Texas Officials Report First New World Screwworm Cases Since 1966

The New World screwworm fly was found in Texas last week for the first time since 1966, and officials reported the first case in neighboring New Mexico on Monday. The parasitic fly lays eggs in open wounds of livestock, pets, and sometimes humans. Larvae feed on living tissue and can kill an untreated host within a week.

Before eradication in the 1960s, the pest caused $10 million to $20 million in annual losses for livestock producers, according to USDA estimates. Texas accounts for about 14 percent of U.S. cattle production. If the fly reestablishes, Texas A&M estimates $2.1 billion in cattle losses and $9 billion in hunting and wildlife losses in Texas alone.

The USDA has directed millions of dollars toward producing and releasing sterile male screwworm flies to mate with wild females and produce infertile eggs. The agency converted a facility in Tampico, Mexico, last year with a $21 million investment and opened a $750 million factory and dispersal center in southern Texas earlier this year.

Texas agricultural commissioner Sid Miller stated the USDA moved too slowly and called the sterile insect method a partial solution. He urged use of bait and targeted pesticides and said current quarantine rules discourage reporting. Miller responded that the threat is too serious for name-calling and that his office will continue focusing on protecting Texas agriculture.

The USDA did not immediately respond to a request for comment.