Episode 266: Need to Know: New World Screwworm

The New World Screwworm has been uncommon in the U.S. since the 1960s, but plenty of ranchers, especially those in the Southwest, still remember how devastating a problem it can be. 

The larval maggots of the screwworm feed exclusively on living flesh, and an infested animal can succumb in a matter of days. So evidence that the pest is moving Northward from Southern Mexico is a key concern for American ranchers.

DTN Senior Livestock Editor Jennifer Carrico has been following the unfolding story of the New World Screwworm for months now, and joins us this week to bring us up-to-date on the very latest news from both sides of the border. She’ll walk us through a timeline of detections from the last several months, including insight she’s learned from Texan and Mexican cattlemen as they deal with the fallout of lengthy inspections and closed borders. Then she’ll help us understand the potential impact of the pest, including how it affects cattle, how USDA and others are monitoring its progress, and how concerns about spread might be impacted by weather conditions. 

Finally, we’ll talk about how this new threat is weighing on producer decision-making for the 2026 season, and hear how industry and trade groups are encouraging ranchers to prepare for what might be ahead.