Bt corn variety OK for black swallowtails

The first published field study of Bt corn and butterflies—and the first check for any Bt-pollen risks to black swallowtails—finds no harm from a common corn variety, say researchers of the University of Illinois at Urbana-Champaign.

Bt corn makes its own pesticide, thanks to genetic material borrowed from the soil bacterium Bacillus thuringiensis.