TOXICITY OF BACILLUS-THURINGIENSIS SUBSP AIZAWAI FOR MAMESTRA-CONFIGURATA (LEPIDOPTERA, NOCTUIDAE)

Fifty-one strains of Bacillus thuringiensis subsp. aizawai were screen ed for toxicity against the bertha armyworm, Mamestra configurata Walk er. The strain, NRRL-HD133 was selected for studies on synergism with other subspecies of B, thuringiensis. HD133 was highly toxic to M, con figurata compared with the international standard (HD-1S-1980) and was synergistic with B. thuringiensis subsp. kurstaki (HD262), B, thuring iensis subsp, kenyae (HD551), and HD262 plus HD551 when powders were f ed to 3rd instars in artificial diet. When the strains were cultured t ogether only HD133 and HD551 were synergistic.