An international group of entomologists has described a new genus and species of fungus-farming ant from Brazil.

Fungus-growing ants (tribe Attini) make up a group of more than 240 species. They evolved more than 50 million years ago, growing elaborate fungal gardens as a source of food within nests for their colonies.

These ants are nocturnal and forage for organic debris to grow their fungus gardens, which hang in curtain-like columns from the ceilings of their hidden underground chambers.

The fungi that the Attini ants cultivate are probably not completely dependent upon their ant partners to survive and reproduce; they may be capable of surviving independently. The ants, however, are obligatorily dependent on the fungi for their survival.

While theories about the origin of Attini ants’ relationships with fungi remain a topic of debate, entomologists generally support the hypothesis that ants first began to interact with fungi by sharing overlapping habitats.

The new species of fungus-growing ant from Brazil has been named Cyatta abscondita.

The genus name, Cyatta, is a neologism constructed in part from the Brazilian Tupi language word Cy, meaning ‘sister,’ and the name of the ant genus Atta. The specific name, abscondita, means ‘hidden ant’ and refers to the exceedingly secretive nature of the new species.

Cyatta abscondita is considered to be a ‘living fossil,’ which can reveal ways in which early Attini ants may have lived.

“Through our DNA analysis, we learned that the new species is very closely related to the first ant ancestor that began growing fungal gardens. Given this relationship, we can infer that some of Cyatta abscondita’s unique physical and behavioral characteristics hint at what the first agricultural ants and their predecessors looked and acted like,” said Jeffrey Sosa-Calvo from the University of Maryland, the lead author of a paper describing Cyatta abscondita in the open-access journal PLoS ONE.

Cyatta abscondita was first recognized by Jeffrey Sosa-Calvo and his colleagues as a single misidentified specimen in 2003 in the collections of the Museum of Zoology at the University of Sao Paulo in Brazil.

Based on where the specimens had been collected, the entomologists traced the location of the species to two separate, highly threatened, biomes in Brazil: Caatinga, an underexplored desert-like region populated widely by small thorny vegetation, and Cerrado, a tropical savanna region known among experts as a biodiversity hotspot.

“After discovering such an informative species in Caatinga and Cerrado, we are very excited to return to these regions to learn more about this fascinating group of ants,” said study second author Dr Ted Schultz of Smithsonian’s National Museum of Natural History.

“With the majority of the world’s invertebrates still waiting to be identified, the age of discovery is only just beginning.”

“Brazil is a key steward in understanding our planet’s incredible natural history and biodiversity, and it plays a vital role in making findings like this possible,” Dr Schultz concluded.

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Sosa-Calvo J et al. 2013. Cyatta abscondita: Taxonomy, Evolution, and Natural History of a New Fungus-Farming Ant Genus from Brazil. PLoS ONE 8 (11): e80498; doi: 10.1371/journal.pone.0080498