Bt toxin

References

Bt toxin

chemical compound

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 21, 2026

Quick Summary

Bt toxin is a chemical compound produced by the soil-dwelling bacterium Bacillus thuringiensis (Bt). This toxin is fatal to certain herbivorous insects and has been used as an insecticide since the 1920s, particularly in organic farming.1

Bt is also used to genetically modify food crops, enabling them to produce the toxin themselves and deter pests. The toxin is lethal to various insects, including butterflies, moths, flies, and beetles, with different Bt strains targeting specific insect orders.1

When susceptible insects ingest Bt toxin, it blocks their digestive system, leading to starvation or rupture. Unlike many chemical insecticides, Bt is specific to certain insects and is considered non-toxic to humans and other mammals. However, concerns exist regarding potential allergenicity and the development of insect resistance to the toxin.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

agricultural sciences
Emerging agricultural sciences
…produces a natural insecticide called Bt toxin. However, some insect pests have gained resistance to the toxin, and synthetic pesticides are needed to supplement the Bt crops in some places. Herbicide-resistant crops (HRC) have been available since the mid-1980s; these crops enable fairly effective chemical control of weeds, since generally…
Read More
…produces a natural insecticide called Bt toxin. However, some insect pests have gained resistance to the toxin, and synthetic pesticides are needed to supplement the Bt crops in some places. Herbicide-resistant crops (HRC) have been available since the mid-1980s; these crops enable fairly effective chemical control of weeds, since generally…
Read More

bacillus
…gene controlling production of the Bt toxin in B. thuringiensis has been used in the development of GM crops such as Bt cotton (see genetically modified organism).
Read More
…gene controlling production of the Bt toxin in B. thuringiensis has been used in the development of GM crops such as Bt cotton (see genetically modified organism).
Read More

Bacillus thuringiensis
…bacterium that naturally produces a toxin that is fatal to certain herbivorous insects. The toxin produced by Bacillus thuringiensis (Bt) has been used as an insecticide spray since the 1920s and is commonly used in organic farming. Bt is also the source of the genes used to genetically modify a…
Read More
…bacterium that naturally produces a toxin that is fatal to certain herbivorous insects. The toxin produced by Bacillus thuringiensis (Bt) has been used as an insecticide spray since the 1920s and is commonly used in organic farming. Bt is also the source of the genes used to genetically modify a…
Read More

genetically modified organism
GMOs in agriculture
…produces a natural insecticide called Bt toxin. Field studies conducted in India in which Bt cotton was compared with non-Bt cotton demonstrated a 30–80 percent increase in yield from the GM crop. This increase was attributed to marked improvement in the GM plants’ ability to overcome bollworm infestation, which was…
Read More
…produces a natural insecticide called Bt toxin. Field studies conducted in India in which Bt cotton was compared with non-Bt cotton demonstrated a 30–80 percent increase in yield from the GM crop. This increase was attributed to marked improvement in the GM plants’ ability to overcome bollworm infestation, which was…
Read More

diamondback moth
…pest to develop resistance to Bt toxin, a plant-expressed insecticide that occurs in crops genetically modified to carry the Bt-producing gene from the bacterium Bacillus thuringiensis. Transgenic sexing, in which males are engineered to carry a gene that prevents the maturation and reproduction of female offspring, has been explored as…
Read More
…pest to develop resistance to Bt toxin, a plant-expressed insecticide that occurs in crops genetically modified to carry the Bt-producing gene from the bacterium Bacillus thuringiensis. Transgenic sexing, in which males are engineered to carry a gene that prevents the maturation and reproduction of female offspring, has been explored as…
Read More