Isolation and Characterization of Nosema bombycis (Microsporida: Nosematidae) from Larvae of Beet Armyworm, Spodoptera exigua

A microsporidian infection causing high mortality levels was found in the larvae of the beet armyworm, Spodoptera exigua reared on an artificial diet. Dead larvae contained a large number of microsporidian spores with a similar morphology to that of Nosema bombycis NIS 001. The microsporidian from S. exigua, designated N. sp. Y9101, was transmitted to the next generation of S. exigua via eggs. The rate of spore germination under various stimulated conditions was similar between N. sp. Y9101 and N. bombycis NIS 001. When studied by the latex adhesion test using latex particles sensitized with various species of monoclonal and polyclonal antibodies, spores of N. sp. Y9101 reacted with latex particles sensitized with antibodies against N. bombycis NIS 001 spores. Growth and development of N. sp. Y9101 and N. bombycis NIS 001 in Antheraea eucalypti cell cultures seemed similar. On the basis these data, N. sp. Y9101 was determined to be a strain of N. bombycis.