Bacillus thuringiensis, Berliner is well-known for use as a microbial insect pathogen useful against leaf-chewing insects such as the alfalfa caterpiller, the cosmopolitan green beetle, the European corn borer and Mediterranean flower moth. See, for example, U.S. Pat. 3,150,062. Although used for the toxic effects on general agricultural and forest leaf-chewing insect pests, Bacillus thuringiensis, Berliner has no substantial effect on sucking insects such as aphids and the like.
The search has continued for ways to increase the potency, toxicity and/or persistance of insecticides including Bacillus thuringiensis, Berliner. It has been proposed, for example, in Chemical Abstracts, 28409v, Vol. 79, p. 148 (1973) to mix Bacillus thuringiensis with equal amounts of a synthetic pyrethroid insecticide. Such mixtures, however, have been found undesirable since, for example, while Bacillus thuringiensis is exempt from tolerance levels, the synthetic pyrethroid insecticide is not and the resulting mixture containing a synthetic pyrethroid insecticide also is not exempt.
The search has continued for a more efficacious manner of utilizing Bacillus thuringiensis, Berliner as a general insecticide.