{"id":370,"date":"2026-08-18T16:08:14","date_gmt":"2026-08-18T15:08:14","guid":{"rendered":"https:\/\/www.coltivobio.com\/en\/?p=370"},"modified":"2026-08-18T16:08:14","modified_gmt":"2026-08-18T15:08:14","slug":"bacillus-thuringiensis","status":"publish","type":"post","link":"https:\/\/www.coltivobio.com\/en\/bacillus-thuringiensis\/","title":{"rendered":"Bacillus thuringiensis insecticide: everything you need to know"},"content":{"rendered":"

Bacillus thuringiensis is used to produce a highly valued biological and natural insecticide in agriculture. In this technical sheet, we will look at the mode of action, characteristics and use of this important insecticide derived from a bacterium.<\/strong><\/p>\n

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What is Bacillus thuringiensis and how to use it correctly<\/strong><\/span><\/h2>\n

Bacillus thuringiensis<\/em> (commonly abbreviated as B.t.) is used to produce one of the most important biological insecticides, which is also successfully used in conventional agriculture. Bacillus thuringiensis<\/em> is a spore-forming Gram-positive bacterium characterised by the production of a protein crystal containing a toxin, the delta-endotoxin. B.t. is active against many species of insects, from Diptera and Lepidoptera to Coleoptera, but in agriculture the main target remains Lepidoptera. Bacillus thuringiensis<\/em>, as a natural insecticide, is active only by ingestion and against insect larvae in their youngest stages. This means that treatment must be carried out when first-instar larvae appear, as this is the larval stage most sensitive to the toxin. Hence the importance of monitoring infestations in the field in order to intervene at the most appropriate time. Bacillus thuringiensis<\/em>, as a biological insecticide, has no effect on eggs, and adults are almost completely resistant. The mode of action of Bacillus thuringiensis<\/em> is due to the toxicity of a protein crystal that forms when the bacterium sporulates. When the protein crystal reaches the intestine of the target insect larva through ingestion, it comes into contact with the digestive juices and, in the highly alkaline environment (pH 9.5\u201312), the crystal dissolves, releasing the delta-endotoxin. This toxin causes paralysis of the muscles of the digestive and mouthparts. As a result, the larva stops feeding (within less than one hour after ingestion). In the most sensitive species, death can occur within a short period when the midgut epithelium is irreparably destroyed, while in more tolerant species death generally occurs a few days later. In this case, B.t. spores germinate, resulting in death from septicaemia or starvation. This product is completely harmless to mammals, including humans. Bacillus thuringiensis<\/em> is successfully used against:<\/p>\n