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

Fungi in the family Hypocreaceae colonize a wide range of habitats, including the nests of fungus-farming ants ( Attini , the “attines”). Although several Hypocreaceae 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 Apterostigma 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 Manidigitorum gen. nov . and five new species: M. attinorum , M. cervicornutus , M. minutus , M. sessilis , and M. ramosus . Manidigitorum species are distinguished from related Hypocreaceae by their phialidic conidiogenesis arising from an irregular-shaped basal cell resembling a hand supporting fingers. These findings broaden the known diversity of Hypocreaceae and provide new insights into the symbiotic relationships between fungi of this family and attine ants.