Mexico boosts sterile fly production to fight screwworm, but critics say strategy insufficient

Mexico is ramping up production of sterile screwworm flies to combat a resurgence of the devastating livestock pest, but critics argue the effort is too little, too late. The country needs an estimated 600 million sterile flies per week to contain the outbreak between Panama and the United States, six times current capacity Source: Infobae/EFE.

Plant capacity and criticism

President Claudia Sheinbaum inaugurated a new biofactory in Metapa, Chiapas, on June 27, with a capacity of 28 million flies per week, aiming for 100 million by year-end Source: La Jornada. However, a former animal health official called the strategy "tardía e insuficiente" (late and insufficient), noting that the old plant once produced 500 million flies daily Source: La Jornada. Sheinbaum defended the technology as proven and noted that Cofepris is analyzing a more efficient US-developed strain Source: Milenio.

US border closure and bilateral tensions

The US closed its border to Mexican cattle in November 2024 after the first case in Chiapas. Sheinbaum described the closure as a "decisión unilateral" that also hurts US ranchers who depend on Mexican livestock for fattening Source: Infobae. She expressed hope that the fly production would lead to reopening, but acknowledged the decision rests solely with Washington Source: Milenio. Meanwhile, illegal cattle trafficking across the southern border complicates control efforts Source: Infobae.

International collaboration

Mexico is coordinating with Panama and international bodies like FAO and IAEA to strengthen sterile insect technique capacity. Technical dialogue with USDA continues, and support programs for ranchers in Sonora, Coahuila, and Durango are underway Source: Milenio, La Jornada.