Occurrence of Leaf-Cutting and Grass-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae) in Geographic Regions of Brazil

Abstract

Leaf-cutting ants are widely distributed in Brazil, particularly species of the genus Atta. We therefore described the occurrence of leaf-cutting and grass-cutting ant species of the genus Atta. Five routes comprising some of the main highways in the South, Southeast, Center-West, and North of Brazil were sampled, in addition to ants received from other 82 municipalities, composing 300 municipalities sampled. This is the first comprehensive study of Atta in Brazil. The following species were found: A. laevigata, A. capiguara, A. sexdens rubropilosa, A. sexdens piriventris, A. sexdens sexdens and A. cephalotes. Atta laevigata and A. capiguara were the species present in the largest number of the Brazilian municipalities sampled. Atta laevigata assumed the position of species of greatest occurrence in the Brazilian territory. Atta sexdens piriventris was only recorded in the southern region of Brazil. Atta bisphaerica presented lower expansion than A. capiguara. Atta cephalotes and Atta opaciceps are species of very restricted occurrence. Southeastern region was characterized by the occurrence of A. capiguara and A. laevigata. Atta laevigata exhibited a generalized pattern of occurrence in the Center-West and North. Our study contributes to a better understanding of the so far unknown occurrence of leaf-cutting and grass-cutting ants within Brazil.

Interplays between Atta ants (Formicidae: Attini), soils and environmental properties in the Brazilian Neotropics: a preliminary assessment

“…Overlapping of A. sexdens rubropilosa, A. capiguara, and A. bisphaerica does not imply competition. A. sexdens rubropilosa and A. bisphaerica have a positive correlation with TOC and clay content in soils, while A. capiguara have an opposite correlation, also reported by Forti et al (2020). A. s. rubropilosa prefers dicots, while A. capiguara and A. bisphaerica prefer monocots (Fowler et al, 1989;Cabral, 2015;Pereira et al, 2016), and these species are more associated, respectively, with pasture and sugarcane areas.…”

“…As our results indicate, Atta species are well adapted to disturbed landscapes revealing that Atta is a genus resilient to environmental disturbances (Diehl et al, 2017;Segat et al, 2017). These species were associated with young forests (Vasconcelos and Cherrett, 1995;Segat et al, 2017), forest edges (Silva et al, 2018), road edges (Forti et al, 2020), grazing sites (Leite et al, 2018) and open habitats (Dalle Laste et al, 2019;Swanson et al, 2019). This indicates that the wide dispersion of the Atta genus may have been favored by increased degradation of biomes (Siqueira et al, 2017).…”

“…A. cephalotes is closely related to old, mature native forest environments, being an indicator of their conservation status. A. laevigata prefers disturbed habitats, in secondary regenerating process, and A. sexdens sexdens, the most flexible of all species, can be found in both environments (Fowler et al, 1989;Vasconcelos and Cherrett, 1995;Forti et al, 2020).…”

“…A. s. rubropilosa prefers dicots, while A. capiguara and A. bisphaerica prefer monocots (Fowler et al, 1989;Cabral, 2015;Pereira et al, 2016), and these species are more associated, respectively, with pasture and sugarcane areas. This can indicate that replacing natural vegetation and large monoculture monocotyledonous plantations may be an important factor in disseminating and increasing population density of these species (Forti et al, 2020).…”

“…The wide range of A. laevigata in open areas and disturbed habitats (Vasconcelos and Cherrett, 1995;Leite et al, 2018;Forti et al, 2020) may be related to the high abundance of pioneer species with high-nutrient contents in leaves, combined with a lower concentration of secondary chemical compounds that inhibit predation (Vasconcelos and Cherrett, 1995). Also, A. laevigata forages in both monocotyledons and dicots and this may explain its wide distribution in Brazil (Fowler et al, 1989;Vasconcelos and Cherrett, 1995;Vieira-Neto and Vasconcelos, 2010;Siqueira et al, 2017).…”