A second case of the flesh-eating screwworm fly has been confirmed in Texas by the US Department of Agriculture (USDA), days after an initial case in a one-year-old calf set off an aggressive response to stop the spread of the parasite in the dominant cattle-producing state. Texas's governor, Greg Abbott, said on Friday that state officials were working with the federal government to slow the spread of the fly and the infestations caused by larvae that feed on the living flesh of warm-blooded animals and humans. Officials are dispersing millions of sterile screwworm flies in the vicinity of where the twin infections were found about five miles apart in Zavala county, south-west of San Antonio. Those sterile male flies would prevent wild female flies from reproducing.