| Cephalotes biguttatus|
Nothing is known about the biology of Cephalotes biguttatus.
- 1 Identification
- 2 Distribution
- 3 Biology
- 4 Castes
- 5 Nomenclature
- 6 References
A member of the multispinosus clade differing from its outgroup species by the presence of gastral spots and from the two ingroups by the superficial sculpture of the worker and soldier, and, in the soldier only, by the absence of cephalic disc. (de Andrade and Baroni Urbani 1999)
Keys including this Species
Distribution based on Regional Taxon Lists
Distribution based on AntMaps
Distribution based on AntWeb specimens
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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.
The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.
- biguttatus. Cryptocerus gibbosus r. biguttatus Emery, 1890b: 73, pl. 9, fig. 3 (s.w.q.) COSTA RICA. [Also described as new by Emery, 1894k: 59.] Combination in Paracryptocerus: Kempf, 1951: 226; in Zacryptocerus: Kugler, C. 1978a: 474; in Cephalotes: Baroni Urbani, 1998: 326; De Andrade & Baroni Urbani, 1999: 303. Subspecies of multispinosus: Forel, 1899c: 50; Kempf, 1972a: 179. Raised to species: De Andrade & Baroni Urbani, 1999: 303.
Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.
Kempf (1951) - Differs from the typical form [= multispinosus] by the more sparsely foveolate upper surface of head, and thorax. The sides of head are somewhat converging anteriorly, not quite parallel. Mesoepinotal suture distinct. Epinotum bordered in its entire length by a continuous, converging caudad, semitransparent crest, the lower portion of the declivous face slightly impressed mesad. Laterotergite of pronotum finely reticulate-punctate, without longitudinal striae. Scales within the foveolae on head thorax and gaster more slender, longer, and silvery.
de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 5.52-6.52; HL 1.20-1.48; HW 1.52-1.68; EL 0.32-0.39; PW 1.40-1.76; PeW 0.76-0.88; PpW 0.83-1.00; HBaL 0.54-0.60; HBaW 0.17-0.18; CI 126.7-129.0; PI 106.8-111.1; PPeI 180.0-200.0; PPpI 156.5-176.0; HBaI 30.0-31.5.
Kempf (1951) - The soldier may be recognized by the finer sculpture on head and thorax, the foveolae are as sparse as in the worker. The teeth on the vertex have no lateral crest between the sides of the head. The occipital angles are slightly upturned in very large soldiers. Sides of mesonotum without a conspicuous, projecting, rounded lobe. Epinotum as in the worker.
de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 7.00-7.04; HL 1.60; HW 2.04-2.06; EL 0.40; PW 1.92; PeW 0.90-0.92; PpW 1.00-1.04; HBaL 0.60; HBaW 0.19-0.20; CI 127.5-128.7; PI 106.2-107.3; PPeI 208.7-213.3; PPpI 184.6-192.0; HBaI 31.7-33.3.
Kempf (1951) - Length 1 1 mm. General color as in soldier and worker. Head longer, about as long as wide, the sides somewhat converging anteriorly. Vertex with two blunt teeth, connected by a blunt transverse crest. Occipital angles crested, subreetangular. Occiput truncate mesad and slightly excavated. Upper surface of head rather smooth, sparsely covered with small foveolae, containing a simple, appressed hair. Anterior corner of thorax rectangular, slightly notched behind the corner. Pronotum and mesonotum subfulgid, sparsely foveolate. Epinotum sharply marginate laterad, the basal face subopaque and densely foveolate, the declivous face subopaque, somewhat excavated, not foveolate. Upper mesopleura bulging, densely foveolate, the intervals rather fulgid. Lower mesopleura with a blunt tooth. Posterior portion of the sides of the thorax finely shagreened and subopaque. Femora not angulate above. Sides of petiole slightly diverging caudad until the last third, where it is suddenly constricted, forming a small tooth. Postpetiole with a short, slightly recurved, stout lateral tooth. Both peduncular segments densely but rather shallowly foveolate above. Gaster not crested antero-Iaterad, emarginate antero-mesad, with a large yellow spot on each anterior corner. Integument finely shagreened. Appressed hair minute. Wings infumated, veins brunneous. Fore wing with a close appendiculate marginal cell, the transverse cubital vein short to obsolete, the transverse median vein bisects the median vein into two subequal halves, the 2nd abscissa more than three times as long as the transverse median vein.
de Andrade and Baroni Urbani (1999) - Measurements (in mm) and indices: TL 10.80-10.86; HL 1.92-1.96; HW 2.20-2.32; EL 0.44-0.48; PW 2.20-2.50; PeW 0.92-1.10; PpW 1.24-1.30; HBaL 0.72-0.77; HBaW 0.22-0.26; CI 112.2-122.9; PI 88.0-105.3; PPeI 227.3-239.1; PPpI 177.4-192.3; HBaI 30.5-33.8.
de Andrade and Baroni Urbani (1999) - Worker, soldier and gyne. Type locality: Jimenez (Costa Rica). Type material: 7 workers, 3 soldiers, 1 gyne (Syntypes) from Jimenez (Costa Rica) in Museo Civico di Storia Naturale, Genoa, examined, 1 possible syntype soldier without locality label in Naturhistorisches Museum Basel, examined, 2 syntype workers and soldiers labeled Costa Rica in Musee d'Histoire Naturelle Genève, examined.
- 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)
- 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 303, combination in Cephalotes, raised to species)
- 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, pl. 9, fig. 3 soldier, worker, queen described)
- Forel, A. 1899d. Formicidae. [part]. Biol. Cent.-Am. Hym. 3: 25-56 (page 50, Race/subspecies of multispinosus)
- Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 226, Combination in Paracryptocerus)
- Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 179, Race/subspecies of multispinosus)
- Kugler, C. 1978a. A comparative study of the myrmicine sting apparatus (Hymenoptera, Formicidae). Stud. Entomol. 20: 413-548 (page 474, Combination in Zacryptocerus)