**New World screwworm (Cochliomyia hominivorax) myiasis in livestock is driven by larval infestation of wounds, with females laying eggs that hatch into flesh-eating maggots; the U.S. has maintained eradication since the 1960s via sterile insect technique (SIT) releases along the southern border.** The June 2026 index case in a Zavala County, Texas calf triggered an APHIS/TAHC response with additional confirmations in La Salle, Gillespie, and other Texas counties through early summer, plus one non-livestock detection in a New Mexico dog near the border. As of mid-August 2026, active cases remain concentrated in Texas livestock with no verified spread to other states in cattle, goats, or sheep per USDA dashboards. Key controls include expanded SIT dispersal, wound treatment protocols, movement restrictions, and port monitoring (e.g., Douglas, AZ reopening August 24 with the nearest active case ~325 miles away). Trader sentiment hinges on containment success versus northward or interstate livestock/wildlife movement during peak fly activity. Upcoming APHIS surveillance updates, any new county-level confirmations, and model runs on fly dispersal or import risk will be primary near-term catalysts. Historical precedent shows rapid SIT response can limit outbreaks, but border proximity sustains reintroduction pressure.