Ant web entry: Atta cephalotes

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Ant web entry: Atta cephalotes

Post by Acromyrmexbob » Wed Oct 09, 2019 11:33 am

Species: Atta cephalotes (Linnaeus, 1758) Valid name.
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Classification:Order: HymenopteraFamily: FormicidaeSubfamily: MyrmicinaeGenus: AttaSpecies: cephalotes
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Taxonomic History (provided by Barry Bolton, 2019)
Formica cephalotes Linnaeus, 1758 PDF: 581 (w.) SURINAM. Neotropic. AntCat AntWiki HOL
Taxonomic history

Olivier, 1792: 500 (q.m.); Wheeler, 1949 PDF: 677 (l.).
Combination in Atta: Fabricius, 1804 PDF: 421; in Oecodoma: Latreille, 1818a PDF: 224.
Senior synonym of Atta migratoria: Retzius, 1783 PDF: 76; of Atta grossa: Latreille, 1802b: 224; of Atta fervens: Smith, 1858a PDF: 180; of Atta visitatrix: Emery, 1892c PDF: 162; of Atta cephalotes integrior, Atta cephalotes isthmicola, Atta lutea, Atta cephalotes oaxaquensis, Atta cephalotes opaca, Atta cephalotes polita: Borgmeier, 1959b PDF: 340.

Atta cephalotes is the most widely distributed species of leaf cutting ant. It occurs from southernmost Mexico to Ecuador and Brazil, and from the Lesser Antilles as far north as Bardbados (Holldobler & Wilson, 1990). An apparently disjunct population occurs in the Atlantic Coastal Forests of Brazil (Solomon, 2007). The species is widely regarded as a significant pest on crops including citrus, coffee, cocoa and ornamentals (Cherrett, 1986; Cherrett & Peregrine, 1976). The ecological success and ubiquity of A. cephalotes is owed in large part to its broad niche tolerance with respect to both nesting habitats and diet breadth (Solomon, 2007). The species has evolved to specialize in forest gaps, and consequently thrives in disturbed habitats such as farms and plantations (Cherrett & Peregrine, 1976). Niche modeling suggests that the current range of A. cephalotes is limited by dispersal constraints rather than suitable habitat (Solomon, 2007), and could cause significant ecological and agricultural devastation should it become introduced elsewhere (Hlldobler & Wilson, 1990). Atta cephalotes is highly variable, both among castes of the same colony and across populations. Workers vary enormously in shape, color, sculpture and pubescence (Borgmeier, 1959).

Geographic regions (According to curated Geolocale/Taxon lists):
Americas: Barbados, Bolivia, Brazil, Colombia, Costa Rica, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, Trinidad and Tobago
Biogeographic regions (According to curated Bioregion/Taxon lists):
Nearctic, Neotropical

Distribution Notes:
Southernmost Mexico to Ecuador and Brazil, and from the Lesser Antilles as far north as Bardbados. An apparently disjunct population occurs in the Atlantic Coastal Forests of Brazil.

Occasionally intercepted at US Ports of Entry.

In Costa Rica (Jack Longino)
This is the most common species of Atta in Costa Rica and it is found throughout the country at mid to low elevations. It occurs in wet or dry forest habitats and prefers clearings and forest edges. In the lowlands it is most common in agricultural areas and young second growth forest but can also occur in mature closed-canopy forest. At higher elevations it is increasingly restricted to open, highly insolated areas. For example, in the Monteverde area large nests of A. cephalotes occur in pastures around the community, at about 1400m elevation, but not in adjacent forest. Residents observe that nests are becoming more abundant and occurring at ever higher elevations, perhaps related to increased development and climate change.
Atta cephalotes has subterranean refuse dumps where spent fungus substrate is deposited. This is in contrast to A. colombica, which has conspicuous refuse dumps on the surface.

Nuptial flights occur during predawn hours and are synchronized across colonies in a population. Massive emergences occur sporadically during the year. On mornings following nuptial flights trails and clearings are sprinkled with the large queens and males, most of them being eaten by ants and other predators.

Atta cephalotes vs. Atta sexdens
Atta cephalotes can be distinguished by the wooly hairs on the heads of major workers and the shinier integument caused by the lack of hexagonal microsculpture, and the lack of small teeth or dents on the head anterior to the posterolateral spines. The pronotal spines of A. cephalotes tend to be more curved than those of its congeners, but this is a highly variable character.

Atta cephalotes vs. Atta native to the United States
The majors of A. cephalotes are also distinguished from its two congeners native to the United States (A. mexicana and A. texana) by the presence of wooly hairs on the cephalic dorsum. The petiolar spiracles are visible from above in the two native species, but cannot be seen from above in A. cephalotes (Borgmeier, 1959).

Atta cephalotes vs. Acromyrmex
Atta cephalotes is distinguished from its close relatives in the genus Acromyrmex by the presence of only three long spines on the mesosomal dorsum, and the absence of tubercles on the mesosomal and gastric dorsum.

Diagnosis among introduced and commonly intercepted species
Antenna 11-segmented. Antennal club indistinct. Antennal insertions at least partly covered by frontal lobes. Antennal scrobe lacking. Antennal scapes not conspicuously short; easily extended beyond eye level. Posterolateral corners of head spinose; lacking pair of small teeth anterior to posterolateral spines. Head smooth and shiny, not covered by hexagonal microsculpture. Head of soldier appearing wooly, covered in abundant long fine overlapping hairs. Mandibles triangular. Waist 2-segmented. Petiole with a distinct and upright node. Postpetiole attached to lower surface of gaster. Dorsum of promesonotum with 2 pairs of spines or teeth. Propodeum armed with spines. First gastral tergite lacking numerous tubercles. Yellow to reddish brown.

Redescription translated from Borgmeier, 1959b: 340
The most complete description of the soldiers of this important kind of gave De Geer (1773). On the reproductives did Mayr (1865) and Emery (1890, 1913), important information, and the drawings of male genitalia in Emery (1913 8) are absolutely accurate. Among the new authors are concerned Goncalves (1942) and Borg Meier (1950) with the taxonomy of this kind is an actual description of all searches in the box recent literature in vain.

Type locality: Paramaribo, Suriname.

Workers. - Maxima (Paramaribo): 14 mm length with his head bowed. Head width 6, 1 mm. Occiput gently bulged in the middle. Occipital zaehne short, often reduced to tubercles. Occipital lobes thickened and rounded, the front on each side with long hair of woolly Bueschel. Forehead with 3 ocelli, the posterior small, sometimes absent. Eyes strongly convex. Thorax narrower than the head of many (width front 2.7 mm). Pronotum on each side at the lower edge with a curved spine. Mesonotum with 2 pairs of spines, the anterior with a broad base, often rounded up and the back short and sharp. Epinotaldornen straight, directed backwards and upwards. Petiole and postpetiole side recently with one tooth. Gaster: width 3.5 mm. Legs slender; hind tibiae 5 mm. Shiny little head forward. Occiput polished, naked, matt body. Face, thorax, pedicel and gaster with long woolly hair, sparse hair, protruding, hairy legs sticking out. Rusty brown color. - Media (Paramaribo): length 7 mm. Head width 2, 6 mm. Occiput bulged wide. Kapfflach in profile. Occipital spines slightly shorter than the eye. Front Mesonotal spines thin and long, curved forward, the back short and pointed. Epinotal spines too thin, slightly shorter than the mesonotal spines. Forehead with shiny ribbon on the center. Thorax shiny little. Gaster dull. Kapf, thorax and gaster with long hair and short protruding fitting Pubescenz. - Minima (Paramaribo) L. about 2 mm. Head without mandibles as long as breil Occipital spines very short or obsolete. Mesonotal thorns short, often missing the rear. Epinotal spines longer. Color yellow. Tegument something shiny. Prominent scattered hairs.

Females (Paramaribo). - Length 22 mm. Head width 5, 25ri1m. Occipital edge almost straight. Lies behind corners without head gear, at most with weak tubercles. Sides of the head behind the eyes convex, strongly convergent forward. Ocelli large. Eyes convex. Mandibles glossy, striped, teeth with blunt Apikalzahn and 8-9. Epinotum reinforced. Thorax length 10 mm. Gaster Br 8.5 mm. Tibia III 5.4 mm. Wing about 28 mm at the outer edge strongly browned. Matt. Head, thorax and gaster with fine golden pubescence fitting. Legs fitting coat or diagonally. Yellow rust stain.

Males (Paramaribo). - Length about 18 mm. Head (Borgm. 1950, Figure 47): width 2, 8 mm. Occipital zaehne obsolete. Front plate with teeth. Eyes strongly convex. Mandibles narrow, inner margin concave, irregularly toothed, pointed Apikalzahn. Scape too thin, 2, 6 mm, on the apical half slightly thickened. Wing about 25 mm, outer margin strongly browned. Genitalia (Fig. 10): Not Squamula dorsally fused in the middle, longer than wide; stipes articulated to the Squamula, not fused with it, abgestuzt apical hair long. Voisellen stabfoermig, in profile gently curved, apically obliquely truncated. Sagittae built complex, each side with an upright sharpened keel, which extends to the base, where it terminates in a spike, the keels slightly diverging apically, basally more strongly, laterally outside of it there is a curved hook. is occupied at its end and the back edge with tiny sharp teeth, on the ventral side of the Sagitta's in the middle line, two closely spaced keels, which are in profile convex and serrated saw-are (the teeth are kopfwaerts directed and curved), which two keels separated by a furrow that widens and forms the apical foramen, located above the foramen on each side a broad, flat, triangular teeth. Subgenital bulged apically. Head and thorax woolly, 1st Gaster short segment pubescent. Color yellow rust or rust-brown.

Geographical distribution. - Mexico (Veracruz), Central America, Ecuador, Columbia, Peru, Bolivia (Chapare up), Venezuela, Guyana, Brazil (Amazonas, Para, Rondonia, Maranhao, Pernambuco, Baia (up I1heus, Belmonte and Mucuri).

Discussion. - Atta colombica cephalotes is very close, as evidenced by the male genitalia and the form det average worker, but colombica differs in the following important points: 1) the head of the soldiers is totally different, much narrower, incised on occipital deep edge, 2) the soldier is practically naked, pubescent only very fine fitting, and 3) in the middle are the workers Occipital spines always longer than the eye (at shorter cephalotes), 4) the male genitalia is squamate the top as long as wide, 5) are the Sagittalhaken less curved and serrated edge on the back clearly. The females of both species are hardly distinguishable (by colombica are slightly smaller). The dark brown female from Colombia, Bolivia and Costa Rica can easily be confused sexdens, etc., but are identified by the absence of Occipital zaehne and the darkened edge of the wing.

Variation. - Apart from the strong polymorphism workers vary enormously in shape and painting, sculpture and pubescence. Copies of Columbia, Bolivia, Peru and Costa Rica are dark brown and the soldiers have dull occipital (var opaca), while the females are covered with hair sticking out. Little Workers of Trinidad (3-4 mm) are bright yellow and very shiny all over her body (formerly referred to by me as lutea). The shape of the stipes varies (cf Borgm. In 1950, FIG 39, 43-46), also the head of conspecific males (ibid. Fig 47-51). The shape of the Sagitta is relatively constant (Fig. ibid. 35-37).

Synonymy. - The large variability of cephaloles it is not surprising that a number of synonyms exist in the literature. In the old synonyms that are far from clear, I do not discuss (d Emery, 1923).

Borgmeier, T. (1959) Revision der Gattung Atta Fabricius (Hymenoptera, Formicidae). Stud. Entomol., (n.s.)2, 321-390.
Cherrett, J.M. (1986) The biology, pest status and control of leaf-cutting ants. Agric. Zool. Rev., 1, 1-27.
Cherrett, J.M. & Peregrine, D.J. (1976) A review of the status of leaf-cutting ants and their control. Ann. Appl. Biol., 84, 124-128.
Hlldobler, B. & Wilson, E.O. (1990) The ants. Harvard University Press, Cambridge, Mass., xii + 732 pp.
Solomon, S.E. (2007) Biogeography and evolution of widespread leafcutting ants, Atta spp. (Formicidae, Attini). Ph.D. thesis, The University of Texas at Austin, xi + 95 p.
Taxonomic Treatment (provided by Plazi)
Scientific Name Status Publication Pages ModsID GoogleMaps
Atta cephalotes Forel, A., 1905, Miscellanea myrmicologiques, II (1905)., Annales de la Societe Entomologique de Belgique 49, pp. 155-185: 157, (download) 157 4001
Atta cephalotes Forel, A., 1908, Fourmis de Costa-Rica, récoltées par M. Paul Biolley., Bulletin de la Societe Vaudoise des Sciences Naturelles 44, pp. 35-72: 40, (download) 40 4014
Atta cephalotes Borgmeier, T., 1939, Nova contribuição para o conhecimento das formigas neotropicais (Hym. Formicidae)., Revista de Entomologia, São Paulo 10, pp. 403-428: 423-424, (download) 423-424 6484
Specimen Habitat Summary
Found most commonly in these habitats: 115 times found in montane wet forest, 24 times found in mature wet forest, 29 times found in tropical rainforest, 7 times found in tropical wet forest, 13 times found in 2º lowland rainforest, 12 times found in wet forest, 9 times found in rainforest, 10 times found in lowland rainforest, 11 times found in tropical moist forest, 10 times found in lowland wet forest, ...

Found most commonly in these microhabitats: 55 times ex sifted leaf litter, 51 times at bait, 33 times Sobre Vegetacion, 4 times ground, 15 times beating vegetation, 2 times column on ground, 2 times foraging trail, 6 times beating veg., 5 times Malaise trap, 6 times Hojarasca, 2 times foragers, ...

Collected most commonly using these methods: 54 times Malaise, 51 times Baiting, 9 times hand collecting, 22 times search, 32 times MiniWinkler, 33 times Sweeping, 29 times flight intercept trap, 21 times Beating, 17 times Red de golpeo, 15 times MaxiWinkler, 9 times Foggin, ...

Elevations: collected from 4 - 1800 meters, 430 meters average

Type specimens: syntype of Atta cephalotes integrior: casent0909438, casent0909439; syntype of Atta cephalotes opaca: casent0909440; syntype of Atta cephalotes polita: casent0905008; syntype of Atta lutea: casent0909441

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