Spiroplasmas were propagated in the Drosophila melanogaster cell line Dm-1. Spiroplasma citri and unidentified strains (corn shunt organism, 277F [tick isolate], powder puff, BNR-1, honey bee, and OBMG) grew to 10(8) to 10(9) colony-forming units per ml and could be passaged. Cytopathic effect (CPE)