Cephalotes decoloratus

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

MCZ ENT 21095 Cephalotes decoloratus hal.jpg

MCZ ENT 21095 Cephalotes decoloratus had.jpg

Holotype Specimen Label

Synonyms

Mann reported collecting the type material (Wheeler and Mann 1914) from "colonies (that) were nesting in hollow twigs…frequently also in bamboo." Specimens from the Dominican Republic were collected from dry forest just east of Pedernales.

Identification

A member of the pallens clade differing from its sister species Cephalotes pellans by the following characters: worker petiole with a pair of spines shorter than its length and gaster anteriorly with a pair of broad, round membranaceous borders; soldier and gyne with deeper and denser foveae on the head disc. (de Andrade and Baroni Urbani 1999)

Keys including this Species

Distribution

Southern Hispaniola.

Distribution based on Regional Taxon Lists

Neotropical Region: Dominican Republic, Greater Antilles, Haiti (type locality).

Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

In Jaragua National Park in Pedernales Province small colonies, or single nests of a larger colony, were found in various dead sticks suspended above the ground. The workers were not active during the time of day the nests were encountered. The single nest entrance is small, blocked by the head of the soldier, and very cryptic (Lubertazzi, April 2016).

Castes

Soldier
Worker

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • decoloratus. Cephalotes decoloratus De Andrade, in De Andrade & Baroni Urbani, 1999: 508. Replacement name, with new combination, revival from synonymy and elevation to species, for Cryptocerus varians subsp. marginata Wheeler, W.M. & Mann, 1914: 39. [Junior primary homonym of Cryptocerus marginatus Fabricius, 1804: 419.]
  • marginata. Cryptocerus varians subsp. marginata Wheeler, W.M. & Mann, 1914: 39, fig. 17 (s.w.q.) HAITI. [Junior primary homonym of Cryptocerus marginatus Fabricius, 1804: 419 (above).] Junior synonym of pallens: Kempf, 1958a: 151. Replacement name: decoloratus De Andrade, in De Andrade & Baroni Urbani, 1999: 508.

Description

From de Andrade and Baroni Urbani (1999): C. decoloratus is endemic from Hispaniola. This species had been previously described by WHEELER & MANN (1914) as a subspecies of Cephalotes varians using a preoccupied name.

Its sister species is Cephalotes pellans from S. Brazil. The characters distinguishing the two species and already listed in the diagnosis are constant among all 71 workers, 27 soldiers and 4 gynes we examined. This fact, together with the geographic distance between the two, leaves no doubt on the necessity to consider decoloratus as a good species.

The most significant variation observed in decoloratus is in the soldiers from Bani: these soldiers have the floor of the disc with foveae shallower and sparser than those from Haiti.

Worker

From de Andrade and Baroni Urbani (1999) - Head broader than long. Vertexal angles with a pair of narrow, round membranaceous expansions.

Mesosoma. Scapular angles not visible in dorsal view. Anterior pronotal border convex. Pronotum with a pair of broad membranaceous expansions gently converging posteriorly. Promesonotal suture variably impressed. Mesonotal sides with a pair of triangular semimembranaceous teeth followed or not by a pair of minute denticles. Propodeum with poorly differentiated basal and declivous faces. Membranaceous expansions of the propodeum with one or, rarely, two pairs of superficial incisions. Margin of the propodeal expansions minutely crenulate.

Petiole with the anterior face truncate and medially slightly concave. Petiolar sides with triangular, pointed spines. Postpetiole convex dorsally; its sides with pointed or round spines directed forwards at the base.

Gaster suboval, not strongly protruding anteriorly and with a pair of round, membranaceous expansions surpassing the stigma posteriorly and continuing backwards up to the posterior border as a thin margin.

Mid and hind femora gently angulate and crested; the crest narrower on the mid femora. Mid and hind basitarsi flat, with the proximal part broader than the distal one.

Sculpture. Head dorsum, mesosoma and pedicel minutely reticulate and with dense foveae; the foveae deeper on the posterior third of the head, shallower, smaller and irregular on the anterior third, sparserand superimposed to short, thin, irregular rugosities on the frontal carinae and very small on the pedicel. Ventral part of the head posteriorly reticulate; this sculpture more superficial and superimposed to foveae and longitudinal rugosities on the remaining ventral surface. Pleurae reticulate and with thin, faint longitudinal rugosities on the propleurae. First gastral tergite reticulate and with sparse, superficial foveae larger on the anterior third and on the sides; thin, superficial, irregular rugosites superimposed to this sculpture. First gastral sternite with sculpture similar to the one on the corresponding tergite but less impressed. Center of the first gastral sternite superficially shining. Legs reticulate with sparse, small, very superficial and slightly irregular foveae, denser on the outer face of the tibiae.

Pilosity. Each fovea with an appressed hair. Sides of the vertexal angles, posterior borders of the gastral tergites and sternites, and legs with rare clubbed hairs; similar hairs but thinner and denser on the first gastral sternite. Parts of the gaster and legs without foveae with short, appressed, very thin hairs. Gastral sternites with additional, rare, long, pointed hairs.

Colour. Brown to black with the membranaceous expansions of the body lighter.

Measurements (in mm) and indices: TL 4.50-4.72; HL 1.04-1.10; HW 1.28-1.34; EL 0.27-0.28; PW 1.06-1.14; PeW 0.73-0.78; PpW 0.65-0.70; HBaL 0.31-0.33; HBaW 0.13-0.14; CI 121.8-123.1; PI 117.5-120.7; PPeI 145.2-146.1; PPpI 162.8-163.1; HBaI 41.9-42.4.

Soldier

From de Andrade and Baroni Urbani (1999) - Head disc suboval with strongly raised sides. Floor of the disc weakly convex medially. Vertex superficially impressed. Vertexal angles completely separate from the disc, obtuse or pointed and with the margin variably crenulate. Eyes slightly convex and hidden by the disc. Mandibles laterally carinate.

Mesosoma. Humeral angles with a pair of obtuse teeth. Mesonotum with a pair of broad, truncate or obtuse teeth followed or not by a pair of minute denticles. Sides of the basal face of the propodeum with two pairs of round swellings or teeth followed by another pair of stout teeth curved up and forwards. Declivous face of the propodeum narrowing posteriorly.

Pedicel as in the worker but with narrower and shorter spines.

Hind femora gently angulate and strongly carinate.

Gaster. Oval and with a pair of protruding anterior lobes.

Sculpture. Head dorsum minutely punctate variably shining and with large, differently clumped foveae diminishing in size anteriorly, larger and deeper posteriorly. Few specimens have parts of the head covered by a thin layer of probably camouflage material. Sides of the disc densely and irregularly foveolate, the foveae more superficial on the anterior half. Ventral part of the head shining, punctate, irregularly foveolate-rugulose; the foveae and rugosities absent on the posterior sides. Mesosoma minutely reticulate-punctate and with dense foveae, sparser on the pronotum and smaller on the propodeum. Pedicel with sculpture similar to the one on the propodeum but with smaller and less regular foveae. Pleurae reticulate. Propleurae with shallow foveae on the upper part; smaller specimens with the foveae sparser and superimposed to few transversal, thin rugosities. Gaster and legs with sculpture similar to the one of the worker but with slightly larger foveae.

Pilosity. Each fovea with an appressed hair. External border of the disc and sides of the head with few, sub erect, long, clavate hairs, absent on the anterior border of the disc. Internal border of the disc with one or two rows of long, appressed hairs. Vertexal angles and posterior border of the gastral segments with clubbed hairs, rare and shorter on the vertexal angles; First gastral sternite with rarc, thin clubbed hairs. Parts of the gaster and legs without foveae with short, appressed hairs. Gastral sternites with additional, rare, long, pointed hairs.

Colour. Dark brown to black with slightly lighter gaster.

Measurements (in mm) and indices: TL 6.52-7.66; HL 1.80-2.16; HW 1.72-2.00; EL 0.35-0.36; PW 1.62-1.84; PeW 0.77-0.86; Pp W 0.69-0.79; HBaL 0.30-0.36; HBa W 0.1 'i-O.17; CI 92.6-95.5; PI 106.2-108.7; PPeI 210.4-213.9; PPpI 232.9-234.8; HBaI 47.2-50.0.

Queen

From de Andrade and Baroni Urbani (1999) - Differing from the soldier in the following characters. Sides of the disc with lower border. Floor of the disc flat. Posterior part of the disc superficially depressed. Humeral angles obtuse. Pronotal crest less marked. Pronotum, mesonotum and scutellum flat in side view. Sides of the basal face of the propodcum anteriorly convex and posteriorly with a pair of broad, obtuse teeth separate by a deep, marked incision. Anterior face of the petiole more oblique. Petiolar sides with a pair of minute denticles. Postpetiole as in the soldier but with the spines broader, shorter and slightly more pointed. Gaster as in the soldier but much longer. Legs as in the soldier but with less salient carinae on the outer face of the femora.

Sculpture. Foveae deeper and denser on the head dorsum, larger and shallower on the mesosoma, sparse, superficial on the propleurae, small, dense, and deep on the upper and anterior half of the lower mesopleurae.

Pilosity. As in the soldier.

Colour. Apparently brown but all specimens available are immature.

Measurements (in mm) and indices: TL 8.32-8.36; HL 1.80; HW 1.60; EL 0.42-0.44; PW 1.54-1.52; PeW 0.67-0.71; PpW 0.76-0.77; HBaL 0.49-0.48; HBaW 0.20; CI 88.8; PI 103.9-105.3; PPeI 214.1-229.8; PPpI 197.4-202.6; HBaI 40.8--41.7.

Type Material

1 worker and 2 soldiers labelled as lectotype by Kempf and 3 additional workers labelled as paratype Museu de Zoologia da Universidade de Sao Paulo, 1 soldier and 1 worker Musee d'Histoire Naturelle Genève, 2 workers, 1 soldier Museo Civico di Storia Naturale, Genoa, 2 workers and 1 soldier Museum of Comparative Zoology, 3 workers Naturhistorisches Museum Basel, 10 workers, 5 soldiers National Museum of Natural History; additional original type material from Manneville (Haiti), 2 workers and 1 soldier Museum of Comparative Zoology, 3 workers Musee d'Histoire Naturelle Genève, 4 workers and 2 soldiers Naturhistorisches Museum Basel, 2 workers and 1 soldier Museu de Zoologia da Universidade de Sao Paulo; additional type material from Petionville (Haiti), 2 workers, 1 soldier Museu de Zoologia da Universidade de Sao Paulo, 1 worker National Museum of Natural History, all examined.

Etymology

Derivatio nominis: in Latin decoloratus (= pale) is a synonym of pallens, the name of the species with which the present one 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 508, Replacement name, with new combination, revival from synonymy and elevation to species, for Cryptocerus varians subsp. marginata)
  • Wheeler, W. M.; Mann, W. M. 1914. The ants of Haiti. Bull. Am. Mus. Nat. Hist. 33: 1-61 (page 39, [Junior primary homonym of Cryptocerus marginatus Fabricius, 1804: 419.])