More diverse than previously thought: a novel Hypocreaceae symbiont from Apterostigma fungus-farming ants

Fungi in the family <i>Hypocreaceae</i> colonize a wide range of habitats, including the nests of fungus-farming ants (<i>Attini</i>, the "attines"). Although several <i>Hypocreaceae</i> genera are known from attine ant nests, recent studies indicate an even greater, previously unrecognized diversity. In this study, we describe a new genus and five new species associated with <i>Apterostigma</i> ants. A total of 11 isolates from Brazil, Ecuador, and Panama were examined based on macro- and micromorphological characteristics, combined with a family-wide phylogenetic analysis using five molecular loci. This polyphasic approach supports the recognition of <i>Manidigitorum</i> <b>gen. nov</b>. and five new species: <i>M. attinorum</i>, <i>M. cervicornutus</i>, <i>M. minutus</i>, <i>M. sessilis</i>, and <i>M. ramosus</i>. <i>Manidigitorum</i> species are distinguished from related <i>Hypocreaceae</i> by their phialidic conidiogenesis arising from an irregular-shaped basal cell resembling a hand supporting fingers. These findings broaden the known diversity of <i>Hypocreaceae</i> and provide new insights into the symbiotic relationships between fungi of this family and attine ants.