Bt – a product from nature
Insects can cause severe damage to agricultural crops. In traditional agriculture
they are targeted with an arsenal of insecticides. Some of these are harmful to
humans and the environment. However, there are also more environmentally
friendly alternatives, such as the toxins produced by the soil bacterium Bacillus
thuringiensis (usually abbreviated to “Bt”). These Bt proteins are only toxic to some
moth and butterfly caterpillars and/or larvae of beetles and mosquitoes. They are
harmless to other animals, including humans.
Biotechnology was used to insert the genes that code for the Bt proteins into the
DNA of agricultural crops such as corn and cotton. This resulted in the names Bt
corn and Bt cotton. These toxins make Bt corn more resistant to being eaten by
– for example – the larvae of the corn borer and Bt cotton more resistant against
the bollworm. The use of Bt as a spraying agent is permitted in organic farming,
but when Bt is sprayed it also kills sensitive insects that do not feed on the plant.
Enabling crops to produce Bt themselves means that only the insects that feed on
the crop are killed.