Hessea Ormières & Sprague 1973

The type species is H. squamosa Ormi¶res and Sprague, 1973 in gut epithelium of larvae of Sciara sp. (Diptera, Lycoridae). Monomorphic, diplokaryotic and monokaryotic. Meiosis unknown. Transmission unknown. Merogony: diplokaryotic cells develop in contact with host cell cytoplasm and divide by binary fission or by fission of small plasmodia. Sporogony: in thick-walled cysts, 10 - 15 µm, which are dense structures with external hair-like projections into host cell cytoplasm. Mature cysts are ornamented externally by a mosaic of polygonal plaques. The nuclei are paired in the sporont but not appressed as diplokarya. Nuclear and cytoplasmic division within the cyst gives rise to many sporoblasts and spores, many of them teratological. Spores, 2.5 x 1.5 µm, spherical or ellipsoid and usually uninucleate, with a thick exospore and rudimentary endospore. The polar tube arises from an anterior anchoring disc and has 2 - 3 coils around the nucleus. A polaroplast was not described and may not be present. Infection causes hyper-trophy of host cells.