U.S. and Mexico Fight Over Screwworm

Mexico might find itself screwed out of animal exports if it doesn’t let the U.S. step in to help eradicate the New World Screwworm outbreak.

According to Ag Secretary Brook Rollins’ letter to her Mexican counterpart, Mexico has been limiting companies hired for aerial spraying to eliminate the pests. They were only flying six days a week and put “burdensome custom duties” on parts needed for these planes. Her full letter can be found on X.

Zoom out: Screwworms are nothing to screw with. They can infest livestock, wildlife populations, and even people. Their maggots burrow into the skin of living animals and can cause terrible—and many times fatal—damage.

Timeline: Rollins said if Mexico does not act by Wednesday, April 30, the USDA will restrict live cattle, bison, and equine imports from Mexico.

And this: The U.S. is asking the Mexican government to give Dynamic Aviation operational clearance for a year at minimum, but hopefully indefinitely. It’s also asking for tariff waivers for aircraft parts, flies, and equipment from APHIS, as well as the appointment of a Mexican point of contact to handle these issues.

Trust the science: The U.S. and Mexico have been working on a way to delete screwworms from existence by releasing sterile male flies to breed with the wild screwworm.

Rewind: The U.S. originally blocked cattle and bison imports in November when the parasite was found in southern Mexico. This tightened U.S. cattle supplies and led to higher cattle and beef prices. Imports picked up in February with a new rule that animals have to be inspected for screwworm before and after arrival in the states.

Prior to the screwworm, Mexico was the U.S.’s biggest cattle supplier. A month ago, the U.S. imported 24K head from Mexico. A year ago, this number was 114K.