Typical intracranial myiasis in Nigerian red river hogs () caused by an unknown bot fly (Diptera: Oestridae).

We report an unknown taxon of bot fly (Diptera: Oestridae: Oestrinae) in red river hogs ( Linnaeus, 1758) in Cross River State, Nigeria. From direct observation and interviews with local hunters, we document that, remarkably, the parasite typically occurs within the intracranial supra-meningeal space - i.e., between the inner wall of the skull and the brain - but without causing visible inflammation or clinical signs. The parasite is most similar (up to 87.9%) to based on cytochrome oxidase subunit 1 DNA sequencing but is sufficiently divergent phylogenetically to represent a new or previously un-sequenced taxon. Morphologically, the parasite shares some, but not all, features with . Local cultural belief systems attribute aspects of red river hog behavior (e.g. intelligence, elusiveness) to the parasite, suggesting a prolonged presence in the red river hog population. The parasite's unusual anatomic location may be aberrant, or it may be a protective adaptation to life in red river hogs, which forage vigorously with their snouts.