How KALRO turned waterbuck scent into a shield against tsetse flies

A scent that helps waterbuck avoid tsetse flies could soon help protect livestock and people from the insects that transmit serious diseases.

Scientists at the Kenya Agricultural and Livestock Research Organisation (KALRO) have developed a natural repellent sachet that uses compounds tsetse flies naturally avoid, creating an odour barrier around its users.

The technology, known as Tsetse Fly Shield, is designed for livestock farmers, pastoralists, herders, wildlife rangers, researchers and other people who work or live in areas where tsetse flies occur.

“Tsetse Fly Shield is an eco-friendly natural repellent designed to protect livestock and people against tsetse fly bites. It is formulated using a proprietary natural blend of compounds that tsetse flies naturally avoid, creating a protective odour barrier that reduces biting pressure and the risk of disease transmission,” said Emily Kipsura, a research scientist.

The research draws from the natural relationship between waterbuck and tsetse flies. Scientists found that certain compounds associated with waterbuck odour can discourage tsetse flies from approaching.

Instead of killing the insects, the technology works by making livestock or people less attractive to them.

The livestock sachet can be placed in a neck collar or animal harness, allowing the repellent to remain close to the animal during grazing and herding.

For people, the sachet can be worn as a bracelet or placed inside a vehicle when travelling through areas where tsetse flies are present.

“It should be used whenever livestock or people are exposed to tsetse flies, particularly during grazing, herding animals, field research, wildlife patrols, farming activities and when travelling through tsetse-infested areas,” Kipsura explained.

The sachets are designed to provide continuous protection for up to 30 days before replacement.

Tsetse flies are not simply a nuisance. They transmit parasites that cause animal African trypanosomiasis, commonly known as nagana, in livestock and human African trypanosomiasis, or sleeping sickness, in people.

For livestock keepers, the disease can affect animal health and productivity, creating an additional burden in areas where tsetse flies are common.

The repellent is intended to reduce contact between the insects and their hosts. By lowering exposure to bites, researchers hope to reduce opportunities for disease transmission.

KALRO says the technology can be used around dairy farms, ranches, pastoral grazing areas, livestock markets and wildlife-livestock interface zones, as well as in communities affected by tsetse flies.

The approach could also offer an alternative to conventional methods that rely on insecticides or other measures to control tsetse populations.

Researchers are pursuing wider application of the technology as they seek ways of reducing the impact of tsetse flies on livestock and people.

The product, however, should not be presented as a treatment for trypanosomiasis. Its role is prevention by reducing exposure to the insects that transmit the disease.

The potential benefits extend beyond disease prevention. Reducing tsetse exposure could help protect livestock health and productivity, although claims about increased milk or meat production, reduced veterinary costs and higher farmer incomes would require evidence from field use.

The waterbuck-inspired technology therefore represents a different way of tackling an old problem: rather than chasing or killing the tsetse fly, scientists are using the scent of one of its natural neighbours to persuade it to stay away.