A good old ally in the biological fight against some insect species is the Bacillus Thuringiensis, a sporogenous bacterium inhabiting the soil which when ingested by the caterpillars of lepidoptera (especially, but also diptera) neutralizes them paralyzing them in the digestive system.
Distributed on the leaves by spraying in an aqueous dilution, the Bacillus Thuringiensis it is able to counteract even heavy infestations of lepidoptera and diptera without harming pollinating insects (bees and bumblebees), fish, birds and all warm-blooded animals. It is also not phytotoxic and, if used on edible plants, it can be used up to a few days before harvesting.
The singular thing about the Bacillus Thuringiensis is that it can be used both in organic farming, but also in beekeeping in the biological fight against wax moths, and for the creation of transgenic plants capable of autonomously resisting attacks by parasites. A double value that does not make it any less 'organic'.
The 'transgenic' use of Bacillus Thuringiensis it has spread above all in the cultivation of corn and soy after it has been possible to extract and use the gene that encodes the poisonous toxin. Equipped with this gene, cultivated plants are able to synthesize the toxin independently, becoming poisonous for the phytophagous moths who decide to feed on it.
The spores of the Bacillus Thuringiensis they are lethal for over a hundred species of lepidoptera, not all of them therefore; for this reason, before using it, it is necessary to identify the threat well. In the name of the three most common varieties - Kurstaki, Aizawai and Tenebrionis - the Japanese origin of the first discovery (1901) is clearly evident, which was followed by a second independent discovery in Germany in 1911.
Of the Bacillus Thuringiensisof the Kurstaki variety, which is the most widespread on the market, there are seven different strains. Instead, only one strain for the Aizawai variety, of which there are four formulations. One strain only also for the Tenebrionis variety. The latter is used above all in the biological control of beetles.
The Bacillus Thuringiensis it can be used in the biological control of the boxwood defoliator caterpillar (piralyde del bosso - Cidalyma Perspectalis) the phytophagous moth harmful to the boxwood that has been killing hedges in many areas of Northern Italy for some years. For this purpose, the Kurstaki and Aizawai varieties are used.
Bacillus Thuringiensis biological insecticide
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