The biggest outcry is in Europe, where protesters who want to halt U.S. imports dumped genetically altered seeds on government officials' doorsteps. Researchers from Cornell University reported that BT corn pollen can kill not just pets but also the larvae of Monarch butterflies. John Losey was the lead author for the study. Forty-four percent or almost half of the caterpillars feeding on the BT pollen treatment were dead. And those that weren't dead were significantly smaller.
Monarch caterpillars feed exclusively on milkweed.
This is milkweed with the pink flowers. And, if you notice, if you break off a leaf or a stem, it produces a latex sort of substance, and it looks like milk. Losey says the risk to the butterflies is significant, because they breed mostly in U.S. corn belt states. But the industry says Losey's laboratory study doesn't reflect real life. Val Giddings is a vice president of BIO, the Biotechnology Industry Organization.