''Cephalotes atratus'' is a species of

arboreal Arboreal locomotion is the Animal locomotion, locomotion of animals in trees. In habitats in which trees are present, animals have evolved to move in them. Some animals may scale trees only occasionally, but others are exclusively arboreal. Th ...

ant Ants are eusocial insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from vespoid wasp ancestors in the Cretaceous period. More than 13,800 of an estimated total of 22 ...

in the genus ''

Cephalotes ''Cephalotes'' is a genus of tree-dwelling ant species from the Americas, commonly known as turtle ants. All appear to be gliding ants, with the ability to "parachute" and steer their fall so as to land back on the tree trunk rather than fall t ...

'', a genus characterized by its odd shaped head. These ants are known as

gliding ant Gliding ants are arboreal ants of several different genera that are able to control the direction of their descent when falling from a tree. Living in the rainforest canopy like many other gliders, gliding ants use their gliding to return to the ...

s because of their ability to "parachute" by steering their fall if they lose their footing.

Names

It is called kaka-sikikoko in the

Kwaza language Kwaza (also written as Kwazá or Koaiá) is an endangered language, endangered Amazonian language spoken by the Kwaza people of Brazil. Kwaza is an unclassified language. It has grammatical similarities with neighboring Aikanã language, Aikanã ...

Rondônia Rondônia () is one of the 26 states of Brazil, located in the northern subdivision of the country (central-western part). To the west is a short border with the state of Acre, to the north is the state of Amazonas, in the east is Mato Grosso, ...

, Brazil.Manso, Laura Vicuña Pereira. 2013.
Dicionário da língua Kwazá
'. M.A. dissertation.

Guajará-Mirim Guajará-Mirim is a municipality in the Brazilian state of Rondônia. It is located at an altitude of 128 meters. Its population was 46,556 (2020) and its area is 24,856 km².IBGE /ref> Location Guajará-Mirim lies along the Mamoré River, j ...

Federal University of Rondônia The Federal University of Rondônia ( pt, Universidade Federal de Rondônia, UNIR) is located in the state of Rondônia, in Brazil. It is the only public university in Rondônia. Campuses The Federal University of Rondônia has 8 campuses locat ...

Description

''Cephalotes atratus'' is a large, mainly black ant; workers are in length and females . Males are up to 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.

Distribution

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.

Biology

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.

Ecology

''Cephalotes atratus'' is

omnivorous An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nutri ...

and feeds on what it can find. A major part of the diet is the secretions produced by

treehopper Treehoppers (more precisely typical treehoppers to distinguish them from the Aetalionidae) and thorn bugs are members of the family (biology), family Membracidae, a group of insects related to the cicadas and the leafhoppers. About 3,200 species ...

s. Ants on the ground collect insect remains from bird droppings, and it will feed on carrion and garbage as well as attack other insects. It does not seem to eat plant material. The armouring is sufficiently heavy to prevent predation by similar sized attackers. In one instance, a troop of

army ant The name army ant (or legionary ant or ''marabunta'') is applied to over 200 ant species in different lineages. Because of their aggressive predatory foraging groups, known as "raids", a huge number of ants forage simultaneously over a limit ...

s ''

Nomamyrmex esenbeckii ''Nomamyrmex'' is a genus of army ants in the subfamily Dorylinae. Its two species are distributed in the Neotropics: ''Nomamyrmex esenbeckii'' is known from southern United States to northern Argentina, and ''Nomamyrmex hartigii'' is known fro ...

'' was seen attacking a colony, and the ''C. atratus'' workers made a living wall to defend the entrance, aligning their heavily

sclerotised Sclerotin is a component of the cuticle of various Arthropoda, most familiarly insects. It is formed by cross-linking members of particular classes of protein molecules, a biochemical process called sclerotization, a form of tanning in which qui ...

heads to prevent the army ants from getting inside to attack their brood. This ant is the only known definitive

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County People *Jim Host (born 1937), American businessman * Michel Host ...

of the

nematode The nematodes ( or grc-gre, Νηματώδη; la, Nematoda) or roundworms constitute the phylum Nematoda (also called Nemathelminthes), with plant-Parasitism, parasitic nematodes also known as eelworms. They are a diverse animal phylum inhab ...

Myrmeconema neotropicum ''Myrmeconema neotropicum'' is a tetradonematid nematode parasite. It appears to induce fruit mimicry in the tropical ant. Presently the only known host species is ''Cephalotes atratus'', a South American ant with a black abdomen. Upon infectio ...

''. 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.

References

{{Taxonbar, from=Q3664949 atratus Ants described in 1758 Taxa named by Carl Linnaeus