But what they don't tell you is how the genes for Bt that are inserted into the plant's DNA are critically different from the Bt that occurs in nature. In its natural form, the Bt bacteria contains a long crystallized protein, which must be partially digested in an insect's stomach before it releases the active toxin, which punches holes in the insect's digestive tract and kills it. It is this short toxic form of the protein that has been engineered into plants. However, this active toxin will only be created in the guts of certain insects, and therefore few other organisms have been exposed to it. The effect that the widespread release of the active toxin may have on non-target organisms has not been researched by the producers of Bt plants, but some of the available data is matter for concern.
Green lacewings are major predators of corn pests.
This means that Bt resistant insects could eat Bt corn, then fly away to other plants where they were in turn eaten by lacewings, which would then die. Potentially, the ecological disruptions extend far beyond the transgenic crop plots. The London Times reported that the lifespan of ladybugs was reduced to half when they ate aphids that had fed on genetically altered potatoes in fields in Scotland. The ladybugs also laid fewer eggs. It is not clear if the bee mortality was the result of Bt cotton since no further information has been made available.