Cephalotes wheeleri

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Cephalotes wheeleri
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. wheeleri
Binomial name
Cephalotes wheeleri
(Forel, 1901)

Cephalotes wheeleri P casent0904914.jpg

Cephalotes wheeleri D casent0904914.jpg

Specimen Label

Besides knowing that a collection of this species was made in tropical semideciduous forest, nothing is known about the biology of Cephalotes wheeleri.

Identification

A member of the wheeleri clade differing from its sister species, Cephalotes toltecus, in the worker by the genal area and the mesosoma with more regular longitudinal rugosities, and, in the soldier, by the disc with sparser foveae and without short, broad, medial tumulus. Soldiers of wheeleri and toltecus can be distinguished from the other soldiers of the wheeleri clade by the floor of the disc flat posteriorly. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Mexico (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.

  • wheeleri. Cryptocerus wheeleri Forel, 1901c: 126 (s.w.) MEXICO. De Andrade & Baroni Urbani, 1999: 578 (m.); Wheeler, G.C. & Wheeler, J. 1954b: 157 (l.). Combination in Paracryptocerus (Harnedia): Kempf, 1958a: 132; in Zacryptocerus: Hespenheide, 1986: 395; in Cephalotes: De Andrade & Baroni Urbani, 1999: 574.

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) - Vertexal angles rounded, with superficially crenulate borders. Occiput almost straight. Postoccipital suture open antero-ventrally. Cheeks not marginate. Frontal carinae with a notch over the eyes. Antennal scrobes reaching the antero-ventral border of the eyes posteriorly. Anterior clypeal border concave. Mandibles laterally superficially carinate.

Mesosoma convex in side view. Pronotum in dorsal view with the anterior border convex. Scapular angles absent or not visible in dorsal view. Pronotal sides with narrow lamellae bearing three teeth. Humeral angles with a short, pointed, lateral teeth slightly bent anteriorly, followed by another tooth of the same size or smaller than the first and variably pointed, and by a third broad and obtuse tooth. Sides of the mesonotum converging and unarmed. Promesonotal and propodeal sutures superficially marked in some specimens, better visible on the sides. Propodeum declivous, without distinct, differentiate, basal and declivous faces, with a pointed, thin spine at the end of its first half, directed laterally and slightly upwards.

Petiole anteriorly truncate; its anterior border marked by a transversal carina variably impressed. Petiolar spines half of the length of the petiole, thin, pointed backwards and placed on the middle of the petiolar sides. Postpetiole broader than petiole, with thin, pointed spines arising anterolaterally and curved backwards at the base.

Gaster oval, without crest or lateral margin.

Hind and mid femora neither angulate nor denticulate; mid and hind basitarsi long and without flat and broad base.

Sculpture. Head dorsum reticulate and with superficial, slightly irregular foveae sometimes sparser behind the clypeus, denser on the vertexal angles. Frontal carinae superficially punctate. Ventral face of the head and sides of the mesosoma striato-rugose, superficially reticulate, slightly shining. Mesosoma and pedicel minutely reticulate, striato-rugose and with few, irregular foveae. Gaster superficially reticulate and shining. First gastral tergite with longitudinal rugulations originating from the articulation with the postpetiole and diverging backwards. First sternite with longitudinal rugulations on the sides only. Legs minutely reticulate-punctate, with slightly shining femora. Distal part of the mid and hind femora and outer face of the tibiae with irregular, superficial foveae and rugosities.

Pilosity. Body with three types of sparse hairs: (1) long, erect, truncate, on the mesosoma, on the pedicel and gaster, slightly shorter on the head dorsum; (2) appressed and thick, denser on the occipital borders, on the dorsal sides of the mesosoma and on the pedicel, shorter and thinner on the frons, on the middle of the mesosoma and posterior border of the first gastral tergite and legs; (3) minute and thin on the gaster and on the legs.

Colour. Dark brown to black, with yellowish frontal carinae, reddish-brown antennae and femora, lighter tibiae, tarsi, propodeal and peduncular spines.

Measurements (in mm) and indices: TL 3.84-4.28; HL 0.92-1.04; HW 1.04-1.20; EL 0.28; PW 0.84-0.98; PeW 0.48-0.56; PpW 0.56-0.60; HBaL 0.40-0.48; HBaW 0.08-0.09; CI 113.0-115.4; PI 122.4-123.8; PPeI 175.0; PPpI 150.0-163.3; HBaI 18.7-20.0.

Soldier

de Andrade and Baroni Urbani (1999) - Head disc present. Head dorsum with the anterior third declivous and concave on its sides, the rest flat and slightly lower than the borders of the disc. Frontal carinae broadly expanded anteriorly, converging posteriorly and connected by a convex carina on the vertex. Vertexal border round and marginate on the sides. Eyes moderately flat and not hidden by the disc. Clypeal border deeply concave anteriorly. Mandibles laterally carinate and partially hidden by the frontal carinae.

Mesosoma. Humeral angles with a broad, obtuse tooth anteriorly, their sides converging posteriorly. Pronotal carina marked on the sides but discontinuous in the middle. Promesonotal suture impressed. Mesonotal sides with a broad tooth with pointed tip, rarely obtuse. Lower mesopleurae without denticles. Propodeum differentiated in basal and declivous faces; basal face slightly convex dorsally, with a pointed tooth in the middle of each side and converging posteriorly to the declivous face; declivous face concave in the middle.

Petiole with distinctly differentiated anterior and posterior faces; anterior face vertical, posterior face slightly convex and bearing a pointed spine directed backwards on the sides. Postpetiole broadly convex; petiolar spines arising from the anterior border of the petiole and little curved.

Gaster laterally not marginate, simply with a little protruding anterior border.

Legs. Fore coxae with a tumulus anteriorly. Mid and hind femora without angle or denticles. Mid and hind basitarsi without broad base and not compressed laterally.

Sculpture. Head, mesosoma and pedicel superficially and minutely reticulate-punctate, the reticulation absent on the head dorsum, covered by deep foveae, broader than their interspaces on the two posterior thirds of the head, less impressed on the frontal carinae, on the declivous part of the vertex, on the two anterior thirds of the ventral part of the head, on the pronotum, on the sides of the mesonotum and on the basal face of the propodeum; the same structure sparser on the propleurae, on the middle of the mesonotum and on the basal face of the propodeum; first dorsal third of the head with foveae smaller than those on the two posterior thirds and almost as broad as their interspaces; the foveae oval and shallower on the pedicel. Posterior third of the ventral part of the head, legs, sides of the first gastral tergite, posterior half of the first gastral sternite superficially reticulate-punctate and shining, this sculpture is more impressed on the posterior half of the first tergite and anterior half of the first sternite. Declivous face of the propodeum, meta- and propleurae, anterior half of the first gastral tergite reticulate-punctate and with more or less longitudinal rugulosities. The rugae on the first gastral sternite sometimes are present only on the anterior third of it, or surpassing its first half, and slightly curved to the sides. Outer face of the tibiae with oval and superficial foveae.

Pilosity. Body with three types of hairs: (1) rare, long, erect, truncate on the mesosoma, pedicel and dorsum of the first gastral tergite, sparser on the legs and apex of the gaster, and shorter on the first gastral sternite; (2) decumbent to appressed on each fovea, sparse on the legs, longer and thicker on the pedicel and on the ventral part of the meso- and metapleurae; (3) minute and thin on the gaster.

Colour. Dark brown to black, with reddish-brown frontal carinae, antennae, femora, and lighter tarsi.

Measurements (in mm) and indices: TL 6.04-6.52; HL 1.52-1.56; HW 1.68-1.72; EL 0.36; PW 1.64-1.68; PeW 0.64; PpW 0.68-0.72; HBaL 0.44-0.46; HBaW 0.10-0.11; CI 110.2-110.5; PI 102.4; PPeI 256.2-262.5; PPpI 227.7-247.0; HBaI 22.7-23.9.

Male

de Andrade and Baroni Urbani (1999) - Head, eyes included, almost 1/3 broader than long; vertexal angles convex. Frontal carinae not raised, strongly diverging backwards and not reaching the first ocellus. Clypeus convex, its anterior border straight. Scapes thick, twice as long as the first funicular joint; remaining funicular joints thickening from the base to the apex.

Mesosoma. Mayrian furrows impressed. Propodeum with differentiate basal and declivous faces; basal face convex dorsally and with the sides converging posteriorly; declivous face converging posteriorly and laterally marginate.

Petiole with the anterior face truncate and concave medially; petiole and postpetiole convex dorsally and laterally.

Gaster longer than the mesosoma.

Sculpture. Head and pronotum minutely punctate and with very broad, irregular reticulation. Mesonotum punctate and with superficial foveae surrounded by thin rugosities. Scutellum punctate and with thin, longitudinal rugosities. Basal face of the propodeum and pleurae punctate and with irregular, longitudinal rugosities. Declivous face of the propodeum and gaster superficially reticulate. Pedicel punctate and with thin, longitudinal rugosities slightly irregular on the sides. Legs punctate.

Pilosity. Body with long, pointed hairs, suberect on the head and mesosoma, decumbent on the propodeum, pedicel, gaster and legs.

Colour. The sole available immature specimen is light brown with lighter legs.

Measurements (in mm) and indices: TL 5.58; HL 0.76; HW 0.92; EL 0.39; PW (not measurable: deformed); PeW 0.43; PpW 0.49; HBaL 0.55; HBaW 0.08; CI 121.0; HBaI 14.5.

Note: The description above is based on a single immature and damaged male belonging to the wheeleri type series; we did not dare dissecting its genitalia. A few genital characters visible without dissection have been nonetheless included in the data matrix for this species.

Type Material

Syntype Specimen Labels

de Andrade and Baroni Urbani (1999) - Worker, soldier. Type locality: Cuernavaca (Morelos, Mexico). Type material: lectotype soldier in Museu de Zoologia da Universidade de Sao Paulo and several paralectotype workers and soldiers divided between the Museum of Comparative Zoology, Musee d'Histoire Naturelle Genève, MZSP, Museo Civico di Storia Naturale, Genoa and National Museum of Natural History (Kempf, 1958 a: 132), examined.

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 578, male described, page 574, Combination in Cephalotes)
  • Forel, A. 1901d. I. Fourmis mexicaines récoltées par M. le professeur W.-M. Wheeler. II. A propos de la classification des fourmis. Ann. Soc. Entomol. Belg. 45: 123-141 (page 126, soldier, 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 132, Combination in Paracryptocerus (Harnedia))
  • Wheeler, G. C.; Wheeler, J. 1954b. The ant larvae of the myrmicine tribes Cataulacini and Cephalotini. J. Wash. Acad. Sci. 44: 149-157 (page 157, larva described)