Bt corn pollen can hurt monarchs

Pollen wafts from a field of corn genetically engineered to make its own insecticide in amounts sufficient to kill monarch butterfly caterpillars nearby, according to an Iowa study.

The corn variety examined carries a gene from Bacillus thuringiensis for an especially strong punch of the bacterial toxin. The corn sheds pollen at worrisome concentrations up to 10 meters from the field, report Laura C.