Four new fungi in the genus Ophiocordyceps have been identified. These fungi belong to a group of “zombifying” fungi that infect ants and then manipulate their behavior, eventually killing the ants after securing a prime location for spore dispersal.
Beyond this important milestone, the paper also draws attention to undiscovered, complex, biological interactions in threatened habitats. The four new species all come from the Atlantic Rainforest of Brazil which is the most heavily degraded biodiversity hotspot on the planet. Ninety-two percent of its original coverage is gone. The effect of biodiversity loss on community structure is well known. What researchers don’t know is how parasites, such as these zombie-inducing fungi, cope with fragmentation. The authors show that each of the four species is highly specialized on one ant species and has a suite of adaptations and spore types to ensure infection. The life-cycle of these fungi that infect, manipulate and kill ants before growing spore producing stalks from their heads is remarkably complicated. The present work establishes the identification tools to move forward and ask how forest fragmentation affects such disease dynamics.
Hidden Diversity Behind the Zombie-Ant Fungus Ophiocordyceps unilateralis: Four New Species Described from Carpenter Ants in Minas Gerais, Brazil. (2011) PLoS ONE 6(3): e17024. doi:10.1371/journal.pone.0017024
Background: Ophiocordyceps unilateralis (Clavicipitaceae: Hypocreales) is a fungal pathogen specific to ants of the tribe Camponotini (Formicinae: Formicidae) with a pantropical distribution. This so-called zombie or brain-manipulating fungus alters the behaviour of the ant host, causing it to die in an exposed position, typically clinging onto and biting into the adaxial surface of shrub leaves. We (HCE and DPH) are currently undertaking a worldwide survey to assess the taxonomy and ecology of this highly variable species.
Methods: We formally describe and name four new species belonging to the O. unilateralis species complex collected from remnant Atlantic rainforest in the south-eastern region (Zona da Mata) of the State of Minas Gerais, Brazil. Fully illustrated descriptions of both the asexual (anamorph) and sexual (teleomorph) stages are provided for each species. The new names are registered in Index Fungorum (registration.indexfungorum.org) and have received IF numbers. This paper is also a test case for the electronic publication of new names in mycology.
Conclusions: We are only just beginning to understand the taxonomy and ecology of the Ophiocordyceps unilateralis species complex associated with carpenter ants; macroscopically characterised by a single stalk arising from the dorsal neck region of the ant host on which the anamorph occupies the terminal region and the teleomorph occurs as lateral cushions or plates. Each of the four ant species collected – Camponotus rufipes, C. balzani, C. melanoticus and C. novogranadensis – is attacked by a distinct species of Ophiocordyceps readily separated using traditional micromorphology. The new taxa are named according to their ant host.