Jared Laureles
Sent
La Jornada Newspaper
Sunday, October 19, 2025, p. 5
Metapa De Domínguez, Chis., With a production of 700 million sterile flies each week, Mexico has remained free of the Mediterranean fly for more than 40 years, which has allowed Mexican farmers to export their fruit and horticultural products to other countries, with a commercial value that amounts to 13 billion dollars, according to official data.
Through the Moscamed program, in which Mexico, the United States and Guatemala participate, the containment of this pest, one of the most harmful in the world, has been achieved, since it attacks more than 250 fruits and vegetables such as coffee, mango, guava, sweet citrus fruits, peach, apple, tomato and pumpkin, said Salvador Meza, fly production coordinator of the National Health, Safety and Health Service. Agri-food Quality (Senasica).
He highlighted that since 1982 the country has been free of the quarantine plague; However, due to its presence in Central and South America, the area bordering Guatemala is under intense surveillance. “All our production is focused on putting up a biological barrier so that insects cannot enter the country; Guatemala has the active pest… and if we have the fly present in the country, then they (production) cannot move, billions would be lost,” he warned.
In the Moscamed program, which has operated since 1977, more than one billion pesos are currently invested annually, but its benefits are of high economic importance by protecting the country’s national fruit and vegetable market, according to the Ministry of Agriculture and Rural Development.
This newspaper visited the new breeding and sterilization plant for male Mediterranean flies, which has technologies and has been operating since August 2021; It is located in Metapa de Domínguez, a municipality of Chiapas located in the Soconusco region and key in the production of bananas and coffee.
In this laboratory, sterilized insects are produced in a self-sufficient manner, contemplating all their phases: sowing and collecting the eggs; the growth of larvae, the maturation of pupae and their reproduction into an adult fly.
Meza explained that 10 to 12 liters of eggs are collected daily, which contain 600 million eggs and from which the larvae will emerge; These are subjected to a diet based on yeast, sugar and wheat bran, which are nutrients contained in a cellulose base so that they can grow healthily and be able to compete in the field.
Same technique as with the screwworm
To eradicate the Mediterranean fly, known as the fruit fly, the sterile insect technique has been key and is the same one used to combat the cattle screwworm (GBG).
The principle consists of releasing male insects sterilized with Gamma rays, so that in the field they mate with wild females that will no longer be able to lay fertile eggs and prevent the reproduction of the pest, he explained.
Another of the plants involved in the strategy is the packaging plant and is located in Tapachula. In this place the pupae are conditioned so that the adults are born, in addition to receiving the sterilized Mediterranean flies from the new facilities in Metapa de Domínguez.
Once packaged, and prior to release, the insects spend around 45 minutes in cold rooms at zero degrees to “put them to sleep,” said Iris Carreón, head of the operations center.
Currently, between 100 and 120 million sterile flies are dispersed daily by air, through “releasing boxes” in different regions of Chiapas.
Since the late 70s, the first Mediterranean fly sterilization plant was built; It had been in operation for 40 years and due to its limited production capacity since it depended on the importation of eggs from the “El Pino” plant in Guatemala, it was replaced by the facilities inaugurated in 2021.
However, this old property, also located in Metapa, 18 kilometers from the border with Guatemala, will house the new production plant for sterile screwworm flies to also eradicate this pest, as happened more than three decades ago.
