New Light on the Systematics of Fungi Associated with Attine Ant Gardens and the Description of Escovopsis kreiselii sp. nov.

Abstract

Since the formal description of fungi in the genus Escovopsis in 1990, only a few studies have focused on the systematics of this group. For more than two decades, only two Escovopsis species were described; however, in 2013, three additional Escovopsis species were formally described along with the genus Escovopsioides, both found exclusively in attine ant gardens. During a survey for Escovopsis species in gardens of the lower attine ant Mycetophylax morschi in Brazil, we found four strains belonging to the pink-colored Escovopsis clade. Careful examination of these strains revealed significant morphological differences when compared to previously described species of Escovopsis and Escovopsioides. Based on the type of conidiogenesis (sympodial), as well as morphology of conidiogenous cells (percurrent), non-vesiculated conidiophores, and DNA sequences, we describe the four new strains as a new species, Escovopsis kreiselii sp. nov. Phylogenetic analyses using three nuclear markers (Large subunit RNA; translation elongation factor 1-alpha; and internal transcribed spacer) from the new strains as well as available sequences in public databases confirmed that all known fungi infecting attine ant gardens comprise a monophyletic group within the Hypocreaceae family, with very diverse morphological characteristics. Specifically, Escovopsis kreiselii is likely associated with gardens of lower-attine ants and its pathogenicity remains uncertain.

The molecular phylogenetics ofTrachymyrmexForel ants and their fungal cultivars provide insights into the origin and coevolutionary history of ‘higher‐attine’ ant agriculture

“…The specialized fungal parasites in the genus Escovopsis Muchovej and Della Lucia (Ascomycota: Hypocreales), which are found only in association with attine nests and which compete with the ants to feed on the fungal cultivars, are only partially known for species in these genera. To date, studies have focused on Escovopsis species associated with four Mycetomoellerius species [M. zeteki (Weber), M. ruthae (Weber), M. dichrous (Kempf), M. atlanticus (Mayhé-Nunes and Brandão)] and one Paratrachymyrmex species (P. diversus) (Currie et al, 1999a;Currie et al, 2003a;Meirelles et al, 2014Meirelles et al, , 2015Birnbaum & Gerardo, 2016).…”

“…Five distinct agricultural systems have been recognized. Each is broadly characterized by associations between phylogenetic groups (clades or grades) of ants and corresponding phylogenetic groups of fungi that are parasitized by phylogenetic groups of parasitic ascomycete fungi in the genus Escovopsis, as well as by the substrate upon which the fungi are cultivated (Weber, 1972;Gerardo et al, 2004Gerardo et al, , 2006Schultz & Brady, 2008;Mehdiabadi & Schultz, 2010;Meirelles et al, 2015;Birnbaum & Gerardo, 2016). Of these, undoubtedly the most celebrated are the 52 described species of leaf-cutting ants in the genera Acromyrmex Mayr and Atta Fabricius (Hölldobler & Wilson, 1990;Hölldobler & Wilson, 2011;Rabeling et al, 2015).…”

Shared Escovopsis parasites between leaf-cutting and non-leaf-cutting ants in the higher attine fungus-growing ant symbiosis

“…Finally, three other Hypocreaceae fungi used as an outgroup by Meirelles et al . [ 21 ] were maintained here. The final dataset comprised two files, one for tef1 with 85 taxa and the other for ITS with 80 taxa (for the five Escovopsis strains derived from Gerardo et al .…”

Fungal communities in gardens of the leafcutter ant Atta cephalotes in forest and cabruca agrosystems of southern Bahia State (Brazil)

“…For PCR, the 25 mL reaction volumes consisted of: 1.25 mM of each dNTP, 5.0 mL of buffer 5Â, 2.0 mL of MgCl 2, 1.5 mL of each primer and 0.2 mL of Taq polymerase. PCR conditions followed Meirelles et al (2015) and amplicons were cleaned using Wizard Ò SV Gel and PCR Clean-Up System (Promega). Sequences were bidirectionally sequenced using BigDye Ò Terminator v.3.1 Cycle Sequencing kit (Life Technologies) in an ABI 3330 sequencer (Life Technologies).…”