Cephalotes curvistriatus

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Cephalotes curvistriatus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. curvistriatus
Binomial name
Cephalotes curvistriatus
(Forel, 1899)

Cephalotes curvistriatus P inbiocri002281724.jpg

Cephalotes curvistriatus D inbiocri002281724.jpg

Specimen Label

Specimens have been collected in a number of wet/moist forest habitat. Little else is known about the biology of Cephalotes curvistriatus.

Identification

A member of the texanus clade differing from its nearest outgroup species, Cephalotes texanus, in the worker by the thick, regular striae on the ventral part of the head, and from the closest ingroup species, Cephalotes lenca and Cephalotes sobrius, by the hind femora not angulate. The soldier differs from texanus by the foveae on the disc sparser and from that of sobrius Italic textfor the foveae on the disc denser. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Costa Rica (type locality), Mexico.

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.

  • curvistriatus. Cryptocerus curvistriatus Forel, 1899c: 52 (w.) COSTA RICA. Kempf, 1958a: 115 (s.q.m.). Combination in Paracryptocerus (Harnedia): Kempf, 1958a: 114; in Zacryptocerus: Hespenheide, 1986: 395; in Cephalotes: De Andrade & Baroni Urbani, 1999: 593.

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

Description

Worker

Kempf (1958) - Total length 4.2-4.8 mm; maximum length of head 1.18-1.36 mm; maximum length of thorax 1.21-1.43 mm. Black; the following ferruginous: tip of mandibles, tip of scape, basal funicular segment, tip of apical funicular segment, tarsites II-V; testaceous: frontal carinae, tip of femora, extensor face of tibiae, maculae of gaster, tip of thoracic teeth and peduncular spines.

Head opaque, subquadrate, maximum length of head subequal to, often slightly exceeding, the interocular width. Clypeal sutures vestigial. Lateral border of head sinuous in front of, upturned above eyes. Occipital lobes broadly obliquely truncate. Occipital border emarginate. Head gently convex above. Dorsum of head finely reticulate-punctate, rather densely foveolate, or even reticulate foveolate. Lower face of head regularly and coarsely longitudinally striate.

Thorax opaque. Anterior border arched in the middle, concave at the sides. Scapular angle incorporated in the lateral, tridentate border of pronotum. The two anteriormost teeth closer together, triangular, acute, somewhat foliaceous, the posterior tooth on the posterior corner either subrectangular or pointed, in the latter case pointing obliquely caudad. Promesonotal suture vestigial or obsolete, indicated at most by the lack of scalelike hair. Mesonotum with a very small denticle on each side, practically unarmed. Mesoepinotal suture as promesonotal suture, absent or marked merely by a lack of scalelike hair. Lateral border of basal face tridentate, the anterior two teeth very distinct, the second largest, the third tooth, on the junction of the declivous face, minute. Dorsum of thorax coarsely and longitudinally striatorugose, reticulate-rugose in front, near the anterior border of pronotum. Declivous face neither excavate, nor distinctly marginate on its borders, but longitudinally striate. Pleura horizontally striato-rugose. Outer face of fore femora longitudinally or obliquely striatorugose.

Peduncular segments opaque, sculptured as dorsum of thorax, except for the lower face which is longitudinally striate. Petiole with a vertically truncate, finely reticulate-punctate, anterior face, which terminates above on each side with a projecting small denticle. Lateral processes spinelike, their apices gently curved, and acute. Postpetiole broader than petiole, its dorsum gently convex, its lateral spines very long, their apices more, but never strongly, recurved.

Gaster opaque, oval, emarginate anteromesially. The broad, scarcely prominent anterolateral lobes with a hyaline, narrow crest on their border, which extends backwards to the level of the stigma.

Lateral border of gaster bluntly marginate beyond the anterior half of first tergite. Dorsum of gaster finely reticulate, with larger, mostly longitudinal, yet occasionally anastomosing rugosities, much finer than on thorax. First sternite smooth and shiny distally, longitudinally striate laterad, the striae converging behind in front of the posterior border forming concentric arches.

Standing hair on tip of gaster, anterolaterally and above the eyes on the lateral border of head. Scalelike hair canaliculate, silvery, appressed, highly shiny, in foveolae of head, between the costae of thorax, and on dorsum of peduncle and gaster, and on extensor face of femora and tibiae. Usually simple, always smaller on sides of legs, on lower face of head, and on first gastral sternite.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 4.28-5.04; HL 1.04-1.20; HW 1.16-1.36; EL 0.28-0.30; PW 1.04-1.20; PeW 0.58-0.64; PpW 0.74-0.69; HBaL 0.40-0.51; HBaW 0.09-0.12; CI 110.0-113.3; PI 111.5-117.8; PPeI 179.3-187.5; PPpI 150.7-157.9; HBal 22.5-25.0.

Soldier

Kempf (1958) - Total length 5.3-6.1 mm; maximum length of head 1.57-1.82 mm; maximum length of thorax 1.43-1.61 mm. Black; the following ferruginous: mandibles except chewing border, first funicular segment, apex of ultimate funicular segment, tarsites II-V; yellowish-brown: anterolateral portions of cephalic disc, tip of femora, extensor face of tibiae, gastral maculae.

Head somewhat shiny, surmounted by a subcircular, excavate disc, the floor of which is rather flat, the sides of which are strongly raised, concealing the floor of the disc, when head is seen in profile.

The lateral border of the cephalic disc, somewhat behind the eyes, curves abruptly more strongly mesad, forming an obtuse angle and joining the concave or convex occipital border at another angle, which is occasionally drawn out in the form of a very blunt tooth. Clypeal sutures vestigial. Floor of disc semitransparent above the antennal scrobe. Occipital lobes forming a more or less rounded corner, their posterior border strongly marginate. Floor of disc, sides of head and occiput finely yet superficially reticulate-punctate, covered with dense, somewhat larger, squamiferous foveolae, the intervals between the pits usually not exceeding, generally less than, the diameter of the pits. Lower face of head superficially reticulate, highly shining, sparsely foveolate.

Thorax subopaque. Anterior border arched mesially, slightly excised laterally; the anterior corner strongly dentate; the lateral border between this tooth and the strongly crested, raised, mesially broadly and shallowly interrupted transverse carina, is excised; following the carina strongly converging mesad, nearly straight. Promesonotal suture distinct. Mesonotum with a rounded or subangulate lobe on each side. Mesoepinotal suture impressed. Anterior corner of basal face of epinotum subdentate, followed posteriorly by a narrow, deep notch, and behind this notch a rather small, yet acute, tooth pointing obliquely cephalad, the posterior corner unarmed. Declivous face scarcely excavate discad, finely reticulate-punctate, with a few sparse longitudinal rugosities on its upper half, its lateral border marginate. Dorsum of thorax sculptured as head disc, except on the anteromesial portion of the basal face of epinotum where a few strong but very short longitudinal rugae are apparent. Sides of thorax opaque, finely reticulate-punctate, with occasional, rather irregular, rugosities. Fore coxae somewhat striate on the outer face. Femora fusiform.

Peduncular segments as in worker, but lacking the strong rugosities on dorsum, and the petiole small denticles on the upper border of the anterior face. Gaster similar to that of worker, the anterolateral hyaline crest very narrow or vestigial, not reaching back to the stigma of the first tergite. Longitudinal rugosities on first tergite very prominent on anterior third. Conversely the lateral rugosities or striae of the first sternite do not all, or just a few, converge concentrically and fuse mesially in front of the posterior border. Standing hair as in worker, a row of rather prominent setae around the border of the cephalic disc, reaching to backward beyond the eye, also a few laterally on the occipital lobe. Scalelike hair silvery, decumbent, in foveolae of head, thorax, peduncle. Cheeks and lower half of pleura very densely scaled. Scalelike hair small and very sparse on gaster, also sparse on lower face of head, sides of legs, and first sternite.

de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 5.36-6.20; HL 1.40-1.62; HW 1.60-1.76; EL 0.32-0.36; PW 1.52-1.64; PeW 0.68; PpW 0.72-0.76; HBaL 0.48-0.52; HBaW 0.12-0.13; CI 108.6-114.3; PI 105.3-107.3; PPeI 223.5-241.2; PPpI 211.1-215.8; HBaI 25.0.

Queen

de Andrade and Baroni Urbani (1999) - Total length 7.2-7.5 mm; maximum length of head 1.75-1.78 mm; maximum length of thorax 2.10-2.14 mm. In general resembling the soldier, with the differences of the caste and the following noteworthy features.

Posterior third of cephalic disc not excavate, but slightly convex; the lateral borders not raised. Posterior pair of ocelli very close to the occipital border. Transverse pronotal crest sharply marginate, not as prominent as in soldier, broadly interrupted mesially, not quite attaining the lateral border of pronotum. Lateral border of basal face of epinotum with a blunt triangular lobe, and a similar very short tooth on the posterior corner. Lateral processes of peduncular segments very short, the postpetiole, as seen in profile, strongly convex above. Gaster relatively short and broad. Outer face of fore coxae with a few vestigial, oblique rugosities. First gastral sternite mostly smooth, finely striato-rugose anterolaterally, the striae not converging behind in front of the posterior border. Wings slightly infumated. Fore wing extending backwards slightly beyond the tip of the normally extended gaster, lacking a transverse cubital vein, the radial vein touching directly the cubital vein (r-m absent, according to the terminology of H. H. Ross).”

Wingsfore wings with R+Sc connected to a marked pterostigma. 2r marked, Rsf5 connected with R1. Distal parts of A, Cu-A1 and Mf4 almost absent. Hind wings with R, M, and distal half of M +CuA marked; proximal part of M +CuA and distal part of M and CuA vestigial to absent.

Measurements (in mm) and indices: TL 7.48-7.72; HL 1.60-1.64; HW 1.72; EL 0.36-0.37; PW 1.68; PeW 0.64-0.68; PpW 0.80; HBaL 0.60; HBaW 0.16; CI 104.9-107.5 PI 102.4; PPeI 247.0-262.5; PPpI 210.0; HBaI 26.7.

Male

de Andrade and Baroni Urbani (1999) - Head (eyes included, mandibles excluded) 1/3 broader than long; vertexal angles strongly convex in full face view. Ocelli protuberant on the vertex. Eyes broadly convex and placed in the middle of the sides of the head. Frontal carinae diverging backwards and almost reaching the posterior border of the eyes. Frons flat. Clypeus convex, its anterior third flat. Mandibles slender, without lateral carina and with two distinct apical teeth. Scapes thick, twice longer than the first funicular joint; remaining funicular joints thickening from the base to the apex.

Mesosoma. Pronotum in dorsal view broadening backwards. Mesonotum convex; median Mayrian carina and parapsidal furrows weakly impressed. Scutellum convex, its sides converging posteriorly. Propodeum with differentiate basal and declivous faces; basal face convex, its sides converging posteriorly.

Petiole as broad as the postpetiole; its dorsal face sloping into the concave anterior border; its sides convex anteriorly and converging posteriorly. Postpetiole slightly convex, with a pair of small denticles on the anterior half of its sides.

Gaster narrower than the mesosoma.

Wings as in the gyne.

Sculpture. Head with thin, irregular anastomosing rugosities and punctated. Mesonotum, propodeum, petiole and sides of the thorax superficially and minutely reticulate-punctate and with irregular to almost longitudinal rugosities. Pronotum, postpetiole, and first gastral tergite reticulate-punctate; the same type of sculpture but more superficial on the legs, on the remaining tergites and on the sternites. Sparse and shallow, foveae-like, depressions the thorax.

Pilosity. Body covered by long, thin, dense, suberect and subdecumbent hairs; first gastral tergite and sternite, and dorsal half of femora with the same type of hairs but decumbent and shorter. Funiculi densely covered by thin, short, decumbent hairs; similar but thinner, sparser and slightly longer hairs on the legs.

Colour: head, mesosoma and pedicel brown; antennae, gaster and legs light brown.

Measurements (in mm) and indices: TL 4.92-5.14; HL 0.74-0.78; HW 0.96-1.00; EL 0.39-0.40; PW 1.04-1.08; PeW 0.35-0.39; PpW 0.41-0.43; HBaL 0.52-0.54; HBaW 0.08-0.09; CI 128.2-129.7; PI 92.3-92.6; PPeI 276.9-297.1; PPpI 241.9-263.4; HBaI 15.4-16.7.

Type Material

Worker. Type locality: Turrialba, Costa Rica. Type material presumably lost; not found neither in Musee d'Histoire Naturelle Genève nor in Museo Civico di Storia Naturale, Genoa.

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 593, Combination in Cephalotes)
  • Forel, A. 1899d. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 25-56 (page 52, worker described)
  • Hespenheide, H.A. 1986. Mimicry of ants of the genus Zacryptocerus. J. N. Y. Entomol. Soc. 94: 394-408 (page 395, Combination in Zacryptocerus)
  • Kempf, W. W. 1958a. New studies of the ant tribe Cephalotini (Hym. Formicidae). Stud. Entomol. (n.s.) 1: 1-168 (page 115, soldier, queen, male described, page 114, Combination in Paracryptocerus (Harnedia))