A Guide to the Genus Cordyceps and Potential Future Host Jump Possibilities

Abstract

Cordyceps sp. is one of the oldest fungal genera on Earth, with records of its existence stretching as far back as the 17th century - prior to the establishment of Linnaean taxonomy. It is an entomopathogen - a parasite that specializes on a variety of different insect species - that exerts an extreme burden of virulence and mortality on its hosts. Literature on Cordyceps is broad but disorganized; many sources share conflicting information as to the definition of various Cordyceps subgenera or the traits of various species. The first purpose of the present study is to collate information about many of the most prominent taxa in the genus Cordyceps. The second objective is to make predictions as to the potential of various Cordyceps species to undergo host jump and parasitize new hosts. To this end, I have proposed a model to determine trait similarity between different species of Cordyceps. Based on the work of Nikoh and Fukatsu (2000), which suggests host jump occurred between the species C. paradoxa (parasitizes cicadas) and C. ophioglossoides (parasitizes Elaphomyces) on the basis of morphological similarities and phylogenetic proximity, the present study employs a model to use such trait similarity to predict future host jump patterns. Predicting these patterns in Cordyceps may become increasingly useful as faith in Cordyceps as both a biopesticide and a medicinal agent increases throughout the scientific community. Additionally, the present study may serve as an honest assessment of the limitations on Cordyceps and its ability - or lack thereof - to redefine its pathogenicity through extra-kingdom host jumps.