Flesh-eating screwworms head for American livestock

The New World screwworm, a flesh-eating parasite previously eradicated from the U.S., is spreading in Mexico and Central America, prompting federal and state measures to prevent its entry. A cattle import ban from Mexico and a $750 million sterile fly facility are part of efforts to mitigate risks to livestock and beef markets, which are already strained by high prices and reduced herd sizes.