Cephalotes nilpiei

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Cephalotes nilpiei
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. nilpiei
Binomial name
Cephalotes nilpiei
De Andrade, 1999

De Andrade 1999 Cephalotes OCR - Copy-386 Cephalotes-nilpiei had.jpg

Nothing is known about the biology of Cephalotes nilpiei.

Identification

A member of the pinelii clade differing from its two closest in group species, Cephalotes pileini and Cephalotes pinelii, in the worker, by the propodeal suture more impressed, and, from the soldier pileini by the propodeum with a pair of teeth, and from the soldier pinelii by the shallower foveae on the head. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (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.

  • nilpiei. Cephalotes nilpiei De Andrade, in De Andrade & Baroni Urbani, 1999: 381, figs. 169, 170 (s.w.) BRAZIL.

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

Description

Worker

Head subquadrate with convex frons. Frontal carinae covering the mandibles proximally and upturned in front of the eyes; border of the frontal carinae strongly crenulate anteriorly and superficially crenulate laterally. Vertexal angles broad and round, with a thin margin converging before the middle of the vertexal border. Vertexal border medially concave. Mandibles with thick lateral carina.

Mesosoma gently convex. Scapular angles absent or not visible in dorsal view. Pronotum anteriorly convex in dorsal view; pronotal sides with a membranaceous expansion anteriorly obtuse or round and narrowing posteriorly. Promesonotal suture, in dorsal view, superficially impressed. Mesonotum with a pair of thin, pointed, membranaceous teeth. Propodeal suture deeply impressed. Declivous face of the propodeum gently sloping backwards. Basal and declivous propodeal faces with a membranaceous lateral expansion originating from the propodeal suture.

Anterior face of the petiole medially slightly concave; dorsal face gently convex. Sides of the petiole with a wing-shaped, membranaceous expansion with round tip and directed laterally. Postpetiole convex dorsally; postpetiolar sides with a broad wing-shaped, membranaceous expansion with truncate tip.

Gaster suboval. First gastral tergite anterolaterally with a broad membranaceous expansion.

Legs. Mid and hind femora dorsally angulatc and with a thin carina on the distal part of their dorsum. Mid and hind basitarsi compressed at the base.

Sculpture. Head dorsum reticulate, with dense, superficial, irregular foveae diminishing in size anteriorly. Frontal carinae reticulate and with sparse, shallow foveae. Ventral face of the head reticulate, with superficial, sparse foveae superimposed by thin, longitudinal rugosities more impressed on the sides. Mesosoma and pedicel with the same sculpture as on the head dorsum but the rugosities more impressed and regular on the pronotum and mesonotum. Declivous face of the propodeum reticulate and superficially rugulose. Gaster and legs reticulate. Pleurae reticulate and with longitudinal rugosities on the propleurae and anterior half of the mesopleurae.

Pilosity. Each fovea with an appressed, thick hair; similar hairs but not originating from the foveae on the membranaceous expansions, on the gaster and on the legs. External part of the frontal carinae, dorsum of the first gastral segments and posterior border of the remaining gastral segments with erect, clubbed hairs, longer on the posterior border and rare on the dorsum. Posterior border of the gastral sternites with few, long, thin, pointed hairs.

Colour. Dark brown with lighter tibiae and distal parts of the femora. Frontal carinae orange and semi-transparent. Membranaceous expansions of the body yellowish and semitransparent. First gastral tergite anterolaterally with an orange strip surpassing the first gastral stigma, in some specimens the strip prolonged posteriorly but less pigmented. Sides of the pronotum, propodeum and pedicel with a thin, orange strip.

Measurements (in mm) and indices: TL 4.04-4.64; HL 1.00-1.16; HW 1.16-1.32; EL 0.24-0.28; PW 1.00-1.16; PeW 0.58-0.63; PpW 0.60-0.63; HBaL 0.36-0.38; HBaW 0.13-0.14; CI 113.8-116.0; PI 113.8-116.0; PPeI 172.4-184.1; PPpI 166.7-184.1; HBaI 36.1-36.8.

Soldier

Head disc subquadrate, with differentiated border, raised and with crenulations more impressed anteriorly. Sides of the disc not covering completely the eyes and broadening anteriorly. Floor of the disc concave and little convex in the middle. Vertexal angles subrounded, completely separate from the disc and with superficially crenulate border. Mandibles laterally carinate and laterally hidden by the frontal carinae.

Mesosoma. Anterior pronotal border convex. Humeral angles with an obtuse, lateral, membranaceous expansion converging posteriorly up to the middle of the pronotum where it continues into the pronotal carina. Pronotal carina high, separate in the middle by an incision, each half posteriorly convex and diminishing in height towards the middle of the pronotum. Posterior half of the pronotal sides strongly converging posteriorly. Pronotal suture impressed in dorsal view. Promesonotal suture deeply impressed. Mesonotal sides with a pair of broad, obtuse teeth followed by a pair of vestigial, thin, minute denticles. Propodeum with differentiate basal and declivous faces; sides of the basal face forming cranially a pair of obtuse expansions directed anteriorly and followed by a convex, narrow, membranaceous expansion converging posteriorly into a pair of denticles curved upwards. Declivous face of the propodeum narrowing posteriorly and with a broad, membranaceous expansion.

Pedicel, legs and gaster as in the worker but with the membranaceous expansions less broad.

Sculpture. Head dorsum superficially reticulate, slightly shining and with foveae; the foveae contiguous posteriorly diminishing in size and more superficial anteriorly. Ventral face of the head reticulate and with thin, longitudinal rugosities; the two anterior thirds of the ventral face of the head with superficial, irregular foveae. Mesosoma reticulate and with dense foveae, smaller and irregular on the basal face of the propodeum. Pedicel with the same sculpture as the mesosoma but with smaller and shallower foveae. Declivous face of the propodeum, gaster and legs reticulate. Pleurae reticulate and with longitudinal rugosities on the propleurae only.

Pilosity. As in the worker but with the clubbed hairs also on the mesosoma.

Colour. Black with lighter tibiae and distal part of the femora. Frontal carinae orange and semi-transparent. Membranaceous expansions of the body yellowish and semi-transparent. First gastral tergite anterolaterally with an orange spot surpassing the first gastral stigma posteriorly, another spot but lighter before the posterior border. Sides of the pronotum, propodeum and pedicel with an orange strip.

Measurements (in mm) and indices: TL 5.40-5.68; HL 1.36-1.40; HW 1.48; EL 0.30-0.31; PW 1.40-1.48; PeW 0.61-0.63; PpW 0.62-0.64; HBaL 0.40-0.42; HBaW 0.15-0.16; CI 105.7-108.8; PI 100.0-105.7; PPeI 222.2-242.6; PPpI 218.7-238.7; HBaI 37.5-38.1.

Type Material

Holotype: worker, Brazil, Rio de Janeiro, Parque Nacional de Itatiaia, 15.XII.1966, 950-1000 m, H. Reichardt Museu de Zoologia da Universidade de Sao Paulo. Paratypes: 9 workers and 2 soldiers, same data as the holotype MZSP.

Etymology

Nilpiei is an anagram of pinelii, the name of the species with which the new species had been previously confused.

References

  • De Andrade, M. L.; Baroni Urbani, C. 1999. Diversity and adaptation in the ant genus Cephalotes, past and present. Stuttg. Beitr. Naturk. Ser. B (Geol. Paläontol.) 271: 1-889 (page 381, figs. 169, 170 soldier, worker described)