably rugulose; mid and hind coxae with longitudinal rugosities on their extensor face. Femora and tibiae reticulate and with superficial foveae.

Pilosity. Each fovea bearing an appressed hair of size proportional to the one of the foveae. Sides of the head, of the mesosoma, peduncular segments, mandibles, legs, and gaster with short, clavate hairs. Sternites with sparse, long, suberect, truncate hairs.

Colour. Black. Frontal carinae, borders of the pronotal lamellae, tips of the propodeal and peduncular spines, gastral lamellae, tibiae and tarsi, dark orange to light brown.

Measurements (in mm) and indices: TL 4.12-5.30; HL 0.94-1.28; HW 1.28-1.68; EL 0.33-0.42; PW 1.34-1.76; PeW 0.84-1.08; PpW 0.68-0.84; HBaL 0.32-0.44; HBaW 0.10-0.15; CI 131.1-136.2; PI 95.4-95.5; PPeI 159.5-163.0; PPpI 197.1-209.5; HBaI 31.2-34.1.

Soldier

de Andrade and Baroni Urbani (1999) - Head subquadrate, with complete disc. Vertexal angles with two pairs of short, obtuse teeth. Head dorsum gently convex in the middle and slightly concave on the sides. Posterior border of the disc with a p air of developed median teeth connected each other by a median ridge, the ridge continuing markedly on the sides of the head into the frontal carinae. Frontal carinae with crenulate border and converging posteriorly. Mandibles broad, their sides with an impressed, round, carinate protuberance. Eyes gently convex.

Mesosoma broad anteriorly, narrowing posteriorly. Scapular angles little p rotuberant. Pronotal sides bearing a pair of developed, rectangular lamellae with converging sides posteriorly. Pronotal carina well impressed, raised, strongly crenulate and interrupted medially by an impression. Promesonotal suture impressed. Mesonotal sides with a pair of broad, short, obtuse or round tooth. Propodeal suture deeply impressed. Propodeum with slightly differentiated basal and declivous faces. Basal face broadening posteriorly and ending in a pair of broad, developed, rectangular, crenulate lamellae, its dorsum convex in the middle and on the same plane as the declivous face. Declivous face flat in the middle, its sides converging posteriorly and bearing medially a pair of short, triangular, lamellaceous teeth or a pair of continuos lamellae.

Petiolar node sloping anteriorly; its anterior border concave. Petiolar sides diverging posteriorly, with a median, well developed spine directed backwards. Postpetiole, in lateral view, slightly convex, dorsally gently concave; postpetiolar spines thick, arising from the anterior face and curved backwards.

Gaster suboval and with a broad anterolateral lobe, the lobe with a margin reaching the stigma.

Hind femora medially angulate. Hind basitarsi flat and with broad base.

Sculpture. Head superficially punctate and covered by large foveae broader than their interspaces, diminishing in size anteriorly. Vertexal angles and ventral sides of the head with foveae larger and deeper than those on the posterior part of the head. Centre of the ventral part of the head deeply reticulate and with sparse, small foveae. Pronotum and mesonotum reticulate and with foveae almost as broad as those on the posterior part of the head dorsum, the foveae denser on the mesonotum, on the middle and on the posterior half of the pronotum. Basal face of the propodeum, petiole and postpetiole reticulate and with dense, oval foveae. Extensor face of the femora, of the tibiae and anterior fourth of the first gastral tergite reticulate and with dense, small, oval, superficial foveae; this same sculpture but sparser to rare and superficial on the remaining gastral segments, on the pleurae and on the legs. Pleurae with thin, longitudinal rugosities. Declivous face of the propodeum reticulate only.

Pilosity. As in the worker; the short clavate hairs extend to the crenulations of the pronotal cannae.

Colour. Black, slightly shining. Frontal carinae, extensor face of the tibiae, tarsomeres, borders of the humeral angles and of the propodeal lamellae, tip of the last funicular joints and of the peduncular spines ferruginous to light brown.

Measurements (in mm) and indices: TL 6.86-7.38; HL 1.64-1.88; HW 2.06-2.28; EL 0.44-0.48; PW 2.12-2.36; PeW 1.08-1.28; PpW 0.92-1.12; HBaL 0.50-0.55; HBaW 0.17-0.20; CI 121.3-125.6; PI 96.6-98.3; PPeI 184.4-209.0; PPpI 210.7-230.4; HBaI 34.0-40.0.

Queen

de Andrade and Baroni Urbani (1999) - Head subquadrate, dorsally convex and with an incomplete disc. Frontal carinae strongly crenulate, expanded anteriorly, continuing straight posteriorly up to the vertexal angles. Vertexal angles slightly truncate and with two pairs of small denticles. Posterior border of the disc with a pair of well developed, median teeth connected each other by a faint carina continuing laterally until the frontal carinae. Mandibles laterally angulate.

Mesosoma. Scapular angles short but visible in dorsal view. Humeral angles with a pair of pointed spines. Pronotal sides straight. Pronotal carina marked, strongly crenulate and interrupted in the middle by a superficial depression. Mesonotum and scutellum flat in side view. Lower mesopleurae with an obtuse tooth. Basal face of the propodeum short. Sides of the basal face of the propodeum with two pairs of teeth of the same size. Declivous face of the propodeum with the sides converging posteriorly.

Petiole as in cordatus. Postpetiolar spines thinner than in cordatus.

Legs. Fore coxae anteriorly sharply angulate. Hind femora angulate. Mid and hind basitarsi compressed laterally, their proximal part broader than the distal one.

Sculpture. Dorsum of the head, of the pronotum, of the mesonotum and of the scutellum minutely punctate and with dense foveae, shallower on the frontal carinae, slightly larger on the pronotum. Ventral part of the head with sculpture similar to the one of the pronotum but with the punctures more impressed and with the foveae deeper. Basal face of the propodeum, pedicel and upper mesopleurae with irregular, dense, foveae. Propleurae reticulate and with foveae on the anterior third; propleurae with additional, longitudinal, thin rugosities on the posterior third. Lower mesopleurae reticulate and with foveae on the borders only; its centre with longitudinal, thin rugosities. Metapleurae reticulate and with thin, longitudinal rugosities. Outer face of the fore coxae with transversal, thin, rugosities. Outer face of the mid coxae with longitudinal, thin rugosities. Outer and posterior faces of the hind legs with longitudinal, thin rugosities. Gaster and legs reticulate. Anterior third of the first gastral tergite with irregular, superficial foveae; similar sculpture but with smaller foveae on the posterior border of the first gastral tergite, on the posterior half of the remaining tergites, on the outer face of the distal part of the femora and on the outer face of the tibiae.

Pilosity. As in cordatus.

Colour. Black, with mesosoma and pedicel darker, gaster lighter. Frontal carinae dark ferruginous. Tibiae and tarsi dark ferrugineous.

Measurements (in mm) and indices: TL 9.88; HL 1.88; HW 2.08; EL 0.45; PW 2.16; PeW 0.93; PpW 1.16; HBaL 0.65; HBaW 0.23; CI 110.6; PI 96.3; PPeI 232.2; PPpI 179.3; HBal 35.4.

Type Material

de Andrade and Baroni Urbani (1999) - Worker. Type locality: S America (probably Peru). Type material: presumably lost; neotype selected for the present study, a worker from Victoria, Junin (Peru), 01.VII.1938, W. F. Walker leg., bearing the identification label Paracryptocerus pavonii Latreille, det. W. W. Kempf (Museu de Zoologia da Universidade de Sao Paulo); a worker, same data as the neotype (Museum of Comparative Zoology).

References

  • Baroni Urbani, C. 1998b. The number of castes in ants, where major is smaller than minor and queens wear the shield of the soldiers. Insectes Soc. 45: 315-333 (page 326, Combination in Cephalotes)
  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 387, 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 327, soldier, queen described, page 325, Combination in Cephalotes)
  • Emery, C. 1890b. Voyage de M. E. Simon au Venezuela (Décembre 1887 - Avril 1888). Formicides. Ann. Soc. Entomol. Fr. (6)(10): 55-76 (page 73, soldier, worker, queen described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 224, soldier described, page 222, Combination in Paracryptocerus)
  • Latreille, P. A. 1809. Genera crustaceorum et insectorum secundum ordinem naturalem in familias disposita, iconibus exemplisque plurimus explicata. Tomus 4. Parisiis et Argentorati [= Paris and Strasbourg]: A. Koenig, 399 pp. (page 132, worker described)
  • de Oliveira, G. V., M. M. Correa, I. M. A. Goes, A. F. P. Machado, R. J. de Sa-Neto, and J. H. C. Delabie. 2015. Interactions between Cecropia (Urticaceae) and ants (Hymenoptera: Formicidae) along a longitudinal east-west transect in the Brazilian Northeast. Annales De La Societe Entomologique De France. 51:153-160. doi:10.1080/00379271.2015.1061231