Amoimyrmex striatus

Amoimyrmex striatus
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Hymenoptera
Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Attini
Genus:	Amoimyrmex
Species:	A. striatus
Binomial name
Amoimyrmex striatus (Roger, 1863) Specimen labels
Synonyms
Acromyrmex striatus laeviventris Santschi, 1925

Locally abundant in some areas within its range, colonies of Amoimyrmex striatus live in relatively small subterranean nests in areas of low vegetation cover.

At a Glance

• Polygynous  • Diploid male

Identification

Cristiano, Cardoso and Sandoval (2020) - Distinguished from congeners by the combination of: body yellowish‐brown to reddish‐brown, with dark brown gaster; pronotum with a pair of minute median pronotal projections as tubercles, best seen in frontal view; shiny integument covered by parallel irregular striae and scarce yellowish non‐decumbent setae, varying in length; posterior cephalic corner acute; anterior portion of the first gastral tergite almost smooth, with few short irregular striae, discernible in medium magnification (~50×)

A. striatus has distinctive irregular parallel striation, a shiny integument (more than A. silvestrii), comparatively less pilosity in the metasoma, and shorter irregular striae in the first gastral tergite, restricted to the insertion of the postpetiole (two‐thirds of the tergite in A. silvestrii).

Keys including this Species

• Key to Amoimyrmex workers

Distribution

Cristiano, Cardoso and Sandoval (2020) - The species has been found in Argentina, Brazil and Uruguay, three bordering countries of South America (Kusnezov 1963; Delabie et al. 2011; Cristiano et al. 2016; Simões‐Gomes et al. 2017). We consider that the Paraná River Basin delimits the species distribution and influenced the diversification of the species of Amoimyrmex, as well as providing the dispersal route during past geomorphological and climatic changes. Its known distribution in Brazil is restricted to the southern region, in the states of Santa Catarina and Rio Grande do Sul, on the coastal plains, reaching as far north as Florianópolis Island (Cristiano et al. 2016; Simões‐Gomes et al. 2017). In Rio Grande do Sul, the species occurs further inland, with high abundance across the Central Depression of the State (Loeck et al. 2003). This geomorphological region is the likely dispersal route of A. striatus to the southern Brazilian coast (Cristiano et al. 2016). Cristiano et al. (2016) also suggested that A. striatus populations are geographically and genetically structured and estimated the coastal Brazilian populations to be younger than the inland populations. The distribution of the species in Argentina and Uruguay is still not well known, but its distribution in the former seems to be restricted to the provinces of Misiones, Corrientes and Entre Rios, which circumscribe the Paraná River Basin.

Latitudinal Distribution Pattern

Latitudinal Range: -22.809943° to -40.7°.

North Temperate	North Subtropical	Tropical	South Subtropical	South Temperate

• Source: AntMaps

Distribution based on Regional Taxon Lists

Neotropical Region: Argentina, Bolivia, Brazil, Paraguay, Uruguay (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

Expand 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 (33 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 (51 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. ‎

Jofre et al. (2018) - Amoimyrmex striatus is one of the most common leaf-cutting ant species in Argentina (Farji-Brener & Ruggiero, 1994). This species constructs relative small subterranean nests in areas of low vegetation cover. Workers forage at close distances from the nest without a defined network trail system (Boneto, 1959; Diehl-Fleig, 1995). Amoimyrmex striatus consumes a high percentage of plant species available in the environment (Armani & Quirán, 2007; Nobua-Behrmann, 2014), and their degree of selectivity or opportunism depends on the availability of resources within the proximity of their colonies (Farji-Brener & Protomastro, 1992; Pilati et al., 1997; Franzel & Farji-Brener, 2000; Armani & Quirán, 2007; Nobua-Behrmann, 2014).

Nesting Biology

Cristiano, Cardoso and Sandoval (2020) - Amoimyrmex striatus nests in open and well‐drained soils and prefers soils poor in organic matter (Diehl‐Fleig & Rocha 1998). The nests can be easily recognized by the bare soil around the nest entrances, which consist of entrance holes without craters or mounds (Diehl‐Fleig 1995). It is suspected that the workers clean the soil surface above the subterranean chambers by removing all vegetation, as if it had been weeded and swept. The nest architecture, as presented as a figure by Weber, consists of several small and interconnected chambers. The nest openings are 5–7 mm wide and 49–150 mm deep, with the first chamber beginning lateral to the tunnel (Della‐ Lucia & Moreira 1993). The fungus garden is suspended from the roof of the chamber, although in our field expeditions, we found that the fungus garden may also be sessile on the chamber floor.

Foraging/Diet

Cristiano, Cardoso and Sandoval (2020) - Amoimyrmex striatus is described as a leaf‐cutting ant specialising on monocots (Gonçalves 1961). However, when studying plant resources used by A. striatus in Florianópolis, Brazil, Lopes (2005) observed that the species used different resources seasonally and could cut both monocot and dicot leaves. Indeed, the author also suggested that A. striatus could be an opportunistic scavenger, using dead exhausted materials for fungus cultures. This behaviour is similar to that observed for other fungus‐farming ants, such as Trachymyrmex, whose workers can facultatively cut fresh material to cultivate their fungus but rely mainly on insect frass and organic debris (Weber 1972). This information improves our understanding of the evolutionary transitions to higher attine agriculture because relying on freshly cut vegetation is congruent with the phylogenetic position of Amoimyrmex.

Nobua-Behrmann et al. (2017) studied temporal and thermal aspects of Amoimyrmex striatus foraging behavior in the Monte Desert in Argentina where this species co-occurs with Acromyrmex lobicornis. Amoimyrmex striatus colonies were active during spring and summer, with no signs of foraging activity during winter. Foraging intensity was highest during spring and summer, with up to 90 ants (foragers returning to the nest) / 5 minutes. During spring and summer, foraging activity was exclusively diurnal with 4 - 6 hours of foraging during the morning and 4 hours in the afternoon, avoiding the hotter midday. This changed to a single period of low activity concentrated during the hottest part of the day in autumn. During the hottest months, the overall daily foraging pattern appears to be complementary to its similar co-occurring congener: Am. striatus daily foraging activity begins in the mornings when Ac. lobicornis colonies are ceasing their foraging activity cycle. Furthermore, the ending of Am. striatus colonies foraging activity in the evenings also coincides with the beginning of Ac. lobicornis foraging. During autumn, colonies showed very scarce activity (< 15 ants / 5 minutes in any single colony). Daily and seasonal variations in nest maintenance activity were broadly similar to foraging activity patterns, though spanning larger time ranges than their foraging activity (starting earlier and finishing later).

The ants foraged within a particular temperature range that was relatively constant throughout the year and differed from its congener: Am. striatus colonies foraged at higher temperatures than Ac. lobicornis in all seasons (26 - 45 °C vs. 16 - 35 °C, respectively).

Jofre et al. (2018) - Foraging behavior was studied in a natural reserve of San Luis, Argentina. The chaco vegetation found within the reserve had in the past been affected by overgrazing, fire, and logging. In addition to quantifying the plants selected by foragers, it was found that small nests of Am. striatus harvested a greater percent of the plant species available in their foraging area and showed a higher level of selectivity than larger nests.

Reproduction

Cristiano, Cardoso and Sandoval (2020) - Colonies of the species may be founded by a single fertilized female (haplometrosis) or by the association of more than one fertilised female (pleometrosis), depending on density and physical distances between founders (Diehl‐Fleig & de Araújo 1996). The production of sexuals is suggested to occur from the end of October to mid‐January and to be male biased (Diehl‐Fleig 1993). Nuptial flights seem to occur in small and patchy daily swarms (Diehl‐ Fleig 1993).

Ecology

Barrera et al. (2015) studied the diversity of leaf cutting ants along a forest-edge-agriculture habitat gradient. Their study site, in Chaco Serrano of Central Argentina, had forest remnants of various sizes within an agriculture area with wheat, soy and maize. A. striatus was moderately abundant (17% of the 162 colonies sampled). Along the forest edge it was similar in abundance to Acromyrmex lundii, with Acromyrmex crassispinus also present but occurring at a slightly lower abundance. A few colonies of Acromyrmex heyeri and Amoimyrmex silvestrii were also found along the forest edge. Ten nets were found within 5m of the forest edge but none were sampled 25m from the forest edge in the croplands. A. striatus was not found in the forest interior but was the most common species in the cropland matrix close to the forest edge. This suggests this species may do well in disturbed areas. In some regions A. striatus is known as a pest species (Diehl-Fleig, 1993).

Life History Traits

• Queen number: polygynous (Cournault & Aron, 2009)

Castes

Worker

Images from AntWeb

Worker. Specimen code casent0104327. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by CAS, San Francisco, CA, USA.

Worker. Specimen code casent0173803. Photographer April Nobile, uploaded by California Academy of Sciences.	Owned by ALWC, Alex L. Wild Collection.

Cristiano, Cardoso and Sandoval 2020, Figure 19.

Cristiano, Cardoso and Sandoval 2020, Figure 20.

Reproductive Castes

Queen. Cristiano, Cardoso and Sandoval 2020, Figure 21.

Male. Cristiano, Cardoso and Sandoval 2020, Figure 22.

Diploid males are known to occur in this species (found in 0.7% of 140 examined nests) (Araújo & Cavalli-Molina, 2001; Cournault & Aron, 2009).

Nomenclature

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

• striatus. Atta striata Roger, 1863a: 202 (q.m.) URUGUAY.
  • Type-material: syntype queens, syntype males (numbers not stated, “a number”).
  • Type-locality: Uruguay: Montevideo (no collector’s name).
  • Type-depository: MNHN.
  • [Note: Roger, 1863a: 203, mentions two workers from Argentina: La Plata which “probably belong to this species”. Because of the provisional nature of this statement, and the differences in caste and locality, these workers are excluded from the type-series.]
  • Combination in Atta (Oecodoma): Mayr, 1863: 458;
  • combination in Atta (Acromyrmex): Forel, 1885a: 361; Emery, 1888c: 357;
  • combination in Atta (Moellerius): Emery, 1905c: 42;
  • combination in Acromyrmex: Bruch, 1914: 217;
  • combination in Acromyrmex (Moellerius): Gallardo, 1916d: 338; Emery, 1924d: 351;
  • combination in Amoimyrmex: Cristiano, et al. 2020: 667.
  • Status as species: Roger, 1863b: 35; Mayr, 1863: 458; Forel, 1885a: 361 (in key); Emery, 1888c: 357; Emery, 1888e: 690; Dalla Torre, 1893: 154; von Jhering, 1894: 388; Forel, 1895b: 139; Emery, 1905c: 42; Emery, 1906c: 166; Forel, 1912e: 181; Bruch, 1914: 217; Gallardo, 1916d: 338; Santschi, 1916e: 389; Emery, 1924d: 351; Santschi, 1925a: 389 (in key); Borgmeier, 1927c: 136; Kusnezov, 1953b: 338; Kusnezov, 1956: 34 (in key); Gonçalves, 1961: 129; Kempf, 1972a: 16; Zolessi & Abenante, 1977: 78; Zolessi, et al. 1988: 5; Fowler, 1988: 290; Cherrett & Cherrett, 1989: 52; Brandão, 1991: 323; Bolton, 1995b: 57; Wild, 2007b: 30; Cristiano, et al. 2020: 667 (redescription).
  • Senior synonym of laeviventris: Fowler, 1988: 290; Brandão, 1991: 323; Bolton, 1995b: 57.
  • Distribution: Argentina, Brazil, Uruguay.
• laeviventris. Acromyrmex (Moellerius) striatus var. laeviventris Santschi, 1925a: 388.
  • [First available use of Acromyrmex (Moellerius) striatus st. silvestrii var. laeviventris Santschi, 1920d: 380 (w.) ARGENTINA (Jujuy, Santa Fe); unavailable (infrasubspecific) name.]
  • Type-material: syntype workers (number not stated).
  • Type-localities: Argentina: Jujuy, La Quiaca (Naiva) (invalid restriction of type-locality by Kempf, 1972a: 16; no lectotype designated), Argentina: Santa Fé (M. Birabén).
  • Type-depository: NHMB.
  • Subspecies of striatus: Kempf, 1972a: 16.
  • Junior synonym of striatus: Fowler, 1988: 290; Brandão, 1991: 323; Bolton, 1995b: 55.

Type Material

Cristiano, Cardoso and Sandoval (2020) - We could not locate the type specimen Roger used to describe A. striatus. Roger questioned if the reproductive caste and worker specimens were the same species (Roger 1863). The types were also from different countries – the queen and male from Uruguay and the workers from Argentina. Thus the taxonomic history of the species is centered around a series of uncertain identification, as suggested by Klingenberg and Brandão (2009) in the cases of Mycetophylax, Cyphomyrmex and Myrmicocrypta.

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.

• n = 11, 2n = 22, karyotype = 20M + 2SM (Argentina, Brazil) (Cristiano et al., 2013; de Castro et al., 2020; Micolino et al., 2021).

Amoimyrmex striatus shares the characteristics of both Acromyrmex and Atta, as it presents peculiarities such as its karyotype formula 2K = 20M + 2SM, indicating that A. striatus may be better classified as a genus distinct from its sibling leafcutter ants (Cristiano et al., 2013; de Castro et al., 2020). Cristiano, Cardoso & Sandoval (2020) transferred this species to the newly established genus Amoimyrmex.

Worker

Cristiano, Cardoso and Sandoval (2020) - Range (specimen used for redescription): TL 3.36–8.82 (7.07), HL 0.72–1.94 (1.64), HW 0.70–2.30 (1.83), ML 0.30–0.88 (0.55), SL 0.54–1.82 (1.52), EL 0.10– 0.35 (0.29), WL 0.90–2.80 (2.14), PL 0.24–0.74 (0.55), PW 0.22–0.63 (0.43), PPL 0.24–0.65 (0.48), PPW 0.34–1.12 (0.81), GL 0.96–2.12 (1.71), CI 92.86–141.54 (111.59), MI 29.33–50.00 (33.33), OI 12.96–19.23 (15.58), SI 73.02– 110.34 (92.75) [N = 156].

Head. In full‐face view, posterior cephalic margin medially emarginate. Posterior cephalic corner acute, with a small spine or tubercle directed upwards, faintly visible on dorsum of head in lateral view, and a small tubercle laterad. Integument covered by parallel irregular striae and scarce yellowish non‐decumbent setae, varying in length. Frontal carina, that may be confused with striae, extending to vertex and almost reaching posterior cephalic corner. Mandible with 8–11 teeth (some can be considered denticles, varying in size and position), dorsally glossy with superficial striae and covered by sparse light‐coloured hairs, with larger and thicker ones at masticatory margin. Eye convex, 19–24 ommatidia across largest diameter. Frontal lobe partially covering antennal insertions, with a hook shape. Antennal scrobe absent. Antennal scape slightly surpassing posterior cephalic margin, less than 1/3 of its length (SI = 73.02– 110.34). Colour yellowish‐brown to reddish‐brown. Mesosoma. Pronotum armed with two large lateral pronotal spines and minute median pronotal projections as tubercles, best seen in frontal view. Mesonotum with two lateral mesonotal spines and two posterior mesonotal spines, with similar size and approximately half of the size of the lateral pronotal spines. Propodeum bearing two large spines, moderately larger than lateral pronotal spines. Integument covered by parallel irregular striae and scarce non‐decumbent pilosity, reaching up the spines. Legs with conspicuous reticulation, in some cases with coxa and femur darker than the rest of body. Metasoma. Petiolar node with four spine‐like projections directed up and backwards and two lateral longitudinal carinae. Postpetiole node with two small teeth on lateral margins, located in medial portion, projecting laterally and slightly backwards, best seen in dorsal view, and two lateral longitudinal carinae. Dorso‐posterior region of node with two small tubercles. Integument of petiole and postpetiole covered by parallel striae and non‐decumbent pilosity. Gaster darker than rest of body with smooth and shiny integument and scarce yellowish non‐decumbent setae of two sizes, being the longest ones twice the size of the small ones. Anterior portion of first gastral tergite almost smooth, with few short irregular striae, discernible in medium magnification (~50×), close to base of gaster.

Queen

Cristiano, Cardoso and Sandoval (2020) - TL 9.50–10.70, HL 1.75–1.95, HW 2.25–2.30, ML 0.80–0.90, SL 1.50–1.65, EL 0.35–0.40, WL 2.65–3.25, PL 0.73–0.75, PW 0.65–0.70, PPL 0.75–0.78, PPW 1.05–1.30, GL 2.70–3.10, CI 115.38–111.43, MI 43.24– 46.15, OI 15.56–17.39, SI 81.08–88.57 [N = 9].

Head. In full‐face view, posterior cephalic margin medially emarginate but less accentuated than worker. Posterior cephalic corner angular, with a small spine directed upwards and a small tubercle laterad. Integument covered by parallel irregular striae but denser than in worker. Frontal carina present (may be confused with striae), shorter than in worker. Eye larger and less convex than in worker. Number of ommatidia across largest eye diameter 28–30. Mandibles with 9 teeth (two can be considered denticles) and apical tooth larger and more prominent than in worker. Mesosoma. Integument with well‐defined and longitudinal and parallel striae and sparse non‐decumbent pilosity but with denser striae than in worker. Scutellum strongly convex in lateral view, narrowing posteriorly with a trapezoidal outline in dorsal view, bearing two denticles in the posterior margin. Propodeum with a pair of protruding long spines, directed upwards, in lateral view. Metasoma. Petiole with a well‐developed subpetiolar process armed with a sharp spine. Integument of postpetiole covered by parallel transversalstriae. First gastral tergite with two yellowish spots located anterolaterally in dorsal view. Dense semicircularstriae present on the first gastral tergite, mainly at the base. Dense pilosity present on gastral tergites two to four; tergite one with sparse setae as in workers. Parallel striae on subsequent tergites.

Male

Cristiano, Cardoso and Sandoval (2020) - TL 8.22–8.36, HL 1.11–1.13, HW 1.25–1.28, ML 0.71–0.72, SL 1.25–1.26, EL 0.32–0.34, WL 2.68–2.70, PL 0.49–0.51, PW 0.51–0.52, PPL 0.64–0.67, PPW 0.78–0.79, GL 2.59–2.63, CI 112.61–113.27, MI 63.72– 63.96, OI 28.82–30.09, SI 111.50–112.61 [N = 3].

Head. In full‐face view subquadrate, posterior cephalic margin straight, without emargination. Posterior cephalic corner rounded with a small spine directed upwards. Integument opaque, reticulated and covered by irregular striae, as in worker and queen. Eye bigger and more convex than worker and queen. Number of ommatidia across largest eye diameter 34. Mesosoma. Scutellum convex, less than queen in lateral view, narrowing posteriorly with a trapezoidal outline in dorsal view, bearing two tuberculiform denticles in the posterior margin. Propodeum with a pair of protruding long spines, directed backwards, in lateral view. Integument with well‐defined longitudinal and parallel striae and scarce non‐decumbent pilosity. Metasoma. Petiole with short peduncle, subpetiolar process smaller than queen, similar with worker and less developed than in Amoimyrmex silvestrii. Postpetiole in dorsal view broader than long, with two small teeth on the lateral margins, located in medial portion, projecting laterally and slightly backwards. Postpetiolar process more developed than in queen and worker, and sharper than in A. silvestrii. Integument of petiole and postpetiole with scarce striae. Gaster with smooth and shiny integument, and non‐decumbent pilosity, less dense and shorter than in queen and its congener Amoimyrmex silvestrii.

References

• Araújo, D.E., Cavalli-Molina, S. 2001. Genetic variability and social structure of colonies in Acromyrmex heyeri and A. striatus (Hymenoptera: Formicidae). Braz J Biol 61:667–678.
• Barrera, C. A., L. M. Buffa, and G. Valladares. 2015. Do leaf-cutting ants benefit from forest fragmentation? Insights from community and species-specific responses in a fragmented dry forest. Insect Conservation and Diversity. 8:456-463. doi:10.1111/icad.12125
• Barros, L.A.C., Aguiar, H.J.A.C., Teixeira, G.C., Souza, D.J., Delabie, J.H.C., Mariano, C.S.F. 2021. Cytogenetic studies on the social parasite Acromyrmex ameliae (Formicidae: Myrmicinae: Attini) and its hosts reveal chromosome fusion in Acromyrmex. Zoologischer Anzeiger 293, 273–281 (doi:10.1016/j.jcz.2021.06.012).
• Brown, M.J.F., Bonhoeffer, S. 2003. On the evolution of claustral colony founding in ants. Evolutionary Ecology Research 5: 305–313.
• Bruch, C. 1914. Catálogo sistemático de los formícidos argentinos. Rev. Mus. La Plata 19: 211-234 (page 217, Combination in Acromyrmex)
• 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).
• Cardoso, D.C. & Fernandes-Salomão, T.M. 2013. Cytogenetic and molecular analyses reveal a divergence between Acromyrmex striatus (Roger, 1863) and other congeneric species: taxonomic implications. PLoS ONE 8(3):e59784 (doi:10.1371/journal.pone.0059784).
• Cardoso, D.C., Schoereder, J.H. 2014. Biotic and abiotic factors shaping ant (Hymenoptera: Formicidae) assemblages in Brazilian coastal sand dunes: The case of restinga in Santa Catarina. Florida Entomologist 97, 1443–1450. (doi:10.1653/024.097.0419).
• Cournault, L., Aron, S. 2009. Diploid males, diploid sperm production, and triploid females in the ant Tapinoma erraticum. Naturwissenschaften 96: 1393–1400 (doi:10.1007/s00114-009-0590-1).
• Cristiano, M. P.; Cardoso, D. C.; Fernandes-Salomão, T. M. 2013. Cytogenetic and molecular analyses reveal a divergence between Acromyrmex striatus (Roger, 1863) and other congeneric species: taxonomic implications. PLoS ONE (doi:10.1371/journal.pone.0059784) 8(3):e59784| PDF
• Cristiano, M.P., Cardoso, C.D., Fernandes-Salomão, T.M., Heinze, J. 2016. Integrating paleodistribution models and phylogeography in the grass-cutting ant Acromyrmex striatus (Hymenoptera: Formicidae) in southern lowlands of South America. PLoS One, 11(1), e0146734 (doi:10.1371/journal.pone.0146734).
• Cristiano, M.P., Cardoso, D.C., Sandoval‐Gómez, V.E., Simões‐Gomes, F.C. 2020. Amoimyrmex Cristiano, Cardoso, Sandoval, gen. nov. (Hymenoptera: Formicidae): a new genus of leaf‐cutting ants revealed by multilocus molecular phylogenetic and morphological analyses. Austral Entomology 59, 643–676 (doi:10.1111/aen.12493).
• Dahan, R.A., Grove, N.K., Bollazzi, M., Gerstner, B.P., Rabeling, C. 2021. Decoupled evolution of mating biology and social structure in Acromyrmex leaf-cutting ants. Behavioral Ecology and Sociobiology 76, 7 (doi:10.1007/s00265-021-03113-1).
• 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, 369–385 (doi:10.3897/COMPCYTOGEN.V14I3.52726).
• Emery, C. 1888c [1887]. Formiche della provincia di Rio Grande do Sûl nel Brasile, raccolte dal dott. Hermann von Ihering. Bull. Soc. Entomol. Ital. 19: 352-366 (page 357, Combination in Atta (Acromyrmex))
• Emery, C. 1905f. Revisione delle specie del genere Atta appartenenti ai sottogeneri Moellerius e Acromyrmex. Mem. R. Accad. Sci. Ist. Bologna (6)2:39-54 (page 42, Combination in Atta (Moellerius))
• Fowler, H. G. 1988b. Taxa of the neotropical grass-cutting ants, Acromyrmex (Hymenoptera: Formicidae: Attini). Científica (Jaboticabal) 16: 281-295 (page 290, senior synonym of laeviventris)
• Gonçalves, C. R. 1961. O genero Acromyrmex no Brasil (Hym. Formicidae). Stud. Entomol. 4: 113-180 (page 129, see also)
• Jofre, L. E., A. I. Medina, A. G. Farji-Brener, and M. M. Moglia. 2018. The Effect of Nest Size and Species Identity on Plant Selection in Acromyrmex Leaf-Cutting Ants. Sociobiology. 65:456-462. doi:10.13102/sociobiology.v65i3.3263
• Lopes, B.C. 2001. Ecologia comparativa de Acromyrmex striatus (Roger, 1863) e de Cyphomyrmex morschi Emery, 1887 (Formicidae, Myrmicinae, Attini) em dunas da praia da Joaquina, Florianópolis, SC. Tese de Doutorado, Universidade Estadual Paulista, Rio Claro, 191 p.
• Micolino, R., Baldez, B.C.L., Sánchez-Restrepo, A.F., Calcaterra, L., Cristiano, M.P., Cardoso, D.C. 2021. Karyotype structure and cytogenetic markers of Amoimyrmex bruchi and Amoimyrmex silvestrii: contribution to understanding leaf-cutting ant relationships. Genome 651, 43–51 (doi:10.1139/gen-2021-0044).
• 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).
• Mueller, U.G., Ishak, H.D., Bruschi, S.M., Smith, C.C., Herman, J.J., Solomon, S.E., Mikheyev, A.S., Rabeling, C., Scott, J.J., Cooper, M., Rodrigues, A., Ortiz, A., Brandão, C.R.F., Lattke, J.E., Pagnocca, F.C., Rehner, S.A., Schultz, T.R., Vasconcelos, H.L., Adams, R.M.M., Bollazzi, M., Clark, R.M., Himler, A.G., LaPolla, J.S., Leal, I.R., Johnson, R.A., Roces, F., Sosa-Calvo, J., Wirth, R., Bacci, M. 2017. Biogeography of mutualistic fungi cultivated by leafcutter ants. Molecular Ecology 26, 6921–6937 (doi:10.1111/mec.14431).
• Nobua-Behrmann, B. E., J. L. de Casenave, F. A. Milesi, and A. Farji-Brener. 2017. Coexisting in harsh environments: temperature-based foraging patterns of two desert leafcutter ants (Hymenoptera: Formicidae: Attini). Myrmecological News. 25:41-49.
• Roger, J. 1863a. Die neu aufgeführten Gattungen und Arten meines Formiciden-Verzeichnisses nebst Ergänzung einiger früher gegebenen Beschreibungen. Berl. Entomol. Z. 7: 131-214 (page 202, worker, queen, male described)
• Weber, N. A. 1972. Gardening Ants, the Attines. American Philosophical Society, Philadelphia.
• Yela, N.I., Calcaterra, L.A., Aranda-Rickert, A. 2020. Coping with temperature extremes: thermal tolerance and behavioral plasticity in desert leaf-cutting ants (Hymenoptera: Formicidae) across an altitudinal gradient. Myrmecological News 30: 139-150 (doi:10.25849/MYRMECOL.NEWS_030:139).

References based on Global Ant Biodiversity Informatics

• Badano, E.I., H.A. Regidor, H.A. Nunez, R. Acosta and E. Gianoli. 2005. Species richness and structure of ant communities in a dynamic archipelago: effects of island area and age. Journal of Biogeography
• Bicho C. L., M. L. C. Brancao, and S. M. Pires. 2007. Mirmecofauna (Hymenoptera, Formicidae) em hospitais e postos de Saude no municipio de Bagé, RS. Arq. Inst. Biol., São Paulo 74(4): 373-377.
• 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.
• Bruch C. 1914. Catálogo sistemático de los formícidos argentinos. Revista del Museo de La Plata 19: 211-234.
• Cardoso, D.C., T.G. Sobrinho and J.H. Schoereder. 2010. Ant community composition and its relationship with phytophysiognomies in a Brazilian Restinga. Insectes Sociaux 57:293-301
• Cheli G. H., J. C. Corley, O. Bruzzone, M. Brío, F. Martínez, N. M. Roman, and I. Ríos. 2010. The ground-dwelling arthropod community of Península Valdés in Patagonia, Argentina. Journal of Insect Science 10:50 available online: insectsicence.org/10.50
• Claver S., S. L. Silnik, and F. F. Campon. 2014. Response of ants to grazing disturbance at the central Monte Desert of Argentina: community descriptors and functional group scheme. J Arid Land 6(1): 117?127.
• Claver S., and H. G. Gordon. 1993. The ant fauna (Hymenoptera, Formicidae) of the Nacunan Biosphere reserve. Naturalis Sao Paulo 18: 189-193.
• Clemes Cardoso D., and J. H. Schoereder. 2014. Biotic and abiotic factors shaping ant (Hymenoptera: Formicidae) assemblages in Brazilian coastal sand dunes: the case of restinga in Santa Catarina. Florida Entomologist 97(4): 1443-1450.
• Clemes Cardoso D., and M. Passos Cristiano. 2010. Myrmecofauna of the Southern Catarinense Restinga sandy coastal plain: new records of species occurrence for the state of Santa Catarina and Brazil. Sociobiology 55(1b): 229-239.
• Cristiano M. P., D. Clemes Cardoso, T. M. Fernandes-Salomao, and J. Heinze. 2016. Integrating paleodistribution models and phylogeography in the grass-cutting ant Acromyrmex striatus (Hymenoptera: Formicidae) in southern lowlands of South America. PLoS ONE 11(1): e0146734
• 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.
• Diehl-Fleig E. 2014. Termites and Ants from Rio Grande do Sul, Brazil. Sociobiology (in Press).
• Diehl-Fleig, E. and A.M. de Aruajo. 1996. Haplometrosis and pleometrosis in the ant Acromyrmex striatus (Hymenoptera: Formicidae). Insectes Sociaux 43:47-51
• Emery C. 1888. Formiche della provincia di Rio Grande do Sûl nel Brasile, raccolte dal dott. Hermann von Ihering. Bullettino della Società Entomologica Italiana 19: 352-366.
• Emery C. 1906. Studi sulle formiche della fauna neotropica. XXVI. Bullettino della Società Entomologica Italiana 37: 107-194.
• Farji Brener A. G., and A. Ruggiero. 1994. Leaf-cutting ants (Atta and Acromyrmex) inhabiting Argentina: patterns in species richness and geographical range sizes. Journal of Biogeography 21(4): 391-399.
• Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
• Fowler H. G. 1988. Taxa of the neotropical grass-cutting ants, Acromyrmex (Hymenoptera: Formicidae: Attini). Científica (Jaboticabal) 16: 281-295.
• Garcia M., and E. M. Quiran. 2002. Preliminary list of Formicidae (Insecta: Hymenoptera) of Sierra de las Quijadas National Park (San Luis, Argentina). Gayana 66(1): 83-84.
• 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. 1953. La fauna mirmecológica de Bolivia. Folia Universitaria. Cochabamba 6: 211-229.
• Kusnezov N. 1956. Claves para la identificación de las hormigas de la fauna argentina. Idia 104-105: 1-56.
• Kusnezov N. 1957. Die Solenopsidinen-Gattungen von Südamerika (Hymenoptera, Formicidae). Zoologischer Anzeiger 158: 266-280.
• 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.
• Osorio Rosado J. L, M. G. de Goncalves, W. Drose, E. J. Ely e Silva, R. F. Kruger, and A. Enimar Loeck. 2013. Effect of climatic variables and vine crops on the epigeic ant fauna (Hymenoptera: Formicidae) in the Campanha region, state of Rio Grande do Sul, Brazil. J Insect Conserv 17: 1113-1123.
• Pall J. L. M., and E. M. Quiran. 2009. Redescripción de la obrera de Solenopsis leptanilloides (Hymenoptera: Formicidae) y primera cita de la provincia de La Pampa (Argentina). Revista de la Sociedad Entomológica Argentina 68: 381-383.
• Pall J. L., R. G. Kihn, L. C. Arriaga, and E. Quiran. 2011. Report of the epigean arthropod fauna in the "Laguna Don Tomas", Santa Rosa (La Pampa, Argentina). Mun. Ent. Zool. 6(2): 905-911.
• 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.
• Quiran E. M., and A. A. Casadio. 1988. Lista preliminar anotada de los formicidos de la provincia de la Pampa. Rev. Fac. Agronomia UNLPam 3(1): 99-104.
• Rosa da Silva R. 1999. Formigas (Hymenoptera: Formicidae) do oeste de Santa Catarina: historico das coletas e lista atualizada das especies do Estado de Santa Catarina. Biotemas 12(2): 75-100.
• Santschi F. 1916. Formicides sudaméricains nouveaux ou peu connus. Physis (Buenos Aires). 2: 365-399.
• Solomon S. E., C. Rabeling, J. Sosa-Calvo, C. Lopes, A. Rodrigues, H. L. Vasconcelos, M. Bacci, U. G. Mueller, and T. R. Schultz. 2019. The molecular phylogenetics of Trachymyrmex Forel ants and their fungal cultivars provide insights into the origin and coevolutionary history of ‘higher-attine’ ant agriculture. Systematic Entomology 44: 939–956.
• Tizon F. R., D. V. Pelaez, and O. R. Elia. 2010. Effects of firebreaks on ant density (Hymenoptera, Formicidae) in a semiarid region, Argentina. Iheringia, Sér. Zool., Porto Alegre 100(3): 216-221.
• 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.
• Varela, R.O. and R.C. Perera. 2003. Dispersal of Schinus fasciculatus Seeds by the Leaf-Cutting Ant Acromyrmex striatus in a Shrubland of the Dry Chaco, Argentina. Journal of Tropical Ecology 19 (1):91-94
• 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.
• Zolessi L. C. de, Y. P. Abenante, and M. E. de Philippi. 1988. Lista sistematica de las especies de Formicidos del Uruguay. Comun. Zool. Mus. Hist. Nat. Montev. 11: 1-9.
• Zolessi L. C. de; Y. P. de Abenante, and M. E. Philippi. 1989. Catálogo sistemático de las especies de Formícidos del Uruguay (Hymenoptera: Formicidae). Montevideo: ORCYT Unesco, 40 + ix pp.
• de Zolessi, L.C., Y.P. de Abenante and M.E. Philippi. 1987. Lista sistemática de las especies de formícidos del Uruguay. Comunicaciones Zoologicas del Museo de Historia Natural de Montevideo 11(165):1-9
• de Zolessi, L.C., Y.P. de Abenante and M.E. Phillipi. 1989. Catalago Systematico de las Especies de Formicidos del Uruguay (Hymenoptera: Formicidae). Oficina Regional de Ciencia y Technologia de la Unesco para America Latina y el Caribe- ORCYT. Montevideo, Uruguay