[Role of phagocytosis and soluble antibacterial factors in experimental immunization of Locusta migratoria].

Last instar larvae of Locusta migratoria can be protected ("vaccinated") against lethal doses of Bacillus thuringiensis by previous injections of low doses of this pathogen. If iron saccharate is injected in to larvae prior to the administration of the "vaccinating" dose of Bacillus thuringiensis, no antibacterial protection can be induced. Injection of iron saccharate in to "vaccinated" larvae does not interfere with the induced protection; such larvae resist lethal doses.