Endoreticulatus W. M. Brooks, J. J. Becnel & G. G. Kennedy 1988

Monomorphic, monokaryotic throughout life cycle; transmission probably per os and direct; meronts are surrounded by a close-fitting cisterna of host cell endoplasmic reticulum; meronts are moniliform or irregular with one to several isolated nuclei, and divide to give uninucleate products; sporonts withdraw within the cisterna of, to lie within a double-walled parasitophorous vacuole, with the lumen containing finely granular or sparse tubular metabolic products; Sporonts become plasmodia, which divide by successive cleavages, producing up to 30 or more spores; spores, 2.6 x 1.5 µm, ovocylindrical to reniform and uninucleate, are frequently liberated from the parasitophorous vacuoles; polar tube is isofilar with about 6 coils; polaroplast not described. E. fidelis causes premature death in laboratory colonies of the host; type species E. fidelis (Hostounsky and Weiser, 1975) Brooks, Becnel and Kennedy, 1988 in midgut epithelium of Leptinotarsa undecimlineata (Coleoptera, Chrysomelidae).