09/03/2026
New World Screwworm and the Border
The announcement last month of the Mexican border's planned reopening, after being closed since May 2025, seemed to shock producers, consumers, auction owners, and the markets. In truth, it shouldn't have come as a surprise. Furthermore, it does not serve our industry well to fear monger about it.
There is currently strong, sustained demand for beef in the United States, even as our calf crops and cowherds sit at historic lows. To help make up the difference, beef, whether on the hoof or on the hook, is imported into the U.S. Prior to the border closing in November 2024, U.S. imports of Mexican cattle had averaged 1.18 million head annually (Peel, 2026).
Looking back to January 2025, the border was briefly reopened for inspected cattle imports, but as the New World screwworm (NWS) drew closer, it was closed again by May. The primary goal of the closure was to slow or prevent the spread of NWS for as long as possible, though these policies came with significant economic costs.
Even so, NWS has been confirmed in the United States, along the south Texas border. While the goal remains the same, to slow the spread of NWS, it raises an important question for policymakers at APHIS and USDA: does keeping the border closed still provide enough benefit to justify it?
An argument can be made that Canada closed its borders to livestock originating from Texas… well, a few other states did also. It is largely symbolic. The border closure did delay the pest, but it could not keep it out entirely. We use Mexican beef to supplement our own industry, and without it, it has tightened supplies, and even increased feeder cattle prices (Sumner, Jones, et al., 2026).
The specific port that reopened, in Douglas, AZ, sits roughly 350 miles from the nearest active NWS case, a considerable distance from the currently infected zones.
Something to keep in mind also, in a Southern Ag Today article, OSU’s Dr. Schaefer wrote, “Biosecurity policies are rarely static. As conditions change, so should the economic questions used to evaluate them. The challenge is no longer asking “Did the border closure buy enough time?” It is asking “How much additional protection does the closure provide today and is that protection worth its continuing economic cost?”” (Schaefer and Smith, 2026).
Conditions have changed. The original goal, it seems, was to keep the pest out as long as possible while doing as little economic damage as possible. We can only hope this was the right call, but there's little value in stirring up unnecessary drama now. As producers, and more specifically, as price takers, we're on the front line of this industry. The cost of a screwworm infestation will be significant, but so is the cost reflected in grocery store prices.
References
Schaefer, K. Aleks, and Rylee Smith. “Reopening the Border to Mexican Cattle Imports is the Right Decision.” Southern Ag Today 6(31.4). July 30, 2026.
Sumner S., Jones S., Islam T., and Schaefer K.A. (2026) “Delaying the Inevitable? U.S. Screwworm Closures and Feeder Cattle Market Dynamics,” Applied Economic Perspectives and Policy, https://doi.org/10.1002/aepp.70111.
Peel, Derrell S. “Mexican Border Basics,” Cow-Calf Corner Newsletter. April 6, 2026
Article by Kallie Clifton, Area Agricultural Economics Specialist
Biosecurity trade restrictions are commonly framed as preventive measures, yet in many settings they function primarily as policies of delay: they impose immediate market costs while only postponing ...