Sort and Cull

REDFIELD, Iowa (DTN) -- New World screwworm (NWS) has caused the U.S./Mexico border to be closed and opened and reclosed several times during the past year as the pest moves north in Mexico. The closure is to help prevent the insect from traveling into the U.S. on a beef animal destined for a feedlot.

Last week, U.S. Secretary of Agriculture Brooke Rollins announced the federal government committed $850 million toward the fight against NWS, with $750 million of that going toward the building of a sterile fly production facility in southern Texas. (See https://www.dtnpf.com/….)

While the sterile insect technique (SIT) isn't new, in this case, there's only one facility in the world producing the sterile NWS flies -- in Panama. The Panama site produces 115 million sterile flies per week, and the new Texas facility will produce 300 million per week once completed in early 2026.

HISTORY OF U.S. OUTBREAKS

The NWS dates to at least 1842, according to USDA APHIS Veterinary Services. The early losses in the 1940s were estimated at $5 million to $10 million annually nationwide. The federal government started investing in programs for NWS prevention and education in 1935. By the 1950s, the SIT was commonly used. Producers in the U.S. Southeast had losses of up to $10 million to $20 million per year prior to NWS eradication in 1959. The Southwestern states had losses between $50 million to $100 million each year, which was because of higher livestock populations in those areas. Eradication was finally successful in the rest of the U.S. in 1966 and ultimately cost $32 million to complete by putting a screwworm barrier zone along the U.S./Mexico border.

More localized outbreaks continued to happen in the U.S. Southwest throughout the 1970s since NWS was still present in Mexico. The economic impact of the outbreak in Texas in 1976 was $132.1 million to manage and a total impact of $283 million to $375 million on the Texas economy. It was estimated that the 1976 outbreak infested 1,488,256 cattle and 332,600 sheep and goats. Pushing the NWS farther south in Mexico was a challenge but was achieved by 1986.

MORE RECENT OUTBREAKS

In 2016, NWS was discovered in Key deer in the Florida Keys. Sterile flies were released as soon as it was discovered to help control the outbreak, and NWS was again eradicated in early 2017 without affecting the livestock industry.

The USDA study adjusted estimated costs on the Texas industry for inflation to 2016 and 2024 costs. In 2016, the cost per case for cattle would have been $346.28, and that increased to $452.14 for 2024. Overall, the losses to livestock producers due to the NWS outbreak in Texas in 2016 were estimated at $561.1 million and an overall economic loss of $1.4 billion.

The adjustments for 2024 showed a loss to Texas producers of $732.6 million and a total economic loss of $1.8 billion. Texas remains the No. 1 cattle state in the country, being home to cow-calf producers and feedlots. Clearly, the amount would be a lot more with other states involved.

In the end, it makes the $850 million investment announced by Rollins last week look like a great decision in my eyes. The beef cow herd is the lowest it has been in decades, and cattle on feed inventories are not increasing either. (See https://www.dtnpf.com/….) A potential infestation of NWS could have a devastating loss to the livestock economy and the overall economy of the U.S., while affecting our food supply. Keeping it out is a priority. Thank goodness those at USDA see the importance of that as well.

Jennifer Carrico can be reached at jennifer.carrico@dtn.com

Follow her on social platform X @JennCattleGal

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