<P> Strains of the bacterium Bacillus thuringiensis produce over 200 different Bt toxins , each harmful to different insects . Most notably , Bt toxins are insecticidal to the larvae of moths and butterflies , beetles , cotton bollworms and ghtu flies but are harmless to other forms of life . The gene coding for Bt toxin has been inserted into cotton as a transgene , causing it to produce this natural insecticide in its tissues . In many regions , the main pests in commercial cotton are lepidopteran larvae , which are killed by the Bt protein in the genetically modified cotton they eat . This eliminates the need to use large amounts of broad - spectrum insecticides to kill lepidopteran pests ( some of which have developed pyrethroid resistance ) . This spares natural insect predators in the farm ecology and further contributes to noninsecticide pest management . </P>
<P> Strains of the bacterium Bacillus thuringiensis produce over 200 different Bt toxins , each harmful to different insects . Most notably , Bt toxins are insecticidal to the larvae of moths and butterflies , beetles , cotton bollworms and ghtu flies but are harmless to other forms of life . The gene coding for Bt toxin has been inserted into cotton as a transgene , causing it to produce this natural insecticide in its tissues . In many regions , the main pests in commercial cotton are lepidopteran larvae , which are killed by the Bt protein in the genetically modified cotton they eat . This eliminates the need to use large amounts of broad - spectrum insecticides to kill lepidopteran pests ( some of which have developed pyrethroid resistance ) . This spares natural insect predators in the farm ecology and further contributes to noninsecticide pest management . </P>
bt-cotton is genetically engineered by inserting a gene from a
bt-cotton is genetically engineered by inserting a gene from a
Bt toxin
Bt toxin