Waterbuck perfumes can put off tsetse fly in cows

LIVESTOCK FARMING | TSETSE FLIES

As Uganda battles with the problem of tsetse flies attacking cattle, scientists have developed a perfume that can repel the blood sucking insects.

Tsetse flies cause a disease called nagana in livestock and sleeping sickness in humans. The disease is caused by a parasite that is transmitted when the tsetse flies bite animals and humans to feed on their blood. The pests are a nuisance in some parts of Uganda and Africa.

Nagana is a debilitating chronic condition in livestock that reduces fertility, weight gain, and impacts meat and milk production. It also makes livestock too weak to be used for ploughing or transport, which in turn affects crop production.

Scientists from Germany estimate that the damage in Africa caused by tsetse flies is estimated at about $4.6b annually.

Many people in tropical Africa are directly endangered, but the transfer to cattle also has drastic consequences for agriculture by reducing the production of milk, meat and labour.

In the fight against sleeping sickness, Prof. Dr. Christian Borgemeister of the Center for Development Research (ZEF) of the University of Bonn and a team of researchers from the International Center of Insect Physiology and Ecology (icipe), the Interafrican Bureau for Animal Resources (both in Kenya) and Rothamsted Research, Harpenden (Great Britain) pursued a new approach. The tsetse flies avoid waterbucks, an African antelope species, because they find the smell of the animals repellent.

The international team of scientists first isolated, identified and synthesized the waterbuck's repellents in the laboratory. They then filled tiny amounts of the tsetse fly-repellent substance into plastic containers that were tied to the cattle with a collar. They found that the waterbuck odour reduces disease rates by more than 80%.

This method was tested in a large two-year field trial in Kenya, where 120 Maasai herders provided over 1,100 cattle. Compared to unprotected cattle, the disease rates of the animals wearing the collar treated with the virus were reduced by over 80%.

The animals with the protective collar were healthier, heavier, gave more milk, plowed more land and achieved significantly higher sales on regional markets.

"This contributed to an improvement in food security and household income of the pastoralist families involved," Borgemeister said.

Compared to the animal medicines that are used to treat the disease, the collar method was cheaper and promising. The technology is very popular among the Maasai herders.

Officials from the ministry of agriculture said they would not consider the waterbuck perfume because it does not kill the tsetse flies.

Fredrick Luyimbazi, the commissioner of entomology at the agriculture ministry, said tsetse flies are a big problem in Uganda.

"In pest management, there is no technology that is satisfactory. You have to use an integrated approach. We are using traps and we plan to use nuclear technology to wipe out the flies," Luyimbazi said.

Help us
The Government recently asked the International Atomic Energy Agency (IAEA) to help Uganda get rid of the flies using the nuclear technology.

Energy minister Irene Muloni made the request to use the nuclear-based sterile insect technique (SIT) during a meeting with Ambassador Yukiya Amano the IAEA director general in Austria.

In Uganda, parts of Karamoja, West Nile Region and Murchison Falls National Park,  Lake Victoria basin, Busoga, Queen Elizabeth Park, Semliki National Park and Lake Mburo Park get the flies seasonally.

According to the IAEA, the sterile insect technique is an environmentally-friendly insect pest control method involving the mass-rearing and sterilisation, using radiation, of a target pest, followed by the systematic area-wide release of the sterile males by air over defined areas, where they mate with wild females resulting in no offspring and a declining pest population.

Jointly with the Food and Agriculture Organisation (FAO), the IAEA assists its member states in adopting nuclear-based technologies for optimising agricultural insect pest management practices that support the intensification of crop production and the preservation of natural resources.