Entomopathogenic fungi in the clade Ophiocordyceps unilateralis (s.l.) parasitize formicine ants (more commonly known as carpenter ants), resulting in fungal fruiting bodies that emerge from the head of the infected ant. This phenomenon is better known as the “zombie-ant fungus.” In Oak Ridge, Tennessee, 191 infected ant specimens found on deciduous understory shrubs and saplings were collected from May to December 2022 and from March to May 2023. The diameter of stems on which these infected ants were attached was measured, host plant species were determined, and various morphologic characteristics (e.g., stroma length and perithecial plate diameter) of this fungus were documented. Deoxyribonucleic acid extractions and polymerase chain reaction analysis were conducted to confirm the identity of the fungus. Our results confirmed the presence of a fungal species within the Ophiocordyceps clade. Ophiocordyceps kimflemingiae was found infecting Camponotus americanus Mayr attached to stems of several understory shrubs and saplings, such as Lindera benzoin (L.) Blume (spicebush), Ulmus spp. (elm), Acer spp. (maple), Betula spp. (birch), and others. The size of fungal morphologic characteristics varied widely. For example, fungal stroma length ranged from <1 to >30 mm and perithecial plate diameter ranged from as small as 0.1 to >1.5 mm. This research has expanded the known geographic distribution of this fungus, demonstrated fungal morphologic variation, contributed to ecologic knowledge on stem diameter and mandibular death grip of infected ants on deciduous host plants, and expanded the listing of known plant species inhabited by infected ants.Abstract
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