A field experiment was conducted at Yuma, AZ, with microbial insecticides for control of the tobacco budworm. Effectiveness of Bacillus thuringiensis Berliner, alone or in combination with other materials, was emphasized. Greatest effectiveness was achieved when B.t. was combined with Fundal or Pounce. Intermediate results occurred when the microbial treatments were applied alone and the untreated check resulted in almost total crop destruction. Addition of the feeding stimulant, COAX, improved control in almost all cases.