How sterile insect technique can stop pest killing 3m livestock in Africa every year— FAO/IAEA

The tsetse fly kills more than three million livestock in sub-Saharan Africa every year and costs the agriculture industry more than $4 billion annually.

It transmits the parasites that cause nagana, a wasting disease that can devastate cattle herds. For a cattle farmer, this biggest threat to a herd may be something barely noticeable. A new Sterile Insect Technique could provide a solution.

As the Head of the Insect Pest Control Laboratory at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture Marc Vreysen explained, the high incidence of livestock infertility and weight loss, due to nagana, resulted in reduced meat and milk production, and cattle that were too frail to plough the land or transport produce, which in turn severely affected crop production.

The disease behind much of this damage is animal African trypanosomiasis, commonly known as nagana. Yet despite its economic impact, the problem can remain almost invisible at community level.

In Nigeria, where livestock is central to rural livelihoods and food security, researchers are exploring whether a technology that uses radiation in an unexpectedly precise way could help change that.

The approach is called the Sterile Insect Technique, or SIT. Its principle is simple: scientists rear large numbers of male insects, sterilise them using irradiation and release them into the wild. The sterile males continue to compete for mates, but the resulting eggs do not produce offspring. Repeated releases gradually reduce the population, generation by generation.

Nigeria has a long history of research into trypanosomiasis. The country has worked on the problem since 1947 and has had a dedicated research institution, the Nigerian Institute for Trypanosomiasis Research (NITR), since 1964. Nigeria has also participated in the Pan-African Tsetse and Trypanosomiasis Eradication Campaign, or PATTEC, launched in 2001. But decades of research do not automatically translate into awareness among the communities most affected.

A recent PATTEC-Nigeria baseline assessment in Gombe State illustrates the gap. More than 95 per cent of respondents reported experiencing tsetse bites, while awareness of PATTEC or NITR was below 5 per cent. Nearly 88 per cent of households surveyed said they spent more than ₦50,000 a month treating livestock.

The findings suggest that the challenge is ensuring that farmers recognise the problem and have access to effective solutions.
SIT is not a theoretical solution. Africa already has examples of what can happen when the nuclear technology is combined with conventional pest control and applied across an entire target area. On Unguja Island in Zanzibar, tsetse flies have been absent for more than 20 years.

The campaign first reduced the population through conventional measures before regular releases of sterile males helped eliminate the remaining flies.

The disappearance of the vector was followed by a decline in nagana and improvements in livestock production. Senegal provides another example. In the Niayes region, an eight-year programme reduced the tsetse population by more than 98 per cent. Researchers also found that the impact on other monitored insects was minimal and temporary. As an entomologist of Senegal’s ISRA Mireille Bassin put it, the scale of the reduction was highly encouraging.

The broader lesson is that SIT is designed for precision. It does not require the indiscriminate killing of insects across an ecosystem. Instead, it targets a particular species by exploiting its own reproductive biology. Former Head of the IAEA’s Africa Division Ali Boussaha has noted, “When the SIT programme is well applied it leads to total eradication. This is the only wayyou can eradicate the tsetse fly.”

This principle is being explored beyond the fight against the tsetse fly. For example, Rosatom is developing applications of nuclear technologies, including in agriculture. In particular, the Nuclear Research and Technology Centre in El Alto, Bolivia, is designed as a multifunctional platform combining medical, research and applied tasks. In 2024, mosquitoes carrying yellow fever were irradiated here for the first time.

Sterile male mosquitoes are intended to reduce the population of disease vectors without the additional use of chemical control methods. This example demonstrates how irradiation technology can find applications far beyond its more familiar fields of nuclear energy and medicine.

For Nigeria, the foundations for such work already partly exist. International coordination and expertise are available through the Joint FAO/IAEA Centre in Seibersdorf, while African institutions contribute experience in insect rearing, field releases and veterinary research. NITR also has links with regional organisations working on tsetse and trypanosomiasis.

Nigeria possesses relevant infrastructure as well. A large gamma irradiation facility operates at the Sheda Science and Technology Complex under the Nigeria Atomic Energy Commission.

According to the Nigerian Nuclear Regulatory Authority, the facility has applications that include research into the Sterile Insect Technique for controlling agricultural pests and insects affecting animal production.
This does not mean Nigeria is ready to launch a nationwide eradication campaign tomorrow.

SIT requires detailed mapping of insect populations, reliable mass-rearing facilities, trained specialists, continuous monitoring and strong participation from local communities. Most importantly, releases have to cover an entire target area: isolated surviving populations can allow the pest to return.

Nigeria’s advantage is that many of the building blocks are already there: almost eight decades of research, a specialist institute, international partnerships and nuclear infrastructure that can support agricultural applications. The remaining challenge is awareness.

For farmers facing sick cattle, sterilisedflies may sound abstract, but the benefits – healthier herds, higher milk and meat yields, and stronger draft animals – are concrete. Nigeria has studied the problem for decades. The next step is turning that knowledge into a large-scale solution that protects livestock and livelihoods.