On the Screwworm Line: Ranchers Across the Border, One Crisis

The screwworm crisis is crushing ranches from both sides of the US-Mexico border—and it’s throwing a wrench into what little economic stability cattle producers have left.

A Texas rancher and a Mexican producer are sharing boots-on-the-ground perspectives on how the New World screwworm has reshaped their operations. For cattle ranchers already squeezed by debt, volatile commodity prices, and input costs, the screwworm adds another layer of operational hemorrhaging: treatment costs, herd losses, extra labor for monitoring, and the gnawing uncertainty of whether an animal can be saved once infected.

The screwworm, a parasitic larva that burrows into living tissue and can kill an animal within days, isn’t new. But its return to the US after decades of suppression marks a shift in the risk calculus for ranchers who’d built contingencies around its absence. For producers operating on razor-thin margins, the ripple effects compound fast. A single infected calf can cost hundreds in treatment and productivity loss. A herd outbreak becomes catastrophic.

Cross-border cooperation matters here, because the pest doesn’t respect fences. Ranchers in Mexico and Texas face a shared threat and, increasingly, a need to share data and prevention strategies. The screwworm returns: another cost shock for squeezed cattle ranchers piece laid out the scale; what ranchers are saying now is that this crisis is eroding the already-fragile foundation many built their operations on.

For ranch economies already crushed by debt spirals, the screwworm is another reminder that climate, pests, and disease don’t wait for farmers to get their balance sheets in order. And when ranchers can’t absorb shocks, consolidation often follows.