More Dangers of Genetically Altered Plants.

• Author: Aplyn, Eric
• Position: Brief Article

A Dead Good Bug: GE's Impact on Beneficial Insects

Organic farmers have used the Bacillus thuringiensis (Bt) bacteria for years to control certain pests. Socalled life sciences companies toot their horns over their successes in incorporating parts of Bt's genetic code directly into the genetic code of certain commodity crops, thereby, they claim, protecting corn, cotton and potatoes from predators. 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 Et plants, but some of the available data is matter for concern.

For example, springtails (Collembola) are flightless insects that feed on fungi and debris in soil and are active decomposers-an essential step in the cycles of the plant ecosystem. A study submitted to the US Environmental Protection Agency indicates that Novartis's Bt corn harmed springtails (EPA MRID No. 434635). Green lacewings are major predators of corn pests. Researchers from the Swiss Federal Research Station for Agroecology and Agriculture found a two-thirds increase in mortality of green lacewing larvae that were fed either European corn borer or armyworm larvae raised on Novartis' Bt corn, as compared to lacewing larvae fed larva raised on non-transgenic corn (I-lillbeck et al., 1998). Ominously enough, it did not matter if the lacewings ate prey that had been poisoned by Bt or prey that proved to be Bt resistant. 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 disrup tions 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.

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