Infection and development of Nosema sp. NIS H5 (Microsporida: Protozoa) in several lepidopteran insects.
Nosema sp. NIS H5 infection and development in an A. eucalypti cell line were compared with N. bombycis. No differences in A. eucalypti infection rate were observed between the Nosema species by 48 h post-inoculation. The spread of infection in the cell culture with Nosema sp. NIS H5 was slower than that of N. bombycis from 96 h post-inoculation onward. At 120 h post-inoculation, cell infection was 16 and 22% with Nosema sp. NIS H5 and N. bombycis, respectively. Morphological changes during development were similar in both Nosema species, but from 96 h post-inoculation onward, Nosema sp. NIS H5 sporogenesis was slower than that of N. bombycis. Infectivity tests revealed that N. bombycis was infectious to B. mori, B. mandarina, A. pernyi, A. yamamai, Hemerophila atrilineata [Phthonandria atrilineata], Spilarctia imparilis [Lemyra imparilis], Hyphantria cunea, Glyphodes pyloalis [Diaphania pyloalis], Leucania separata [Mythimna separata], Spodoptera litura and Pieris rapae crucivora, but was not infectious to Lymantria dispar and Euproctis similis [Sphrageidus similis]. Nosema sp. NIS H5 was infectious to all species except B. mori and was lethally infectious to M. separata. It is concluded that the wide lepidopteran host range of Nosema sp. NIS H5, combined with its non-infectivity to B. mori makes Nosema sp. NIS H5 become a promising biological control agent for insect pests, especially in sericultural areas.