The U.S. Department of Agriculture says the United States' food supply is not at risk after confirming two more cases of the New World screwworm.

As New World screwworm enters the U.S. for the first time in decades, we should be vigilant but not panic, experts told USA TODAY.

US farmers and officials are worried about the arrival of screwworm in Texas after a calf was found with the flesh-eating parasite.