Technical Abstract: Naturally occurring protozoan parasites (microsporidia) of mosquitoes are under study to evaluate and develop these disease causing organisms as biological control agents. Confusion has existed for more than a quarter of a century concerning the correct name-author-date combination for the phylum name of this group. An intensive study of the problem by scientists at the University of Maryland and the Center for Medical, Agricultural and Veterinary Entomology has concluded that only MICROSPORIDIA Balbiani, 1882, can be the correct spelling of the phylum name and author and date. Clarification of this problem is of interest to protozoologists generally and to microsporidiologists specifically.