Does Bt Corn Reduce Insecticide Use? 

Bt. corn is one of the only Bt. crops that does not reduce the application of insecticides. In 1995 (before Bt. corn was released) 6.75% of all US corn acreage was treated for European Corn Borer infestation; in 2000 7.3% of the total acreage was treated (Benbrook). Some experts point to rising corn prices as a reason that more acreage is being better tended to. It is important to remember that other Bt. crops especially cotton reduce insecticide application and typically a safer insecticide is used.

Impact on Non-Target Species 

Prior to being released in the US The Environmental Protection Agency conducted extensive research on Bt. corn. It was found that non-target species are in no way affected by the toxin. This is because," the mechanism whereby Bt protein controls the corn borer is highly specific, and most non-target organisms are not affected by it, since they digest the protein along with all others in their diet" (Syngenta). 

1999 Butterfly Scare 

In 1999 Cornell University published a study that claimed pollen from Bt. corn was detrimental to Monarch butterfly caterpillars. This lead to further investigation by the EPA. The EPA discovered that the dosages used in the study were much higher than any caterpillar would ever ingest, thus discrediting the study (Syngenta).  Independent studies have confirmed these results with Black SwallowtaIl larvae as well.

"Although many of the larvae died... there was no relationship between mortality and proximity to the field or pollen deposition on host plants. Moreover, pollen from these same plants failed to cause mortality in the laboratory at the highest pollen dose tested (10,000 grains/cm²), a level that far exceeded the highest pollen density observed in the field (200 grains/cm²). We conclude that Bt pollen of the variety tested is unlikely to affect wild populations of black swallowtails", (Wraight).

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