Inside Pandora's box: Development of the lethal myrmecopathogenic fungus Pandora formicae within its ant host

Parasites modify their host's appearance, behaviour and physiology to a certain extent. Many of these modifications are seen as purposefully manipulative, serving the parasite's interest. Endgames are particularly intriguing, where the parasite's development requires the host's death. ‘Summit’ or ‘treetop’ disease is one of such spectacular examples of parasite-induced death: the host dies attached to an elevated part of the vegetation. Many organisms induce summit disease including Ophiocordyceps, Entomophthora and Pandora species. We analyzed the development of Pandora formicae inside its ant host's body after the host's death. Our findings suggest that the fungus consumes the host's muscles and central nervous system quite fast, similarly to the related Entomophthora muscae. Unlike in Ophiocordyceps, no conidial anastomosis tubes were observed. Differences and similarities between the three fungi are discussed with regard to the extent of parasitic manipulation since Pandora's manipulative traits seem less pronounced than in Ophiocordyceps.