Chiapas Sterile Fly Plant Reopens to Combat Screwworm Infestation

A sterile fly production facility in Chiapas is being reopened and modernized as part of a joint U.S.-Mexico effort to combat a cattle screwworm outbreak that has disrupted cross-border livestock trade.

The United States has committed US$21 million to renovate the facility in Tuxtla Gutiérrez, according to Mexico’s Agriculture Minister Julio Berdegué. Once operational, the plant will produce approximately 100 million sterile flies weekly to supplement production from an existing facility in Panama that has been operating at maximum capacity.

Screwworm Fly Threat

The screwworm fly poses a serious threat to livestock by laying larvae in open wounds, creating potentially fatal infestations. The sterile insect technique works by releasing laboratory-bred sterile male flies into affected areas, disrupting the reproductive cycle when they mate with wild females.

This biological control method has a successful history in Mexico. The Chiapas plant originally opened in 1976 as part of a joint eradication program that by 2003 had eliminated screwworm throughout Mexico.

Economic Impact

The current outbreak has significantly impacted Mexico’s agricultural economy. Since May 11, the U.S. Department of Agriculture has suspended imports of live cattle, bison, and horses from Mexico due to the pest’s spread. According to Mexico’s National Agricultural Council, this suspension could cost Mexican producers approximately US$11.4 million daily.