文摘
A new type of insecticidal parasporal body is reported from Bacillus thuringiensis subspecies kenyae (H4a4c) isolated from maize dust in Mexico. This parasporal body is spherical to oblong and composed of three inclusions, one spherical, one cuboidal, and one bipyramidal. Together, these contain four major proteins, three in the CryI size class (138, 133, and 131 kDa), and one in the CryII size class (65 kDa). Monoclonal antibodies that recognize CryIB reacted with the 138-kDa protein, but those that recognize CryIA(a) or CryIA(a) and CryIA(b) did not react with any of the proteins. This isolate was more toxic (LC50 = 96 ng cm−2 diet) to first instars of the diamond back moth, Plutella xylostella, than the HD1 isolate ofB. thuringiensis subsp. kurstaki (LC50 = 182 ng cm−2 diet).