The Council of Agriculture (COA) yesterday introduced a new biological pesticide — Bacillus thuringiensis (Bt) kurstaki E-911, produced by using a bacterium found in the local environment, which the council said was effective in killing the larvae of moths and butterflies while causing no harm to human health.
With research funding from the National Science Council, the COA and the Industrial Development Bureau, the Bt kurstaki E-911 is the first domestically manufactured non-toxic biological pesticide to pass all required inspections for legal registration and a sales permit.
Showing a picture of himself spraying the pesticide in a cabbage farm without wearing a gas mask and gloves, COA Taiwan Agricultural Chemicals and Toxic Substances Research Institute (TACTRI) researcher Tseng Ching-chou (曾經洲) said the new pesticide was toxic to the Lepidoptera order of insects, which includes moths and butterflies, but does not affect other animals.
The Bt is a kind of spore-forming bacterium that produces crystal proteins, and has long been used in other countries as biological pesticides for organic farming, Tseng said, adding that while there are thousands of Bt strains, the strain for producing the Bt kurstaki E-911 was found in storage and it took about 10 years to develop.
He said when the larvae of moths and butterflies — which often eat the leaves of cabbage, rice or cucumbers — consume Bt crystal proteins sprayed on the plants, they die in a state similar to serious gastroenteritis (stomach flu).
Unlike many toxic chemical pesticides that are absorbed by the plant and may remain on the plants for a long time, risking excessive levels of pesticide residue, Tseng said the Bt sprayed on the leaves did not penetrate the plants and would not harm humans even if they ate plants with the pesticide on it.
Although the Bt breaks down readily in the environment, especially under sun and rain, and remains effective for killing the insects for only between four days and a week, he said it was highly recommended for organic farming and improving food safety.
The product has already been patented in the US and is under review for patents in Taiwan and China, the council said.