CHICAGO: The flesh-eating livestock pest New World screwworm has advanced closer to the US border with Mexico, the US Department of Agriculture said, prompting Washington to block imports of Mexican cattle just days after it allowed them to resume at a port of entry in Arizona. Screwworms are parasitic flies whose females lay eggs in wounds on warm-blooded animals, usually livestock and wild animals. Once the eggs hatch, hundreds of screwworm larvae use their sharp mouths to burrow through

Tag-uri: Agricultura