History

    Bacillus thuringiensis was first discovered in 1901 by a Japanese biologist named Shigetane Ishiwatari. He discovered this when he was researching Sudden Collapse Disease, that afflicted silkworms. It was later made known that B. thuringiensis was responsible for this. This discovery was forgotten until Ernst Berliner rediscovered B. thuringiensis it in 1911. He was researching the cause for the death of moths in the German town of Thuringia. This is where the name thuringiensis came from. Originally the bacteria had been called Bacillus sotto by Ishiwatari, but this was overruled after Berliner’s discovery. Berliner discovered the crystal inside the bacteria but it was unknown what the crystal did until later. Bacillus Thuringiensis was unused in the mainstream market until 1920 when farmers were reported to spray it on their fields. Finally in 1938, France started to market these bacteria to farmers as Sporine. This was marketed to kill flour moths.

    The Bt products were limited at this point. Products like sprays washed away in the rain or degraded under the sun's UV rays. Also, many insects were immune to the strains known at the time. Only lepidopteran (moth) larvae were susceptible to the Sporine.

    In 1956 scientists discovered how B. thuringiensis worked. It was not the bacteria itself, but the crystals inside it. The scientists that discovered this were Hannay, Angus, and Fitz-James. Studying the crystals suddenly became a main focus of the Bt research. 1958 marked the year when Bt was commercially available to an American market. In 1968 Bacillus thuringiensis was finally registered as a commercial pesticide by the EPA.

    Only thirteen strains of Bt were discovered by 1977. All of these strains were only toxic to certain strains of moth larvae. In this year other strains of Bt were found. These strains were toxic to more damaging pests like flies and beetles. The use of Bt increased in the 1980's when many insects became resistant to cheaper synthetic insecticides. Also, environmental researchers began to realize that synthetic insecticides were harming the environment. This was a push forward for Bt, which does not stay in the environment after use, but rather dissipates. The government now began to fund research on Bt.

    With the advances in molecular biology, scientists started making genetically engineered corn and other plants. They put the DNA that encodes the crystal in Bt into the corn. The first record of this was in 1995. Now, countries all over the world grow genetically modified crops like cotton or potatoes.

Picture is credited from <http://www.bt.ucsd.edu/bt_history.html>