Mexico manages to eradicate the fruit fly with a nuclear technique

An alliance between Mexico, the International Atomic Energy Agency and the Food and Agriculture Organization of the United Nations has managed to eradicate the Mediterranean fly in the Mexican state of Colima. The insect can cause devastating damage to fruits and vegetables.

The outbreak was detected in April 2021 in the country’s largest port, Manzanillo, and posed an immediate risk to a number of crops such as star fruit, figs, guavas, mangoes, papayas, pink grapefruit, and oranges.

If this action had not been managed promptly, Mexico, the seventh largest producer and exporter of fresh fruits and vegetables in the world, could have suffered the imposition of quarantines by countries that do not suffer from this plague.

The trade of this type of product generates more than 189,000 million Mexican pesos (more than 9 billion dollars) annually in exports, as well as millions of local jobs.

“If the Mediterranean fly had settled in the country, the consequence would have been the closure of access to national and international markets for Mexican fruits and vegetables, which would ultimately have meant economic losses for local producers,” explained Francisco Ramírez and Ramírez, General Director of Plant Health of the National Service of Agrifood Health, Safety and Quality of Mexico

How was extinction achieved?

To control the outbreak, Mexico designed and activated an emergency plan with the help of experts from the International Atomic Energy Agency and the United Nations Organization for Agriculture.

Eradication was achieved by calling sterile insect technique, an environmentally friendly pest control system.

Medfly females can damage crops if they lay their eggs on mature crops, affecting their quality, making them unsaleable and inedible.

The project consisted of the breeding, sterilization and subsequent release of more than 1.45 billion male flies. Once free, these insects mate with wild females that do not produce offspring, leading to a decline in the pest population and eventually eradication.

The facility where the sterilization took place, located in the state of Chiapas, is the second largest in the world with a production capacity of 1 billion sterile male flies each week.

One of the best methods

The sterile insect technique is one of the most environmentally friendly insect pest control methods devised to date.

Irradiation, for example with gamma rays and X-rays, is used to sterilize mass-reared insects so that, although they remain sexually competitive, they cannot reproduce. A good aspect is that it does not involve transgenic processes (genetic engineering).

The International Plant Protection Convention classifies sterile insects as beneficial organisms. The technique differs from traditional biological control, which involves the introduction of non-indigenous biological control agents, in several aspects:

• Sterile insects do not self-replicate and therefore cannot establish themselves in the environment
• Breaks the reproductive cycle of a pest, which is also known as autocidal fight, is by definition something specific to each species
• Does not introduce non-native species into an ecosystem

Together with the FAO, the IAEA helps Member States develop and adopt nuclear-based technologies to optimize agricultural insect pest management practices that support the intensification of crop production and the preservation of natural resources.

Benefits of the technique

The sterile insect technique was developed in the United States and has been used successfully for more than 60 years. Currently applied on six continents.

The four strategic options in which sterile insects are released as part of zonal integrated pest management are: suppression, eradication, containment and prevention.

For more than five decades this technique has been one of the fundamental actions of the joint program between the FAO and the IAEA in the elimination of pests.

This action encompasses applied research work to improve the technique and perfect it in order to combat new pest-causing insects, and the transfer of knowledge to Member States through field projects, so that they can benefit from plant health, improved animal and human lives, a cleaner environment, increased crop and livestock production in farming systems, and faster economic development.