Ultrastructure of Culicosporella lunata (Microsporida: Culicosporellidae fam. n.) in the mosquito Culex pilosus (Diptera: Culicidae) with new information on the developmental cycle.

The ultrastructural cytology of Culicosporella lunata is described from larvae of its mosquito host Culex pilosus. Diplokaryotic sporonts entered 1 of 12 fundamentally different sporulation sequences that occurred concurrently, each producing morphologically distinctive spores. One involved abortive meiosis and rarely ended with meiospores; the other, the predominant one, involved diplokaryotic sporogonial plasmodia and produced lanceolate, binucleate spores. A previously unknown sporulation sequence in the adult mosquito was found to result in a second type of binucleate spore. The taxonomic affinities of Culicosporella lunata are discussed and because of its distinctive characters, Culicosporellidae fam. n. is created.