Abstract
Bacterial cells were isolated from dead larvae of the mulberry tiger moth, Spilosoma imparilis BUTLER, in a mulberry field in September, 1979. Staining properties, culture conditions, election microscopic and histophathological observations of host tissues suggested that these bacteria are facultive anaerobe gram-negative bacteria multiplying in the cytoplasm of the midgut. Bacteriological characterization showed that the microorganism was an Enterobacter sp. To confirm the pathogenicity, the bacteria were orally inoculated to eight families and 16 species of lepidopterous larvae. i.e. Spilosoma subcarnea, Hyphantria cunea, Stigmatophora flave, Eilema fuscodorsalis, Eupractis similis, Laelia coenosa sangica, Lymantria dispa japonica, Malacosoma neustria testacea, Pieris rapae crucivora, Plusia nigrisigna, Clostera anastomosis orientalis, Bombyx mori, Theophila mandarina, etc. In 13 species belonging to seven families the larvae were infected, whereas in three species, Lymantria dispar japonica. Glyphodes pyloalis and Hellula undali, they were not infected. The bacterial cells were found to multiply in the cytoplasm of the midgut of all the infected larvae.
