Atta robusta

Atta robusta
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Atta
Species:	A. robusta
Binomial name
Atta robusta Borgmeier, 1939 Specimen Labels

Barros et al. (2015) - Atta robusta, an endemic leafcutter ant of the ‘‘restinga’’ ecosystem (sandy open vegetation along the Brazilian coastline), occurs from northern regions of the state of Espírito Santo to the south of the state of Rio de Janeiro, Brazil. It is even one of the few ants of this genus endemic to the restricted area. The species was included in the list of threatened fauna, mainly because of the intense human occupation of the ecosystem in its region of occurrence, as well as because of the indiscriminate chemical use for control of the leafcutter ants. Furthermore, it is possible that plant cover removal from the restinga directly influences the temperature and humidity control necessary for cultivation of the fungus on which they feed. A. robusta plays a significant role in vegetation regeneration because it interacts with at least 36 plant species from the restinga of Guriri Island, state of Espírito Santo, throughout the year (reviewed in Teixeira et al. 2008). Because it does not exert any kind of economic impact and cannot be considered a pest, most of the studies conducted on this species are recent.

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -18.41666667° to -23.05°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality).

Distribution based on AntMaps

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.

Biology

Explore Fungus Growing  For additional details see Fungus growing ants. A handful of ant species (approx. 275 out of the known 15,000 species) have developed the ability to cultivate fungus within their nests. In most species the fungus is used as the sole food source for the larvae and is an important resource for the adults as well. Additionally, in a limited number of cases, the fungus is used to construct part of the nest structure but is not as a food source. These fungus-feeding species are limited to North and South America, extending from the pine barrens of New Jersey, United States, in the north (Trachymyrmex septentrionalis) to the cold deserts in Argentina in the south (several species of Acromyrmex). Species that use fungi in nest construction are known from Europe and Africa (a few species in the genera Crematogaster, Lasius). The details of fungal cultivation are rich and complex. First, a wide variety of materials are used as substrate for fungus cultivating. The so-called lower genera include species that prefer dead vegetation, seeds, flowers, fruits, insect corpses, and feces, which are collected in the vicinity of their nests. The higher genera include non leaf-cutting species that collect mostly fallen leaflets, fruit, and flowers, as well as the leafcutters that collect fresh leaves from shrubs and trees. Second, while the majority of fungi that are farmed by fungus-feeding ants belong to the family Lepiotaceae, mostly the genera Leucoagaricus and Leucocoprinus, other fungi are also involved. Some species utilise fungi in the family Tricholomataceae while a few others cultivate yeast. The fungi used by the higher genera no longer produce spores. Their fungi produce nutritious and swollen hyphal tips (gongylidia) that grow in bundles called staphylae, to specifically feed the ants. Finally, colony size varies tremendously among these ants. Lower taxa mostly live in inconspicuous nests with 100–1000 individuals and relatively small fungus gardens. Higher taxa, in contrast, live in colonies made of 5–10 million ants that live and work within hundreds of interconnected fungus-bearing chambers in huge subterranean nests. Some colonies are so large, they can be seen from satellite photos, measuring up to 600 m3. Based on these habits, and taking phylogenetic information into consideration, these ants can be divided into six biologically distinct agricultural systems (with a list of genera involved in each category): Nest Construction A limited number of species that use fungi in the construction of their nests. some Crematogaster some Lasius Lower Agriculture Practiced by species in the majority of fungus-feeding genera, including those thought to retain more primitive features, which cultivate a wide range of fungal species in the tribe Leucocoprineae. some Apterostigma Cyatta (1 species) some Cyphomyrmex Kalathomyrmex (1 species) Mycocepurus (6 species) Myrmicocrypta (31 species) Mycetarotes (4 species) Mycetosoritis (2 species) Mycetophylax (21 species) Paramycetophylax (1 species) Xerolitor (1 species) Coral Fungus Agriculture Practiced by species in the Apterostigma pilosum species-group, which cultivate fungi within the Pterulaceae. some Apterostigma Yeast Agriculture Practiced by species within the Cyphomyrmex rimosus species-group, which cultivate a distinct clade of leucocoprineaceous fungi derived from the lower attine fungi. some Cyphomyrmex Generalized Higher Agriculture Practiced by species in several genera of non-leaf-cutting "higher attine" ants, which cultivate a distinct clade of leucocoprineaceous fungi separately derived from the lower attine fungi. Mycetomoellerius (31 species) Paratrachymyrmex (9 species) Sericomyrmex (11 species) Trachymyrmex (9 species) Leaf-Cutter Agriculture A subdivision of higher attine agriculture practiced by species within several ecologically dominant genera, which cultivate a single highly derived species of higher attine fungus. Acromyrmex (56 species) Amoimyrmex (3 species) Atta (20 species) Note that the farming habits of Mycetagroicus (4 species) are unknown. Also, while species of Pseudoatta (2 species) are closely related to the fungus-feeding genus Acromyrmex, they are social parasites, living in the nests of their hosts and are not actively involved in fungus growing. ‎

Genetics

Barros et al. (2015) - The diploid chromosome number observed for A. robusta was 2n = 22, and the karyotypic formula was 18m + 2sm + 2st. Heterochromatic blocks were observed in the centromeric region of most chromosomes, where one pair of metacentric chromosomes is characterized by a GC-rich heterochromatic band in the interstitial region of its long arm. The detection of 18S rDNA using FISH confirmed the presence of single NOR for A. robusta.

Association with Other Organisms

 Explore: Show all Associate data or Search these data. See also a list of all data tables or learn how data is managed.

• This species is a host for the phorid fly Eibesfeldtphora breviloba (a parasitoid) (Quevillon, 2018) (encounter mode primary; direct transmission; transmission outside nest).
• This species is a host for the phorid fly Eibesfeldtphora digitata (a parasitoid) (Quevillon, 2018) (encounter mode primary; direct transmission; transmission outside nest).
• This species is a host for the phorid fly Myrmosicarius exrobusta (a parasitoid) (Quevillon, 2018) (encounter mode primary; direct transmission; transmission outside nest).

Phylogeny

Atta	Atta mexicana Atta insularis Atta texana Atta cephalotes Atta colombica Atta robusta Atta sexdens Atta saltensis Atta vollenweideri Atta bisphaerica Atta goiana Atta laevigata Atta capiguara Atta opaciceps

Based on Barrera, C.A. et al., 2021. Note that only selected species are included.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

• robusta. Atta sexdens subsp. robusta Borgmeier, 1939: 426, fig. 15 (w.q.m.) BRAZIL (Rio de Janeiro).
  • Type-material: syntype workers (number not stated, “numerous”), 3 syntype queens, 2 syntype males.
  • Type-localities: Brazil: Rio de Janeiro, São Bento, 15.x.1935 (M. Torres), Rio de Janeiro, Cordovil, i.1921 (O. Gomes), Rio de Janeiro, 28.ix.1927 (L.A. de Azevido Marques), Rio de Janeiro, Quinta Boa Vista, xi.1922 (Monteiro), Rio de Janeiro, Quissamã (R. Saupp).
  • Type-depositories: DSVB, FRRJ, MZSP.
  • Combination in Atta (Neoatta): Gonçalves, 1942: 348; Borgmeier, 1959b: 370;
  • combination in Atta (Epiatta): Borgmeier, 1950d: 246.
  • Status as species: Gonçalves, 1942: 348; Gonçalves, 1947a: 200; Borgmeier, 1950d: 246; Borgmeier, 1959b: 370 (redescription); Kempf, 1972a: 27; Cherrett & Cherrett, 1989: 53; Bolton, 1995b: 77.
  • Distribution: Brazil.

Description

Karyotype

• See additional details at the Ant Chromosome Database.

 Explore: Show all Karyotype data or Search these data. See also a list of all data tables or learn how data is managed.

• 2n = 22, karyotype = 18M+2SM+2ST (Brazil) (Barros et al., 2015; de Castro et al., 2020).

References

• Albuquerque, E., Prado, L., Andrade-Silva, J., Siqueira, E., Sampaio, K., Alves, D., Brandão, C., Andrade, P., Feitosa, R., Koch, E., Delabie, J., Fernandes, I., Baccaro, F., Souza, J., Almeida, R., Silva, R. 2021. Ants of the State of Pará, Brazil: a historical and comprehensive dataset of a key biodiversity hotspot in the Amazon Basin. Zootaxa 5001, 1–83 (doi:10.11646/zootaxa.5001.1.1).
• Anderson, P.S.L., Rivera, M.D., Suarez, A.V. 2020. “Simple” Biomechanical Model for Ants Reveals How Correlated Evolution among Body Segments Minimizes Variation in Center of Mass as Heads Get Larger. Integrative and Comparative Biology. (doi:10.1093/ICB/ICAA027).
• Barrera, C.A., Sosa-Calvo, J., Schultz, T.R., Rabeling, C., Bacci, M., Jr 2021. Phylogenomic reconstruction reveals new insights into the evolution and biogeography of Atta leaf-cutting ants (Hymenoptera: Formicidae). Systematic Entomology 47: 13-35 (doi:10.1111/syen.12513).
• Barros, L. A. C., H. de Aguiar, G. A. Teixeira, C. D. F. Mariano, M. D. Teixeira, J. H. C. Delabie, and S. D. Pompolo. 2015. Cytogenetic data on the threatened leafcutter ant Atta robusta Borgmeier, 1939 (Formicidae: Myrmicinae: Attini). Comptes Rendus Biologies. 338:660-665. doi:10.1016/j.crvi.2015.07.006
• Borgmeier, T. 1939. Nova contribuiça~o para o conhecimento das formigas neotropicas (Hym. Formicidae). Rev. Entomol. (Rio J.) 10: 403-428. (page 426, fig. 15 worker, queen, male described)
• Borgmeier, T. 1950d. Estudos sôbre Atta (Hym. Formicidae). Mem. Inst. Oswaldo Cruz Rio J. 48: 239-263 (page 246, Combination in Atta (Epiatta))
• Borgmeier, T. 1959b. Revision der Gattung Atta Fabricius (Hymenoptera, Formicidae). Stud. Entomol. (n.s.) 2: 321-390. (page 370, Combination in Atta (Neoatta))
• Cardoso, D. C., Cristiano, M. P. 2021. Karyotype diversity, mode, and tempo of the chromosomal evolution of Attina (Formicidae: Myrmicinae: Attini): Is there an upper limit to chromosome number? Insects 1212, 1084 (doi:10.3390/insects12121084).
• de Castro, C.P.M., Cardoso, D.C., Micolino, R., Cristiano, M.P. 2020. Comparative FISH-mapping of TTAGG telomeric sequences to the chromosomes of leafcutter ants (Formicidae, Myrmicinae): is the insect canonical sequence conserved? Comparative Cytogenetics 14(3): 369–385 (doi:10.3897/CompCytogen.v14i3.52726).
• Farias, A.P., Camargo, R.da S., Caldato, N., Forti, L.C. 2020. Nest architecture development of grass-cutting ants, Atta capiguara (Hymenoptera: Formicidae). Revista Brasileira de Entomologia 64, e20200034 (doi:10.1590/1806-9665-rbent-2020-0034).
• Forti, L.C., Rando, J.S., Camargo, R.D.S., Moreira, A.A., Castellani, M.A., Leite, S.A., Sousa, K.K.A., Caldato, N. 2020. Occurrence of Leaf-Cutting and Grass-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae) in Geographic Regions of Brazil. Sociobiology 67, 514-525 (doi:10.13102/sociobiology.v67i4.5741).
• Fowler, H. G. 1995. The population status of the endangered Brazilian endemic leaf-cutting ant Atta robusta (Hymenoptera: Formicidae). Biol. Conserv. 74: 147–150.
• Fowler, H. G., Delabie, J. H. C., and Schlindwein, M. N. 1996. The endemic Brazilian leaf-cutting ants, Atta silvai and Atta robusta (Hymenoptera: Formicidae): Population status. Rev. Brasileira Entomol. 40: 111–112.
• Gonçalves, C. R. 1942. Contribuiça~o para o conhecimento do gênero Atta Fabr., das formigas saúvas. Bol. Soc. Bras. Agron. 5: 333-358 (page 348, Combination in Atta (Neoatta), Raised to species)
• Moura, M.N., Cardoso, D.C., Cristiano, M.P. 2020. The tight genome size of ants: diversity and evolution under ancestral state reconstruction and base composition. Zoological Journal of the Linnean Society, zlaa135 (doi:10.1093/zoolinnean/zlaa135).
• Silva, P.S., Koch, E.B. de A., Arnhold, A., Delabie, J.H.C. 2022. Review of distribution modeling in ant (Hymenoptera: Formicidae) biogeographic studies. Sociobiology 69(4), e7775 (doi:10.13102/sociobiology.v69i4.7775).

References based on Global Ant Biodiversity Informatics

• Borgmeier T. 1950. Atta-Studien (Hym. Formicidae). Memórias do Instituto Oswaldo Cruz. Rio de Janeiro 48: 265-292.
• Borgmeier T. 1950. Estudos sôbre Atta (Hym. Formicidae). Memórias do Instituto Oswaldo Cruz. Rio de Janeiro 48: 239-263.
• Fowler H. G., J. H. C. Delabie, and M. N. Schlindwein. 1996. The endemic brazilian leaf-cutting ants, Atta silvai and Atta robusta (Hymenoptera, Formicidae): populations status. Revta bras. Ent. 40(1): 111-112.
• Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).