Endophytic fungi increase the processing rate of leaves by leaf‐cutting ants (Atta)

Abstract

1. Fungal endophytes are microfungi that reside asymptomatically inside of leaf tissues, increasing in density and diversity through time after leaves flush. Previous studies have suggested that the presence of fungal endophytes in the harvest material of leaf-cutting ants (Atta colombica, Guérin-Méneville) may negatively affect the ants and their fungal cultivar.2. In the present study, it was tested whether the presence and diversity of fungal endophytes affected the amount of time necessary for leaf-cutter ants to cut, process, and plant leaf material in their fungal garden. It was found that ants took 30-43% longer to cut, carry, clean, and plant leaf tissue with high relative to low endophyte abundance, and that the ants responded similarly to leaf tissue with high or low endophyte diversity.3. It was further investigated whether the fungal cultivars' colonisation rate was greater on leaf material without fungal endophytes. No difference in the ants' cultivar colonisation rate on leaf tissue with high or low endophyte abundance was observed.

Symbiotic fungi alter plant chemistry that discourages leaf‐cutting ants

“…Colletotrichum tropicale influences leaf chemistry and makes leaves less appealing to leaf-cutting ants but likely offers little protection to individual plants as endophyte-colonized leaves are also consumed. Nevertheless, for ants, leaves hosting fungal endophytes take longer to process than those free of the symbiont (Van Bael et al, 2012b), and this additional cost decreases colony development, at least for young colonies whose risk of mortality is the greatest (Van Bael et al, 2012a). It is still an open question whether plant fitness is affected by short-term benefits resulting from ants' food selection or by changes in colony populations resulting from plant-endophyte symbiosis.…”

Comparative analysis of fungal communities in colonies of two leaf-cutting ant species with different substratum preferences

“…On the other hand, Atta capiguara and Atta bisphaerica are typical grass-cutting ants mostly found in pastures and grasslands (Fowler et al, 1986;Garcia, 2005). Regardless of the type of substratum, workers process the plant material which decreases the alien fungal loads and the diversity of fungi before incorporating it into the fungus gardens (Andrade et al, 2002;Van Bael et al, 2009, 2012bDiniz and Bueno, 2010). Exploring the differences between ant species with distinct substratum preference is useful to shed light on whether fungi other than L. gongylophorus are either transients or resident components of attine ant gardens.…”

An Overview of Integrated Management of Leaf-Cutting Ants (Hymenoptera: Formicidae) in Brazilian Forest Plantations

“…Endophytic fungus on plant leaves can also reduce the foraging and processing efficacy of leaf-cutting ants [101,102] probably because of low volatility compounds released after their wounding [103].…”