Tsetse Fly Eradication Allows Sustainable Livestock Protection

A parallel socio-economic survey and cost-benefit analysis, carried out on 277 farms found that farms outside the tsetse-infested area produced 38 per cent more milk, 64 per cent more meat and sold 2.8 times more livestock than similar farms in the tsetse-infested area. In addition, while 34 per cent of the farmers in tsetse-free areas owned the more productive improved breeds, only 6 per cent in the tsetse-infested areas owned them.

The survey estimated that there were 90 000 resident cattle in the Niayes area. With the eradication of tsetse, it is projected that farmers will be able to replace their local breeds with exotic breeds at a rate of 2 to 10 per cent a year. As a result, farmers will increase their annual income by US $3.7 million because they will be able to reduce the cost of treating animals and also have more profit from selling milk and meat. Even though the cost of the programme is high with the need to train staff, establish infrastructure, and procure, sterilize, transport and release sterile flies, the cost-benefit analysis showed that by sustainably eliminating the vector, the programme will pay for itself in 13 to 18 years.

Based on results of the surveys, the Government of Senegal opted for an area-wide integrated pest management (AW-IPM) approach that included an SIT component. The project divided the target area into three ‘blocks’ and began activities in Block 1, using tsetse suppression methods, such as setting insecticide-impregnated traps and applying insecticide directly onto the animals. This reduced fly density to a fraction of what it had been, setting the scene for using the SIT as the final eradication component.

However, this required a great deal of preparatory activity before actually beginning the release of sterile males. Between 2008 and 2011 when suppression activities began, arrangements were made with a massrearing facility in Burkina Faso to produce and sterilize the appropriate strain of tsetse. A protocol was also established for transporting the sterilized pupae from Burkina Faso to Senegal, and a fly dispersal centre was established in Dakar to handle the received pupae. Trials were held to test how the sterile flies would perform in the target area, and the project developed and tested a new adult male release system that utilized a gyrocopter that enabled efficient aerial releases over the fragmented habitat.

Although, statistically, it is too soon to say if the tsetse population has been eradicated in Block 1, no wild flies have been seen in the traps set by the project since 2012. In Block 2, trap catches have been reduced by more than 90 per cent indicating excellent suppression. Progress is also evidenced in the drastic reduction in disease prevalence – from 45 to 50 per cent in 2009 to 10 to less than 10 per cent in 2014.

Building on the success in the Niayes area, the Government of Senegal is looking at the feasibility of expanding to other tsetse-infested areas in the eastern part of the country. The timing is especially important as the tsetse habitat is expanding. Senegal has also been using the Niayes programme as a training ground for tsetse staff from Senegal and other parts of Africa, and Burkina Faso has constructed a larger mass-rearing facility for tsetse mass rearing.