The introduction of integrated pest management in the Ethiopian horticultural sector : Bacillus thuringiensis strains and its toxicity

1 Introduction As hazards of conventional broad acting pesticides are documented, researchers, poli cymakers and growers look for pesticides that are toxic only to the target pest, have no impact on other such as beneficial species, and have fewer environmental effects. Bacillus thuringiensis (Bt) insecticides results from this research and is a typical example as one of the components in an IPM approach. Among the various Bt strains insectic idal activity is specific. However, care is warranted in its use because depending on the Bt strain an d production method e.g. non-specific heat -stable exotoxines (s ometimes,structurally similar to a nucleotide) can be produced which can have negati ve side effects. So far dete ctable levels of ß-exotoxin are not allowed in B. thuringiensis products in Western Europe and North America. Out of concern for mammalian toxicity, the World Health Organization (1999) addressed no n-specific thuringiensin from different subspecies of Bt to promote human health, and regulated Bt strains that produced thuringiensin.