Acromyrmex fracticornis

Acromyrmex fracticornis
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Acromyrmex
Species:	A. fracticornis
Binomial name
Acromyrmex fracticornis (Forel, 1909) Specimen labels
Synonyms
Acromyrmex fracticornis jorgenseni Forel, 1913

This species was found to be a pest in pastures in Paraguay, feeding on the grasses Cenchrus ciliaris, Chloris gayana, Cynodon nlemfuensis, Digitaria eriantha, Megathyrsus maximus, Paspalum notatum, Urochloa brizantha, Urochloa decumbens, Urochloa mosambicensis and Urochloa ruziziensis (Sarubbi & Ramirez, 2020).

Distribution

Latitudinal Distribution Pattern

Latitudinal Range: -16.256667° to -34.604°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Brazil, Paraguay (type locality), Uruguay.

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. ‎

Nesting Habits

Acromyrmex fracticornis constructs conspicuous nest turrets made of interlaced plant fragments. Corsarinsky et al. (2020) asked whether turrets are built by merely piling up nearby materials around the nest entrance, or whether ants incorporate different materials as the turret develops. Their experiments revealed that consolidation of the turret occurred both over time and from its base upwards. Different building behaviors are involved, namely (1) intermeshing grass fragments and twigs around the nest opening, (2) cementing the resulting mesh with soil pellets, and (3) lining the inner gallery wall. Nest turrets do not simply arise by the arbitrary deposition of nearby materials, since workers both selectively incorporate large materials at the beginning, and respond to the developing structure by reinforcing the intermeshed plant fragments over time.

• 

  Examples of turrets of unknown age from field nests of Acromyrmex fracticornis located in Formosa, Argentina. (a) Turret built with grass fragments, internally lined with soil pellets (not visible). (b) Lateral view of a turret built with grass fragments located on top of a slightly elevated mound composed of excavated soil pellets. (c) Example of a turret with two adjacent openings that merged and led to a single nest entrance at the soil level (not visible). (d) Example of a turret with three openings (yellow arrows). Excavated soil pellets are located in between the grass fragments. Photo credits: (a,b): F. Roces; (c,d): D. Römer. (Corsarinsky et al., 2020, Fig. 1).

Nomenclature

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

• fracticornis. Atta (Moellerius) fracticornis Forel, 1909a: 257 (w.) PARAGUAY.
  • Type-material: syntype workers (number not stated).
  • Type-locality: Paraguay: San Bernardino (K.A.G. Fiebrig).
  • Type-depositories: MHNG.
  • Fowler, 1988: 286 (m.).
  • Combination in Acromyrmex (Moellerius): Forel, 1913l: 236.
  • Subspecies of landolti: Gonçalves, 1961: 126; Kempf, 1972a: 16.
  • Status as species: Emery, 1924d: 351; Santschi, 1925a: 388 (in key); Kusnezov, 1953b: 338; Kusnezov, 1956: 34 (in key); Fowler, 1988: 286; Brandão, 1991: 323; Bolton, 1995b: 55; Wild, 2007b: 30.
  • Senior synonym of jorgenseni: Gonçalves, 1961: 126; Kempf, 1972a: 16; Fowler, 1988: 286; Brandão, 1991: 323; Bolton, 1995b: 55.
  • Distribution: Argentina, Brazil, Paraguay.
• jorgenseni. Acromyrmex (Moellerius) fracticornis var. jorgenseni Forel, 1913l: 236 (w.q.) ARGENTINA (Mendoza).
  • Type-material: syntype workers, syntype queens (numbers not stated).
  • Type-locality: Argentina: Mendoza (P. Jörgensen).
  • Type-depository: MHNG.
  • [Misspelled as joergenseni by Bruch, 1928: 346, and others.]
  • Bruch, 1916: 325 (m.).
  • Subspecies of fracticornis: Bruch, 1915: 529; Bruch, 1916: 325; Gallardo, 1916d: 335; Santschi, 1916e: 389; Emery, 1924d: 351; Santschi, 1925a: 388 (in key); Bruch, 1928: 346; Santschi, 1929d: 304.
  • Junior synonym of fracticornis: Gonçalves, 1961: 126; Kempf, 1972a: 16; Fowler, 1988: 286; Brandão, 1991: 323; Bolton, 1995b: 55.

References

• Cantone S. 2017. Winged Ants, The Male, Dichotomous key to genera of winged male ants in the World, Behavioral ecology of mating flight (self-published).
• Cosarinsky, M.I., Römer, D., Roces, F. 2020. Nest turrets of Acromyrmex grass-cutting ants: Micromorphology reveals building techniques and construction dynamics. Insects 11, 140 (doi:10.3390/insects11020140).
• Culebra Mason, S., Catalano, P., Sgarbi, C., Verzero, F., Blondel, D. Ricci, M., Antonini, A. 2009. Utilización de trampas Pitfall con distintos atrayentes alimentarios para el monitoreo de hormigas en sistemas pastoriles. Boletin de Sanidad Vegetal Plagas 35: 187-192.
• Forel, A. 1909a. Ameisen aus Guatemala usw., Paraguay und Argentinien (Hym.). Dtsch. Entomol. Z. 1909: 239-269 (page 257, worker described)
• Forel, A. 1913m. Fourmis d'Argentine, du Brésil, du Guatémala & de Cuba reçues de M. M. Bruch, Prof. v. Ihering, Mlle Baez, M. Peper et M. Rovereto. Bull. Soc. Vaudoise Sci. Nat. 49: 203-250 (page 236, Combination in Acromyrmex (Moellerius))
• Fowler, H. G. 1988b. Taxa of the neotropical grass-cutting ants, Acromyrmex (Hymenoptera: Formicidae: Attini). Científica (Jaboticabal) 16: 281-295 (page 286, male described, Revived status as species)
• Gonçalves, C. R. 1961. O genero Acromyrmex no Brasil (Hym. Formicidae). Stud. Entomol. 4: 113-180 (page 126, Subspecies of landolti, and senior synonym of jorgenseni)
• Kempf, W. W. 1972b. Catálogo abreviado das formigas da regia~o Neotropical. Stud. Entomol. 15: 3-344 (page 16, Subspecies of landolti, and senior synonym of jorgenseni)
• Sarubbi, H.J., Ramirez, M.B. 2020. Pest insects in natural and sown pastures of Paraguay. Tropical Grasslands-Forrajes Tropicales 8(2) 158–161 (doi:10.17138TGFT(8)158-161).

References based on Global Ant Biodiversity Informatics

• Bonetto A. A. 1959. Las hormigas "cortadoras" de la Provincia de Santa Fé (generos: Atta y Acromyrmex). Santa Fé, Argentina: Ministerio de Agricultura y Ganadería (Dirección General de Recurzos Naturales), 79 pp.
• Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
• Bruch C. 1916. Contribución al estudio de las hormigas de la provincia de San Luis. Revista del Museo de La Plata 23: 291-357.
• Bruch C. 1928. Estudios mirmecológicos. Anales del Museo Nacional de Historia Natural de Buenos Aires 34: 341-360.
• Cuezzo, F. 1998. Formicidae. Chapter 42 in Morrone J.J., and S. Coscaron (dirs) Biodiversidad de artropodos argentinos: una perspectiva biotaxonomica Ediciones Sur, La Plata. Pages 452-462.
• Culebra Mason S., C. Sgarbi, J. Chila Covachina, J. M. Pena, N. Dubrovsky Berensztein, C. Margaria, and M. Ricci. 2017. Acromyrmex Mayr (Hymenoptera: Formicidae: Myrmicinae): species distribution patterns in the province of Buenos Aires, Argentina. Rev. Mus. Argentino Cienc. Nat. 19(2) 185-199.
• Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
• Forel A. 1913. Fourmis d'Argentine, du Brésil, du Guatémala & de Cuba reçues de M. M. Bruch, Prof. v. Ihering, Mlle Baez, M. Peper et M. Rovereto. Bulletin de la Société Vaudoise des Sciences Naturelles. 49: 203-250.
• Fowler H. G. 1985. Leaf-cutting ants of the genera Atta and Acromyrmex of Paraguay (Hymenoptera, Formicidae) Dtsch. Ent. Z., N. F. 32(1-3): 19-34.
• Fowler H. G. 1988. Taxa of the neotropical grass-cutting ants, Acromyrmex (Hymenoptera: Formicidae: Attini). Científica (Jaboticabal) 16: 281-295.
• Gallardo A. 1916. Notes systématiques et éthologiques sur les fourmis attines de la République Argentine. Anales del Museo Nacional de Historia Natural de Buenos Aires 28: 317-344.
• Gonçalves C. R. 1961. O genero Acromyrmex no Brasil (Hym. Formicidae). Stud. Entomol. 4: 113-180.
• Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
• Kusnezov N. 1956. Claves para la identificación de las hormigas de la fauna argentina. Idia 104-105: 1-56.
• Kusnezov N. 1978. Hormigas argentinas: clave para su identificación. Miscelánea. Instituto Miguel Lillo 61:1-147 + 28 pl.
• Murua A. F., F. Cuezzo, and J. C. Acosta. 1999. La fauna de hormigas del Gran Bajo Oriental del departamento Valle Fertíl (San Juan, Argentina). Revista de la Sociedad Entomológica Argentina 58(3/4): 135-138.
• Pignalberi C. T. 1961. Contribución al conocimiento de los formícidos de la provincia de Santa Fé. Pp. 165-173 in: Comisión Investigación Científica; Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina) 1961. Actas y trabajos del primer Congreso Sudamericano de Zoología (La Plata, 12-24 octubre 1959). Tomo III. Buenos Aires: Librart, 276 pp.
• Santschi F. 1925. Fourmis des provinces argentines de Santa Fe, Catamarca, Santa Cruz, Córdoba et Los Andes. Comunicaciones del Museo Nacional de Historia Natural "Bernardino Rivadavia" 2: 149-168.
• Santschi F. 1925. Revision du genre Acromyrmex Mayr. Revue Suisse de Zoologie 31: 355-398.
• Silva F. H. O., J. H. C. Delabie, G. B. dos Santos, E. Meurer, and M. I. Marques. 2013. Mini-Winkler Extractor and Pitfall Trap as Complementary Methods to Sample Formicidae. Neotrop Entomol 42: 351–358.
• Ulyssea M.A., C. E. Cereto, F. B. Rosumek, R. R. Silva, and B. C. Lopes. 2011. Updated list of ant species (Hymenoptera, Formicidae) recorded in Santa Catarina State, southern Brazil, with a discussion of research advances and priorities. Revista Brasileira de Entomologia 55(4): 603-–611.
• Vittar, F. 2008. Hormigas (Hymenoptera: Formicidae) de la Mesopotamia Argentina. INSUGEO Miscelania 17(2):447-466
• Vittar, F., and F. Cuezzo. "Hormigas (Hymenoptera: Formicidae) de la provincia de Santa Fe, Argentina." Revista de la Sociedad Entomológica Argentina (versión On-line ISSN 1851-7471) 67, no. 1-2 (2008).
• Wild, A. L. "A catalogue of the ants of Paraguay (Hymenoptera: Formicidae)." Zootaxa 1622 (2007): 1-55.