Mexico, US, and Panama Advance Screwworm Control Plant

Mexico, Panama, and the United States are strengthening efforts to contain the New World screwworm through a sterile fly production facility in Chiapas that is expected to produce 100 million sterile insects per week, as authorities seek to protect livestock production and animal health across the region.

Columba Jazmín López, Mexico’s Minister of Agriculture and Rural Development (SADER), visited the sterile fly production plant in Pacora, Panama, on Thursday to coordinate the launch of Mexico’s new facility in Metapa de Domínguez, Chiapas, which is scheduled to begin operations on June 25.

The Metapa biofactory has reached 87% completion and is expected to gradually scale up production to 100 million sterile flies per week. The facility forms part of Mexico’s strategy to control and eradicate the New World screwworm, a transboundary livestock pest that affects cattle and other animals.

According to SADER, cooperation with Panama has been essential to the development of the Mexican facility. Through the Panama-United States Commission for the Eradication and Prevention of Screwworm (COPEG), Panamanian specialists have provided technical assistance on mass sterile fly production, insect irradiation, biosafety protocols and personnel training.

Currently, 11 Mexican technicians are receiving training through COPEG in Panama. Seven of them are expected to complete their training this week and will begin operating the Metapa facility when it opens later this month.

As part of the regional effort, Mexico and the United States have jointly contributed US$61.3 million to adapt and operate the plant. The Animal and Plant Health Inspection Service (APHIS) of the US Department of Agriculture allocated US$22.9 million for infrastructure rehabilitation and an additional US$8.4 million to support operations during the second half of 2026.

The project has gained additional urgency following the recent confirmation of the first New World screwworm case in Texas since 1966. The US Department of Agriculture (USDA) detected the parasite in a three-week-old calf in Zavala County, near the Mexican border, prompting containment measures and renewed concerns over the potential impact on the North American livestock industry. The case marked the first confirmed detection of the pest in the United States in six decades and underscored the need for coordinated regional surveillance and sterile fly production capacity.

“The New World screwworm does not recognize borders. Mexico is convinced that cooperation with Panama and the United States, through COPEG, is essential to protect animal health, livestock production, the economy of ranching families and the sanitary security of our region,”  López said during the visit. 

The minister said the Mexican government, under President Claudia Sheinbaum, remains committed to regional cooperation, solidarity and rapid action to address the livestock health challenge alongside Panama’s Ministry of Agricultural Development (MIDA), USDA-APHIS and Mexico’s National Service for Agrifood Health, Safety and Quality (SENASICA).

Roberto Linares, Panama’s Minister of Agricultural Development, said both countries face common challenges in the agricultural sector and reiterated Panama’s willingness to support Mexico through COPEG, particularly in sterile fly production processes.

The launch of the Metapa facility is expected to strengthen regional surveillance and containment efforts against the New World screwworm while expanding sterile insect production capacity in North and Central America.