In vitro propagation of Nosema locustae using fat body cell line derived from Mythimna convecta (Lepidoptera: Noctuidae).

Nosema locustae, a microsporidian parasite of locusts and grasshoppers, was successfully propagated in a fat body cell line from Mythimna convecta (BPMNU-MyCo-1). The fat body cells were grown in MGM-448 medium supplemented with 5% fetal bovine serum and 3% Bombyx mori serum at 25 degrees C. Cultures were inoculated with Nosema spores and agitated for 2 min. Infection appeared 3 days post-inoculation and by 7th day, some cells were filled with spores. At the 15th day post-inoculation, 32% of the fat body cells were infected. After isolation, the spore yield ranged from 1.4 x 10(6) spores/ml. Infected cells were subcultured and by the 4th passage spore production decreased. Harvested spores were found infectious to Locusta migratoria.