Date of Completion

Summer 8-31-2021

Project Advisor(s)

Chris Simon; Rachel O'Neill; Paul Lewis; Jonathan Klassen

University Scholar Major

Ecology and Evolutionary Biology


Entomology | Evolution | Genomics | Molecular Genetics


Nutritional symbioses are integral to the survival and diversity of many insects. The majority of herbivorous insects in the order Hemiptera possess stable, inherited symbionts that produce essential amino acids and vitamins. However, instability has been observed in cicadas, with one bacterial symbiont, Hodgkinia cicadicola, being repeatedly replaced by a new fungal symbiont, Ophiocordyceps. The fungal symbionts are thought to be derived from parasitic Ophiocordyceps species, but little is known about these parasitic ancestors or how the transition from parasite to mutualist occurs. We used a combination of targeted amplified genes and metagenomic sequencing to investigate the evolution of endosymbiotic Ophiocordyceps across 25 species of cicadas in the tribe Cryptotympanini. At least four parallel instances of Ophiocordyceps domestication were found in the studied group, arising from a single monophyletic clade of cicada-parasitic Ophiocordyceps with only one having been known previously. The genome of a symbiotic Ophiocordyceps strain from the cicada Megatibicen auletes has been sequenced and annotated, paving the way for future comparative analyses between symbiotic and parasitic Ophiocordyceps.