The U.S. Department of Agriculture (USDA) announced Monday that two additional cases of New World screwworm have been confirmed in Texas, bringing the state’s total to four. The infestation, which involves fly larvae that consume the living flesh of warm-blooded animals, has triggered concerns regarding the potential impact on the nation’s cattle industry. Officials confirmed the latest cases involved a calf in La Salle County and a dog in Andrews County.
How the parasite is affecting Texas and the cattle industry
The New World screwworm was eliminated in the United States in the 1960s, but it was detected again in Mexico in late 2024. While the parasite poses a threat to cattle, the USDA notes it does not infest meat or fruit. According to the USDA, beef prices currently remain near record levels due to a reduced number of cows in the U.S., rather than the current infestation. In response to the recent findings, Canada temporarily halted imports of livestock, including cattle and horses, from Texas as of Friday. The larvae thrive in humid conditions where temperatures reach at least 77 F (25 C), making the pest a particular concern during warmer months.
Why officials disagree on the eradication strategy
Federal officials and state leadership are at odds over the best path to eliminate the pest. The USDA is working to increase sterile fly production in foreign plants and is constructing a massive fly-rearing facility in Texas. The goal is to release sterile males to mate with wild females, eventually halting the population. University of Florida entomologist Edward Burgess noted that this long-term solution is still months away. Conversely, Texas Agriculture Commissioner Sid Miller has pushed for the use of a poison bait, arguing that the federal plan takes too long and could cripple the cattle industry. Miller criticized the USDA for not closing the U.S.-Mexico border to pets, citing the infected dog’s recent travel history. Federal experts have countered that the proposed bait is unproven and poses a risk to other insects, animals, and humans.
What experts expect in the coming weeks
While the confirmed cases are hundreds of miles apart, scientists do not necessarily view the situation as a rapid spread. Edward Burgess explained that increased vigilance and focus on the issue naturally lead to more frequent detection of the larvae. Experts expect a small number of additional cases to be identified in the near future as officials continue sampling suspected cases. USDA Secretary Brooke Rollins is scheduled to hold a news conference on Monday afternoon following a briefing at the U.S. Livestock Insects Research Laboratory in Kerrville, Texas, to discuss the ongoing response.