At the time of Kempf's (1951) revision the genus Cephalotes was restricted to the species with the antennal scrobe extending above the eye and back to the vertex margin. In Andrade and Baroni Urbani the former Cephalotes is a monophyletic group with 4 relatively similar species. This group contains the largest species in the genus, and the large, spiny workers are a conspicuous element in lowland Neotropical rainforests. Kempf (1951:109) summarized the biology of C. atratus, and surmised that the biology of alfaroi and other related species would be similar. Kempf's summary is as follows:
C. atratus is usually found on large trees, running up and down within the crevices of the bark. I have once caught a few individuals on the bulbs of an orchid of the genus Cattleya, in Petropolis, near Rio de Janeiro. The species is xyloecete, establishing the nest within the cavities of dead or living trees. Forel (1899, 1912) relates how he himself discovered an immense nest of these ants within a large dead tree on the island of Trinidad. Through repeated knocking on the trunk, he was able to arouse them. As a consequence, the ants left the nest in great numbers and destroyed in a few moments the nest of a small polybiine wasp, not sparing its inhabitants. Prof. Bugnion and Santschi (Forel, 1912; Santschi, 1929) found a nest of the same species in a cavity of a living tree, of 40 cm. in diameter, not much above the ground, which was being attacked by a considerable number of Eciton (Nomamyrmex) crassicorne, a species of army ants. The majority of the Cephalotes atratus were inside the nest, some of them engaged in closing the entrance by placing their heads side on side, whereas a few others on the outside, were struggling with the invaders. Most probably the army ants were longing for the eggs and larvae of Cephalotes, since the heavy armor of the adults were invulnerable to their attacks.According to Mann (1916) "the species nests generally in hollowed branches of high trees, though one nest was in the hollowed trunk of a small tree. It is omnivorous in habit, frequenting garbage and eating even carrion. Some dead macaws which I placed in the woods as bait for carrion-feeding insects were continually covered by C. atratus, to the exclusion of other insects. It is diurnal, and a striking form as it walks slowly about on tree trunks and logs. The hard spiny armor is sufficient to protect it from any ordinary enemy."
Eidmann (1936) gives a detailed description of the nest of a young colony of C. atratus, found near Mendes, State of Rio de Janeiro, Brazil. Wheeler (1942) reports that he discovered the same species nesting in a large branch of a Cecropia sciadophylla var. decurrens Sn.
L. Richter (1945), in a paper on Colombian Membracidae, presents an interesting account of the relationship between this ant and Tragopa peruviana Funkhouser, a neotropical membracid. According to this writer's observations, C. atratus is always found in company with Tragopa peruviana, which lives on the large leaves of Isertia haenkeana and, less frequently, on Vismia angusta. It is suggested that the ants take advantage of the sugary secretions of Tragopa. The interesting fact, however, consists both in the constant association of the two insects, and also in a certain "convergent adaptation" of the membracid which in its general habitus resembles the color and the shape of the gaster of C. atratus.
Throughout the mainland Neotropics, from Panama to Argentina. Questionable records from Costa Rica, Belize.
Taxonomic history
[Misspelled as atratulus by Santschi, 1929d PDF: 301.].Latreille, 1802a PDF: 274 (q.); Spinola, 1851b: 47; Spinola, 1853: 63 (m.); Wheeler & Wheeler, 1954b PDF: 154 (l.).Combination in Cryptocerus: Latreille, 1803: 280; Fabricius, 1804 PDF: 418; Latreille, 1809 PDF: 132; Leach, 1815: 147.Combination in Cryptocerus (Cephalotes): Wheeler, 1916c PDF: 12.Combination in Cephalotes: Latreille, 1802b: 358; Emery, 1914b PDF: 39; Santschi, 1916e PDF: 381; Santschi, 1920f PDF: 148; Smith, 1949c PDF: 19.Status as species: Linnaeus, 1767 PDF: 965; De Geer, 1773 PDF: 609; Fabricius, 1775 PDF: 395; Fabricius, 1782: 493; Retzius, 1783 PDF: 76; Gmelin, 1790 PDF: 2803; Christ, 1791 PDF: 516; Olivier, 1792: 500; Fabricius, 1793 PDF: 363; Latreille, 1802a PDF: 272; Latreille, 1803: 280; Fabricius, 1804 PDF: 418; Gravenhorst, 1807 PDF: 287; Latreille, 1809 PDF: 132; Leach, 1815: 147; Latreille, 1817a: 526; Klug, 1824 PDF: 200; Lepeletier de Saint-Fargeau, 1835 PDF: 170; Guérin-Méneville, 1844a PDF: 426; Spinola, 1851b: 47; Spinola, 1853: 63; Smith, 1853 PDF: 215; Smith, 1858a PDF: 187; Mayr, 1862 PDF: 757; Smith, 1862b PDF: 35; Smith, 1862d PDF: 408; Roger, 1862c PDF: 291; Mayr, 1863a PDF: 405; Roger, 1863b PDF: 38; Mayr, 1865 PDF: 114; Emery, 1878a PDF: ix (in list); Mayr, 1884 PDF: 37; Emery, 1890b PDF: 68; Dalla Torre, 1893 PDF: 141; Emery, 1894f PDF: 4; Forel, 1895b PDF: 133; Forel, 1899b PDF: 48; Forel, 1899j: 273; Forel, 1901m PDF: 50; Wheeler, 1905c PDF: 128; Emery, 1906c PDF: 170; Forel, 1906d PDF: 235; Forel, 1907h PDF: 3; Wheeler, 1908a PDF: 144; Forel, 1909a PDF: 257, 266; Forel, 1912f PDF: 199; Bruch, 1914 PDF: 218; Emery, 1914b PDF: 39; Mann, 1916 PDF: 448; Wheeler, 1916c PDF: 12; Wheeler, 1916f PDF: 326; Crawley, 1916b PDF: 371; Santschi, 1916e PDF: 381; Luederwaldt, 1918 PDF: 40; Wheeler, 1918b PDF: 26; Santschi, 1920f PDF: 148; Forel, 1921b PDF: 134; Wheeler, 1922e PDF: 12; Wheeler, 1923a PDF: 4; Emery, 1924f PDF: 303; Wheeler, 1925a: 36; Borgmeier, 1927c PDF: 114; Borgmeier, 1934 PDF: 103; Menozzi, 1935b PDF: 197; Eidmann, 1936b PDF: 81; Santschi, 1939f PDF: 163; Wheeler, 1942 PDF: 207; Smith, 1949c PDF: 19; Kempf, 1951 PDF: 114 (redescription); Kempf, 1958a: 10; Kempf, 1961b PDF: 514; Kempf, 1970c PDF: 335; Kempf, 1972b PDF: 75; Zolessi et al., 1988: 4; Brandão, 1991 PDF: 337; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111 (redescription); Wild, 2007b PDF: 31; Bezděčková et al., 2015 PDF: 115; Sandoval-Gómez & Sánchez-Restrepo, 2019 PDF: 904.Senior synonym of Cephalotes atratus crassispina: Kempf, 1951 PDF: 115; Kempf, 1958a: 10; Kempf, 1972b PDF: 75; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111.Senior synonym of Cephalotes dubitatus: Smith, 1858a PDF: 188; Mayr, 1863a PDF: 405; Roger, 1863b PDF: 38; Mayr, 1865 PDF: 114; Dalla Torre, 1893 PDF: 141; Forel, 1899b PDF: 48; Emery, 1924f PDF: 304; Borgmeier, 1927c PDF: 114; Kempf, 1951 PDF: 115; Kempf, 1972b PDF: 75; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111.Senior synonym of Cephalotes atratus erectus: De Andrade & Baroni Urbani, 1999 PDF: 112.Senior synonym of Cephalotes atratus nitidiventris: Kempf, 1951 PDF: 115; Kempf, 1972b PDF: 75; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111.Senior synonym of Cephalotes quadridens: Retzius, 1783 PDF: 76; Latreille, 1802a PDF: 272; Fabricius, 1804 PDF: 419; Latreille, 1817a: 526; Klug, 1824 PDF: 200; Smith, 1853 PDF: 215; Smith, 1858a PDF: 188; Mayr, 1863a PDF: 405; Roger, 1863b PDF: 38; Mayr, 1865 PDF: 114; Dalla Torre, 1893 PDF: 141; Forel, 1895b PDF: 133; Forel, 1899b PDF: 48; Wheeler, 1908a PDF: 144; Emery, 1924f PDF: 303; Borgmeier, 1927c PDF: 114; Kempf, 1951 PDF: 115; Kempf, 1958a: 10; Kempf, 1972b PDF: 75; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111.Senior synonym of Cephalotes atratus rufiventris: Kempf, 1951 PDF: 115; Kempf, 1958a: 10; Kempf, 1972b PDF: 75; Bolton, 1995b: 140; De Andrade & Baroni Urbani, 1999 PDF: 111.Material of the unavailable name Cephalotes atratus quadridens dehnowi referred here by Kempf, 1951 PDF: 115; Kempf, 1972b PDF: 75; Bolton, 1995b: 140.[[ worker ]]. Longueur: 10 mm. Differe du type de l'espece et de la race par sa tete nettement plus longue que large, dont les bords (aretes frontales roussatres) convergent distinctement en avant, le bord anterieur etant plus etroit (c'est a dire les aretes frontales moins avancees devant) que le bord posterieur. Epines pronotales ayant elles-memes une dent vers leur milieu et aucune dent ni tubercule entre elles deux. Les longues epines epino- tales sont subverticales, presque deux fois longues comme la face basale de l'epinotum, tres divergentes, si rapprochees a leur base, que celle-ci, quoique peu elargie, est presque aussi large que leur intervalle. Tout le corps est mat, abdomen y compris.
Recu autrefois d'Amerique, sans indication plus exacte de localite.
Alto Paraguay, Alto Paraná , Boquerón , Caaguazú , Canindeyú , Central, Concepción , Cordillera, Itapúa , Ñeembucú , Paraguarí , Pte. Hayes, San Pedro, “Paraguay” (s. loc.) (ALWC, LACM, MCSN, MHNG, MZSP, NHMB, NHMW). Literature records: Caaguazú , Central, Cordillera, “Paraguay”(s. loc.) (de Andrade & Baroni-Urbani 1999, Emery 1896b, Forel 1906, Forel 1907d, Santschi 1920b).
Cephalotes atratus is a species of arboreal ant in the genus Cephalotes, a genus characterized by its odd shaped head. These ants are known as gliding ants because of their ability to "parachute" by steering their fall if they lose their footing.[2][3]
It is called kaka-sikikoko in the Kwaza language of Rondônia, Brazil.[4]
Cephalotes atratus is a large, mainly black ant; workers are 8 to 14 mm (0.3 to 0.6 in) in length and females 20 mm (0.8 in). Males are up to 14 mm (0.55 in) and have black heads and thoraxes, and dark reddish-brown gasters and limbs. The workers are spiny and heavily armoured with powerful mandibles for chewing through wood.[5]
This ant occurs in lowland tropical rainforests in South America where its range extends from Panama and Venezuela to Peru, Bolivia, Paraguay, Uruguay and northern Argentina. It is a common arboreal species and colonies are found in forested areas, parkland with isolated trees, and urban habitats.[1]
This ant usually builds its nest in a hollow in a large live or dead tree. A small entrance may lead to a complex of tunnels and chambers, all excavated by the ants. From the nest the workers emerge by day to forage on other parts of the tree, or cross to contiguous trees, and make use of the crevices in the bark as runways to descend to the ground where they also forage. Auxiliary nests may sometimes be found a little apart from the main colony.[5]
Cephalotes atratus is omnivorous and feeds on what it can find. A major part of the diet is the secretions produced by treehoppers. Ants on the ground collect insect remains from bird droppings,[5] and it will feed on carrion and garbage as well as attack other insects.[1] It does not seem to eat plant material.[5] The armouring is sufficiently heavy to prevent predation by similar sized attackers. In one instance, a troop of army ants Nomamyrmex esenbeckii was seen attacking a colony, and the C. atratus workers made a living wall to defend the entrance, aligning their heavily sclerotised heads to prevent the army ants from getting inside to attack their brood.[1][6]
This ant is the only known definitive host of the nematode Myrmeconema neotropicum. The ants bring infected bird faeces back to the colony to feed to their young. As the ant develops, the nematode also develops and moves to the gaster in the ant's abdomen. This is where the adult nematodes mate and the eggs begin to develop within the female nematode. These developing embryos are the cause of the red colour in infected ants' abdomens. Older ants are sent out to forage while the eggs in infected ants develop and cause the abdomen to become red and look similar to a berry. Frugivorous birds (a paratenic host) then eat the ant abdomen containing the eggs; the eggs are then expelled through the bird's faeces, continuing the parasite's lifecycle. [7]
Cephalotes atratus is a species of arboreal ant in the genus Cephalotes, a genus characterized by its odd shaped head. These ants are known as gliding ants because of their ability to "parachute" by steering their fall if they lose their footing.
