A flesh-eating parasitic fly has returned to the United States after 60 years. The US Department of Agriculture confirmed the presence of New World screwworm in a calf in southern Texas this week.
The New World screwworm poses a major threat to livestock. Releasing sterilized flies can crash a local population of the insects. The US currently has limited capacity to produce the sterilized flies needed for such efforts. The USDA is evaluating options to expand production. The confirmation marks the first detection in the country since the 1960s.