A campaign against the tsetse fly, a pest that transmits a disease that devastates livestock, in the Niayes area near the capital Dakar has radically reduced the fly population and is paving the way for complete eradication.

“Since the project started, there is already less disease. It has not only reduced the tsetse but also ticks, which cause lots of other diseases in the area. We have noticed over all better health of the herds,” said Baba Sall, project manager and Head of the Animal Health Section in the Ministry of Livestock.

A multiyear programme of the Government of Senegal, with financial help from the United States and technical support from the Centre de Coopération Internationale en Recherche Agronomique pour le Développement (CIRAD), France, is slowly eradicating the tsetse fly using a method called the Sterile Insect Technique. The programme is supported by FAO through its joint division with the International Atomic Energy Agency in Vienna.

The Niayes area has a coastal micro-climate suitable for exotic breeds of cattle, the kind that produces more milk and meat than domestic stock.

Unfortunately, the area is also home to the tsetse fly, which transmits trypanosomosis. Often lethal, the disease reduces fertility, weight gain, meat and milk production and makes the cattle too weak to be used for ploughing or transport.

A government study estimates that when the tsetse fly is completely eradicated in the Niayes farmers will earn €1.2 million ($1.6 million) more per year because they will spend less on treating animals and earn more profit from selling milk and meat.

The government has an ambitious plan to introduce exotic livestock breeds and create a modern meat and dairy sector in the area, which is near the capital Dakar.

In-depth look at the campaign

The Sterile Insect Technique is a form of pest control that uses radiation to sterilize male flies that are mass-produced in special rearing facilities. The sterile males are released systematically by air on a sustained and area-wide basis over tsetse-infested areas, where they mate with wild females. These do not produce offspring and, as a result, this technique can eventually eradicate populations of wild flies.

Before the SIT can be used, the wild fly population needs to be suppressed to very low levels using other control methods. In the Senegal project area, this was achieved through applying pesticide directly to livestock, the use of fly traps and netted fences around pig pens.

Ground release of sterile males flies started in 2012 and air release in 2013 after three years of feasibility assessments, capacity building, preparation and testing.

After six months, the fly population was suppressed by more than 99 percent.

A further advantage of the technique is the fact that – after an initial phase of insecticide-based suppression – it does not require the use of pesticides and reduces environmental contamination.

“We expect to announce the tsetse fly eradicated in the first block in mid 2014. We have not captured any wild flies in our traps since March 2012 so they are almost finished there,” said Sall.

“After that we are going to attack blocks number 2 and 3 where we expect to achieve eradication in 2015 or early 2016. Two other zones will come next to continue the work we have started to eradicate the tsetse fly and trypanosomosis in Senegal,” he said.

Projects active worldwide

The Joint FAO/IAEA division supports about 35 sterile insect technique field projects delivered through the IAEA technical cooperation programme like the one in Senegal, in different parts of Africa, Asia, Europe and Latin America. It has already successfully eradicated the tsetse fly from the island of Zanzibar and the Southern Tsetse Eradication Project (STEP) in Ethiopia has reduced fly populations by 90 per cent.

Major insect pests such as fruit flies, moths, screwworm flies and mosquitoes are also targeted in addition to the different species of tsetse flies.

Jorge Hendrichs, chief of the FAO/IAEA SIT programme, says his team at the Insect Pest Control Labotarory at the FAO/IAEA Agriculture and Biotechnology Laboratories in Seibersdorf, Austria, offers a full service of applied research, training, field validation and operations and laboratory backup, with activities reinforcing each other in a type of “feedback loop.”

“For example, for the Senegal operation the sterile flies are mass-produced at the facility of the Centre International de Recherche-Développement sur l’Élevage en zone Subhumide (CIRDES) in Burkina Faso and shipped to Senegal”, he said. “At first the flies arrived in bad condition. We had to improve quality control, make adjustments to shipment and logistics, establish back-up colonies of the fly and so on. Once we had it working properly, we fed that experience back into our overall programme and we can use the lessons learned elsewhere.”

In all, around 37 African countries are affected by the tsetse fly and trypanosomosis kills around 3 million livestock per year. The FAO/IAEA SIT programme supports 14 African nations in their efforts to eradicate the tsetse fly.