Cephalotes cordatus

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Cephalotes cordatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. cordatus
Binomial name
Cephalotes cordatus
(Smith, F., 1853)

Cephalotes cordatus P casent0900245.jpg

Cephalotes cordatus D casent0900245.jpg

Specimen Label

Synonyms

Nothing is known about the biology of Cephalotes cordatus.

Identification

de Andrade and Baroni Urbani (1999) - A member of the depressus clade characterised, in the worker and in the soldier, by the pronotum with a pair of continuous, slightly convex lamellae and by the meso- and metapleurae densely covered with thick hairs, and, in the gyne, by an incomplete disc, by the mesopleurae densely covered with thick hairs and by a low pronotal crest.

The specimens examined exhibit a great variation in body shape, particularly in the shape of the head and of the pronotum in dorsal view. The Amazonian specimens don't seem to differ significantly from the typical specimen from Para in MHNG. The extremes of variation we observed can be typified by the following examples: three workers from Chapada differ from the typical cordatus for the gaster with thin hairs; another worker from Chapada and one from Rio Madeira, Camp. 39, differ for the pleurae with few, thick hairs; three workers from Rio Madeira, two workers from Chapada, a worker from Sinop, a worker from Reserva Ducke and a worker from Alto Paraiso, Goias differ from the typical cordatus for the humeral angles more round and for the peduncular segments more broad. A worker from Gama and one from Vilhena have the vertexal angles without lamellae. The soldiers from Rio Madeira and Utiariti have the frontal carinae slightly converging over the eyes and the pronotal sides more convex. The soldiers from Reserva Florestal Ducke and Piaui have the frontal carinae slightly converging in front of the eyes and the sides of the disc weakly carinate. A soldier from Satipo (Peru) differs from typical ones for the pronotal sides more convex, for the pronotal carinae reduced, for the gaster oval and long and for the peduncular segments narrow.

Keys including this Species

Distribution

Colombia, French Guiana, Brazil, Peru, Bolivia

Distribution based on Regional Taxon Lists

Neotropical Region: Bolivia, Brazil (type locality), Colombia, Ecuador, French Guiana, Peru.

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.

  • cordatus. Cryptocerus cordatus Smith, F. 1853: 220, pl. 21, fig. 3 (w.) BRAZIL. Emery, 1894c: 202 (s.). Combination in Paracryptocerus: Kempf, 1951: 213; in Zacryptocerus: Brandão, 1991: 385; in Cephalotes: Baroni Urbani, 1998: 326; De Andrade & Baroni Urbani, 1999: 317. Senior synonym of boliviensis: Kempf, 1951: 213.
  • boliviensis. Cryptocerus cordatus var. boliviensis Santschi, 1921h: 126, fig. 2 (w.q.) BOLIVIA. Junior synonym of cordatus: Kempf, 1951: 213.

Description

Worker

Kempf (1951) - Length 5.5 mm. Black; the following ferruginous: frontal carinae, occipital lobes, lateral border of pronotal lamellae, tip of epinotal and peduncular spines.

Head broader than long, sides slightly diverging caudad. Frontal carinae distinctly crenulate, expanded and somewhat upturned above the eyes, the anterior half with projecting setulae within the notches. Lateral pronotal lamellae broad, broadest in front, anterior corner subangulate, sides scarcely convex, broadest in front, distinctly converging caudad. Mesonotum with an acute lateral tooth. Sides of epinotum with an anterior plate-like, recurved spine and a posterior, shorter, triangular tooth, usually somewhat removed forward from the posterior corner of the declivous face. anterior border of the petiole evenly rounded, including the spines, which are truncate at apex. Postpetiolar spines curving forward at base, recurved at apex, truncate. Gaster slightly elongate, cordiform.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.80-6.04; HL 1.12-1.38; HW 1.48-1.80; EL 0.40- 0.48; PW 1.40-1.72; PeW 1.04-1.20; PpW 0.82-1.10; HBaL 0.42-0.52; HBaW 0.15-0.20; CI 127.5-136.0; PI 103.6-107.2; PPeI 134.5-150.0; PPpI 151.8-195.6; HBaI 35.7-38.8.

Soldier

Kempf (1951) - Length 7.2 mm. Black; the tibiae and tarsi fuscous-ferruginous. Head subquadrate. Anterior corners rounded, posterior corners obliquely truncate and crested. Frontal carinae crenulate, slightly upturned in front of, somewhat emarginate above, the eyes. Upper surface of head scarcely convex, very finely punctate, coarsely foveolate, subfulgid. Vertex with a median transverse bidentate crest, and a lateral oblique carina between each denticule and the sides of the head. Occiput truncate. Lower border of occiput scarcely emarginate mesally. Thorax subfulgid, finely reticulate. Shoulders vestigial. Pronotum greatly expanded at the sides, with a strong transverse crest above, notched, but scarcely interrupted mesally. Mesonotum finely, but sharply reticulate-punctate, with a blunt lateral lobe. Mesoepinotal suture impressed, slightly arcuate caudad. Basal face of epinotum with a conspicuous postero-lateral lobe, which bears an upturned tubercular tooth above on the posterior corner. Upper surface and sides of thorax rather densely foveolate. Upper half of declivous face scaled and foveolate. Petiole and postpetiole as in worker, slightly stouter. All foveolae contain a golden, scale-like hair.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 7.30-8.68; HL 1.80-2.12; HW 2.28-2.56; EL 0.48-0.58; PW 2.24-2.60; PeW 1.14-1.40; PpW 1.10-1.28; HBaL 0.52-0.62; HBaW 0.25-0.27; CI 115.4-126.7; PI 92.1-103.4; PPeI 172.7-203.2; PPpI 190.0-210.0; HBaI 43.3-48.1.

Queen

de Andrade and Baroni Urbani (1999) - Head subquadrate, dorsally convex and with an incomplete disc. Frontal carinae strongly crenulate, expanded anteriorly, converging posteriorly before the eyes and straight posteriorly up to the vertexal angles. Vertexal angles slightly truncate and with minutely crenulate margin. Vertex with a pair of well developed, median teeth connected each other by a superficial carina continuing laterally as a thin margin until the frontal carinae. Mandibles with a thick lateral carina.

Mesosoma. Scapular angles short but visible in dorsal view. Humeral angles with a pair of broad, obtuse, lamellaceous teeth converging posteriorly. Pronotal carina superficially marked and interrupted in the middle by a superficial impression. Mesonotum and scutellum flat in side view. Lower mesopleurae with a n obtuse tooth. Basal face of the propodeum short. Sides of the basal face of the propodeum with two pairs of teeth subequal in size. Declivous face of the propodeum narrowing posteriorly.

Petiole with concave anterior border and anteriorly declivous dorsally; anterior half of the petiolar sides diverging into a pair of teeth, the posterior half converging posteriorly. Postpetiole broadly convex dorsally; its sides with a pair of broad spines arising from the anterior border and curved backwards.

Gaster marginate up to the stigma, slightly protruding anteriorly.

Legs. Fore coxae 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 small foveae variably clumped, shallower on the frontal carinae. Ventral part of the head with sculpture similar to the one on the dorsum but slightly shining and with the foveae larger and deeper. Basal face of the propodeum, pedicel and mesopleurae with oval, dense, foveae. Propleurae reticulate and with foveae on the dorsal and on the anterior thirds; propleurae with additional longitudinal, thin rugosities on the posterior half. Metapleurae reticulate and with foveae on the centre and on the anterior half of the higher part and with additional, longitudinal, thin rugosities on the ventral part. Outer face of coxae with rare, thin, rugosities, transversal on the fore coxae and longitudinal on the mid and hind coxae. Gaster and legs reticulate. Anterior and posterior thirds of the first gastral tergite, posterior half of the remaining tergites, outer face of the distal part of the femora and outer face of the tibiae with irregular, dense, superficial foveae, larger on the anterior third of the first gastral tergite.

Pilosity. Body with four types of hairs: (1) thick, appressed, originating from the foveae; (2) thinner and shorter than those originating from the foveae on the legs and on the gaster; (3) clavate, suberect on the frontal carinae, on the mesosoma, on the pedicel, on the gaster and on the legs, longer on the posterior border of the gastral tergites and sternites; (4) sparse, thin, long, slightly pointed on the gastral sternites.

Colour. Black. Frontal carinae dark ferruginous. Tibiae dark orange to ferruginous.

Measurements (in mm) and indices: TL 9.00; HL 1.68; HW 194; EL 0.49; PW 1.92; PeW 1.02; PpW 1.24; HBaL 0.60; HBaW 0.28; CI 115.5; PI 101.0; PPeI 188.2; PPpI 154.8; HBaI 46.7.

Type Material

Holotype Specimen Labels

de Andrade and Baroni Urbani (1999):

Worker. Type locality: Santarem (Para, Brazil). Type material: presumably lost (neither in The Natural History Museum nor in Oxford University Museum of Natural History). We regard as adelphotype (i. e. a specimen originating from the same series as the type but not seen by the author of the original description, a worker in Musee d'Histoire Naturelle Genève labelled as follows: first label: "Cotype" [printed], second label: "Cryptocerus cordatus Sm., Para" [probable handwriting of Guerin], third label: "Sp. C. cordatus, Sm." [handwriting of Guerin], fourth label: "Coll. Forel." printed].

Cryptocerus cordatus var. boliviensis. Worker and gyne. Type locality: Rio Guapay (Bolivia). Type material 1 worker, 1 gyne labelled "Bolivie, Rio Guapay, Lizer et Deletang" in Naturhistorisches Museum Basel, examined.

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 385, 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 317, Combination in Cephalotes)
  • Emery, C. 1894d. Studi sulle formiche della fauna neotropica. VI-XVI. Bull. Soc. Entomol. Ital. 26: 137-241 (page 202, soldier described)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244. (page 213, Combination in Paracryptocerus, senior synonym of boliviensis)
  • 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 220, pl. 21, fig. 3 worker described)