A coalition of environmental groups, including Greenpeace, notified the U.S. EPA yesterday of intent to sue, contending that the agency could harm a number of endangered species such as the Karner blue butterfly if it renews licenses for genetically modified crops that are toxic to insects. A Cornell University study last year found that pollen from one type of genetically engineered corn can kill monarch butterfly larvae, and enviros fear that gene-altered crops could adversely affect other species as well. Meanwhile, U.S. government officials said yesterday that millions of bushels of StarLink corn, a genetically modified variety that has not been approved for human consumption, may have made their way into the food supply. A spokesperson for Aventis, the developer of the corn, said that conversations with farmers growing the corn have revealed that some did not know the corn was approved only for livestock feed or industrial use and some had forgotten the restrictions.