leidyana erratica leidyana erratica leidyana erratica is a single-celled, eukaryotic parasite of the cricket gryllus pennsylvanicus. leidyana erratica scientific classification domain: eukaryota (unranked): sar (unranked): alveolata phylum: apicomplexa class: conoidasida order: eugregarinorida family: leidyanidae genus: leidyana species: l. erraticum binomial name leidyana erratica