Some strains of Bt toxins are also toxic to nematodes. Common types of Bt strains: Bt israelensis controls immature mosquitos, flies, and gnats. Bt aizawai and Bt kurstaki controls caterpillars of moths and butterflies.

Bacillus thuringiensis produce protein crystals during a particular phase of their growth that kill certain insects such as lepidopterans (tobacco budworm, armyworm), coleopterans (beetles) and dipterans (flies, mosquitoes).

Over two decades of review, the EPA and numerous scientific bodies have consistently found that Bt and engineered Bt-crops are not harmful to humans. What is Bt? Bacillus thuringiensis (often referred to as simply “Bt”) is a common, naturally occurring bacterium found in soils and on plant leaves worldwide.

Bt strain have been used to design bioinsecticidal plants through genetic engineering.