Cephalotes eduarduli

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Cephalotes eduarduli
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. eduarduli
Binomial name
Cephalotes eduarduli
(Forel, 1921)

Cephalotes eduarduli casent0173676 dorsal 1.jpg

Specimen labels

Specimens from one collection were from a forest edge. Little else is known about the biology of Cephalotes eduarduli.

Identification

A member of the depressus clade differing from its sister species Cephalotes depressus, in the worker, soldier and gyne, by the erect, truncate hairs on the mesosoma, on the pedicel and on the gaster, in the worker only by short pronotal lamellae and, in the soldier and in the gyne, by the shining head. The shape of the gaster is subject to intranidal variability; it can be either oval or round according to the specimen. The soldiers from Mato Grosso do Sul (Fazenda Yamaguti) and the gynes from Castilho (S. Paulo) have the frontal carinae orange ferruginous and semi-transparent instead of reddish, darker and opaque. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Brazil, Bolivia, Argentina and Paraguay.

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Bolivia, Brazil, Paraguay (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.

  • eduarduli. Cryptocerus eduarduli Forel, 1921a: 204 (s.w.q.) PARAGUAY. De Andrade & Baroni Urbani, 1999: 364 (m.). Combination in Paracryptocerus: Kempf, 1951: 221; in Zacryptocerus: Brandão, 1991: 386; in Cephalotes: Baroni Urbani, 1998: 326.

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) - Head subquadrate. Vertexal angles with two pairs of teeth, the external pair small, sometimes denticulate, obtuse, the internal one large, triangular and lamellaceous. Vertexal border deeply concave. Genae completely marginate below. Frontal carinae crenulate, broad, strongly upturned over the eyes and extending up to their posterior border backwards. Clypeal border incised. Mandibles with superficial lateral carinae. Eyes strongly convex.

Mesosoma convex in side view. Scapular angles well visible in dorsal view. Pronotal sides with a pair of lamellae followed by a deep notch and a pair of variably pointed or round teeth; pronotal lamellae narrow, rectangular, directed laterally and with bidentate or crenulate border. Mesonotum with a pair of pointed teeth. Promesonotal suture superficial in some specimens. Propodeal suture dorsally obsolete and variably impressed on the sides only. Propodeum sloping backwards, without differentiate basal and declivous faces; its sides with two pairs of pointed spines, the anterior pair broad and gently recurved in some specimens, the posterior one thinner and smaller than the first pair. Petiole almost flat and slightly broader than the postpetiole, its dorsum sloping anteriorly. Petiolar spines making an obtuse angle with the anterior border of the petiole, curved backwards, with truncate and crenulate apex. Postpetiolar spines curved with the apex pointing backwards.

Gaster with a thin, narrow margin not surpassing the stigma posteriorly.

Hind and mid femora with a pair of median denticles; mid and hind basitarsi laterally compressed and with the proximal part broader than the distal one.

Sculpture. Head dorsum superficially and minutely reticulate and with small foveae as broad as or slightly broader than their interspaces, larger and denser posteriorly, superficial on the frontal carinae. Ventral face of the head reticulate, with sparse, shallow foveae and with superimposed, short rugosities under the eyes. Pronotum and mesonotum reticulate and with foveae as broad as on the posterior part of the head, dense on the pronotum, sparser on the mesonotum. Anterior half of the propodeum and peduncular segments reticulate and with superficial, oval foveae. Posterior third of the propodeum with thin, longitudinal rugulae. Sides of the mesosoma reticulate, with oval foveae on the anterior part of the propleurae and on the posterior part of the meso- and metapleurae, this sculpture superimposed by thin, longitudinal rugosities. Tergites, distal part of the outer face of the femora and outer face of the tibiae strongly reticulate and with superficial, small foveae. Middle of the first gastral sternite and sides of the femora superficially shining.

Pilosity. Each fovea bearing an appressed hair of size proportional to the one of the foveae. Parts of the gaster and of the legs without foveae with thin hairs. Notches of the frontal carinae, mandibles, trunk, peduncular segments, gaster and legs with suberect, truncate hairs, denser on the apex of the gaster. Rare, suberect, long, pointed hairs on the apex of the sternites.

Colour. Black. Frontal carinae, border of the pronotal lamellae, apices of the thoracic and peduncular spines, extensor faces of the tibiae and tarsomeres orange-ferruginous.

Measurements (in mm) and indices: TL 4.76-5.64; HL 1.08-1.28; HW 1.44-1.68; EL 0.36-0.44; PW 1.48-1.72; PeW 0.97-1.12; PpW 0.80-0.96; HBaL 0.44-0.57; HBaW 0.15-0.20; CI 131.0-133.3; PI 97.3-100.0; PPeI 152.5-158.3; PPpI 1.72.1-190.0; HBaI 31.2-35.1.

Soldier

Kempf (1958) - Total length 7.8 mm. Maximum length of head 2.39 mm; of thorax 2.25 mm. Black; funiculus and apical four tarsites of all legs fuscous-brown.

Head wider than long (75:67). Mandibles finely punctate, opaque, their outer border distinctly angulate at the middle. Frontal carinae with scarcely crenulate border. Dorsum of head rather convex discad, sparsely foveolate, very finely punctate, shiny. Sides of head emarginate above the flattened eyes. Occipital angles obliquely truncate, marginate, the margination forming an obtuse tooth on each end. Vertex with a pair of projecting teeth in the middle, which are connected by a vestigial transverse carinule. Occiput perpendicular to vertex, its posterior border slightly convex. Gular face of head more coarsely reticulate-punctate, with rather oblong foveolae.

Thorax wider than long (73:63), subopaque, more coarsely punctate. Sides longitudinally rugose, the rugosities forming meshes on the mesopleura. Shoulders indistinct. Pronotum greatly expanded laterad, with an elevated, straight-edged, transverse crest, which is broadly interrupted mesally, and has laterally one or two shallow notches. Anterior corner of pronotal expansions with a pointed tooth. Behind the transverse crest, the sides of the pronotum are sinuous and converge strongly mesad. Promesonotal suture distinct. Sides of mesonotum with a large, rounded and projecting lobe. Mesoepinotal suture deeply impressed. Basal face of epinotum having on its posterior corner a stout lobe, which projects outward and upward, and bears on its apex two bluntly rounded teeth, the posteriormost tooth being largest and almost erect. Declivity not separated from the basal face by a carinule. Hind femora angulate and denticulate above, in the distal half.

Peduncular segments thrice as broad as long. Sculpture as on thorax, the foveolae being somewhat elongate. Petiole broader than postpetiole, bearing on each side a strong, acute, spine, which curves obliquely caudad. Postpetiole with a similar spine on each side, the apex of which points directly caudad.

Gaster longer than broad (70:60). Anterior border shallowly emarginate in the middle. First tergite opaque, finely and densely punctured, with scattered, more conspicuous piligerous points. Sternites and apical border of tergites with standing hair.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 6.80-8.16; HL 1.68-2.08; HW 2.12-2.56; EL 0.48-0.53; PW 2.08-2.68; PeW 1.20-1.32; PpW 1.00-1.22; HBaL 0.58-0.63; HBaW 0.21-0.23; CI 121.1-126.5; PI 95.5-101.9; PPeI 173.3-216.1; PPpI 208.0-233.3; HBaI 36.2-37.7.

Queen

de Andrade and Baroni Urbani (1999) - Head convex, without disc. Frontal carinae broad and with crenulate border; sides of the frontal carinae converging in front of the eyes and reaching the middle of the eyes. Vertexal angles with two pairs of small, obtuse denticles. Vertex with a pair of median, small denticles or protuberances. Clypeus slightly concave or incised anteriorly. Mandibles broad, with a lateral, carinate tumulus.

Mesosoma. Humeral angles with a pair of pointed anterior teeth. Pronotal sides straight. Pronotal carina narrow, not crenulate and superficially interrupted in the middle. Mesonotum and scutellum flat.

Lower mesopleurae with a small denticle. Basal face of propodeum generally with two pairs of teeth, the anterior pair sometimes absent or smaller and less pointed than the posterior ones; declivous face flat.

Petiole with the anterior border concave, its dorsum sloping anteriorly; petiolar sides with a pair of small, pointed spines. Postpetiole convex dorsally; sides of the postpetiole with a small, broad, obtuse tooth in their cranial half.

Gaster with a broad, not cranially protruding anterior border.

Legs. Fore coxae with a broad lobe anteriorly. Hind femora medially angulate. Hind basitarsi flat and broadened at their base.

Wings. Fore wings with R+Sc superficially connected to a marked pterostigma. 2r marked, Rsf5 connected with R1. Distal parts of A, Cu-A1 and Mf4 vestigial. Hind wings with R, M+CuA, M and lA marked; distal part of M, of CuA and of lA vestigial.

Sculpture. Head minutely and superficially punctate and covered by small foveae as broad as their interspaces, larger and deeper on the posterior part, superficial on the frontal carinae. Ventral part of the head reticulate and opaque anteriorly, shining posteriorly, the reticulation superimposed by deep foveae, slightly larger than those on the posterior part of the head dorsum. Mesosoma and pedicel reticulate-punctate and with foveae larger than those on the head dorsum, the foveae denser on the posterior part of the pronotum, on the basal face of the propodeum, on the petiolar sides, on the postpetiole, on the two posterior thirds of the mesopleurae and on the middle of the metapleurae. Pleurae with superficial, thin, longitudinal rugosities. Declivous face of the propodeum reticulate only. First gastral tergite and sternites reticulate-punctate and with small, superficial, piligerous punctures, the punctures deeper and denser on the anterior fourth of the first gastral tergite. Ventral part of the first gastral sternites shining. Legs reticulate and with piligerous punctures, the punctures denser on the extensor face of the femora and tibiae. Femora moderately shining on the sides.

Pilosity. Each fovea bears an appressed, canaliculate hair of size proportional to the one of the foveae; the hairs originating from the piligerous foveae thinner. Mandibles, sides of the head, trunk, peduncular segments, gaster and legs with slightly clavate, suberect hairs. Apex of the gaster with long, suberect, truncate hairs, similar hairs but sparser on the legs.

Colour. Black, gaster and legs lighter; frontal carinae, tarsomeres and extensor face of the tibiae dark ferruginous.

Measurements (in mm) and indices: TL 9.44-10.52; HL 1.78-2.00; HW 2.08-2.28; EL 0.48-0.52; PW 2.16-2.32; PeW 0.92-1.00; PpW 1.08-1.16; HBaL 0.67-0.73; HBaW 0.23-0.25; CI 112.0-117.8; PI 94.5-100.0; PPeI 216.0-247.8; PPpI 186.2-207.1; HBaI 34.2-35.2.

Male

de Andrade and Baroni Urbani (1999) - Head (eyes included, mandibles excluded) about 1/3 broader than long; vertexal margin straight, superficially carinate and ending in two almost round, carinate angles. Ocelli protuberant. Vertex little convex. Eyes broadly convex, in the middle of the sides of the head. Frontal carinae raised, strongly converging anteriorly, diverging backwards and not reaching the posterior border of the eyes. Frons flat and separate from the clypeus by a superficial furrow. Clypeus convex, its posterior half higher than the anterior one, almost truncate. Mandibles slender, laterally carinate and with a distinct apical tooth. Scapes thick, twice as long as the first funicular joint; remaining funicular joints thickening from the base to the apex.

Mesosoma. Pronotum in dorsal view broadening backwards, superficially carinate on the sides and with marked scapular angles; mesonotum convex; median Mayrian carina and parapsidal furrows weakly impressed; scutellum convex, its sides converging posteriorly; propodeum with poorly differentiate basal and declivous faces; basal face convex, its sides converging posteriorly towards the declivous face, the latter with lateral and median carinae.

Petiole slightly narrower than the postpetiole and with a deeply concave anterior border; petiolar sides convex medially or with a small, obtuse denticle. Postpetiole convex dorsally; postpetiolar sides with a pair of short, obtuse teeth in the middle.

Gaster almost as broad as the mesosoma.

Wings. As in the gyne.

Sculpture. Head and mesosoma deeply reticulate-punctate. Ventral part of the head with irregular and variably impressed, irregular rugulae; similar rugulae but more regular and transversal on the periocular area. Head and trunk with small, superficial, irregular foveae, the foveae smaller on the head, rare on the propleurae and absent on the metapleurae. Basal face of the propodeum with irregular rugosities becoming more regular on the metapleurae. Peduncular segments, first gastral tergite and sternite reticulate the reticulation more superficial on the legs and on the remaining gastral segments. Peduncular segments with few, thin, longitudinal rugosities.

Pilosity. Head and mesosoma covered by dense, long, suberect hairs, sparser and subdecumbent on the pedicel, on the gaster and on the legs. Funiculi densely covered by thin, short, decumbent hairs; similar but thinner, sparser and slightly longer hairs on the legs and on the gaster.

Colour. Head and mesosoma black, peduncular segments brown, first gastral segment ferruginous. Antennae, legs and remaining gastral segments yellow to light brown. Wings light ferruginous and infuscated.

Measurements (in mm) and indices: TL 6.12-6.88; HL 0.84-1.00; HW 1.16-1.36; EL 0.44-0.48; PW 1.16-1.32; PeW 0.60-0.68; PpW 0.68-0.76; HBaL 0.56-0.64; HBaW 0.12-0.14; CI 136.0-138.1; PI 100.0-103.0; PPeI 193.3-194.1; PPpI 170.6-173.7; HBal 21.1-21.8.

Type Material

de Andrade and Baroni Urbani (1999) - Worker, soldier and gyne. Type locality: Concepcion, Paraguay. Type material 26 workers, 18 soldiers, 10 gynes, all syntypes, labelled "Concepcion, Paraguay, in Agonandra brasiliensis, Chodat", in Musee d'Histoire Naturelle Genève, 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 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 364, male described)
  • Forel, A. 1921a [1920]. Fourmis trouvées dans des galles de Cordia et d'Agonandra, etc. Bull. Soc. Bot. Genève (2) 12: 201-208 (page 204, 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 221, Combination in Paracryptocerus)