Recent attempts of growing it in Mexico are bumping into quite a bit of red tape.
Bt Corn is also called Transgenic maize corn and is a GM (genetically modified) crop. Bt corn thanks its name to the gene inserted into its DNA that codes for the Bacillus thuringiensis (Bt) toxin which protects the corn from insects. The gene was isolated from the Bacillus thuringiensis, which is a microorganism found in soil.
Bt corn is also resistant to herbicides, which makes it possible to use herbicides without damaging or killing the crop itself. Insecticides are no longer necessary with Bt corn, because the introduction of the Bt gene protects it from pests. The pest that usually affects corn production is the European Corn Borer. The Bt toxin crystallizes the digestive tract of the insect larvae, which leads to their death.
Although there were some concerns of Bt corn pollen producing a threat to the monarch butterflies, studies later showed this was not the case.
There is one problem with attacking pests “naturally” with the Bt toxin is that the pests themselves can become resistant to the Bt toxin. To solve this, farmers who grow Bt corn are by law required to also plant regular corn close by. The regular corn is supposed to harbor pests so it is less likely that natural selection will help develop a Bt resistant population. There are some concerns with cross pollination, but because pollen are wind born planting a larger field of non Bt corn can solve the issue.