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:XTOXN1-1-PIP-BACILLUS f I IURINGIENSIS Itip://ace.orst.cdu/cgi-bin/int's/01/pips/bacillus.htm EXTOXNET Extension Toxicology Network Pesticide Information Profiles A Pesticide Information Project of Cooperative Extension Offices of Cornell University, Oregon State University, the University of Idaho, and the University of California at Davis and the Institute for Environmental Toxicology, Michigan State University. Major support and funding was provided by the USDA/Extension Service/National Agricultural Pesticide Impact Assessment Program. EXTOXNET primary files maintained and archived at Oregon State University Revised June 1996 Bacillus thuringiensis Trade and Other Names: Trade names include Acrobe, Bactospeine, Berliner (variety kurstaki), Certan (variety aizawai), Dipel, Javelin, Leptox,Novabac, Teknar (variety israelensis), Thuricide, and Victory. Bacillus thuringiensis is also known at B.t. Regulatory Status: This microbial insecticide was originally registered in 1961 as a General Use Pesticide (GUP). It is classified as toxicity class III - slightly toxic. Products containing B.t. bear the Signal Word CAUTION because of its potential to irritate eyes and skin. Chemical Class: bacterium Introduction: Bacillus thuringiensis(B.t.) is a naturally-occurring soil bacterium that produces poisons which cause disease in insects. B.t. is considered ideal for pest management because of its specificity to pests and because of its lack of toxicity to humans or the natural enemies of many crop pests. There are different strains of B.t., each with specific toxicity to particular types of insects: B.t. aizawai (B.t.a.) is used against wax moth larvae in honeycombs; B.t. israelensis (B.t.i.) is effective against mosquitoes, blackflies and some midges; B.t. kurstaki (B.t.k.) controls various types of lepidopterous insects, including the gypsy moth and cabbage looper. A newer strain, B.t. san diego, is effective against certain beetle species and the boll weevil. To be effective, B.t. must be eaten by insects during their feeding stage of development, when they are larvae. B.t. is ineffective against adult insects. More than 150 insects, mostly lepidopterous larvae, are known to be susceptible in some way to B.t. B.t. forms asexual reproductive cells, called spores, which enable it to survive in adverse conditions. During the process of spore formation, B.t. also produces unique crystalline bodies. When eaten, the spores and crystals of B.t. act as poisons in the target insects. B.t. is therefore referred to as a stomach poison. B.t. crystals dissolve in the intestine of susceptible insect larvae. They paralyze the cells in the gut, interfering with normal digestion and triggering the insect to stop feeding on host plants. B.t. spores I of 5/11/004:15 PM