Extracts of Calpurnia aurea leaves from southern Ethiopia attract and immobilise or kill ticks

Calpurnia aurea extracts are used in southern Ethiopia to protect stock against ticks. Acetone, hexane and water leaf extracts of C. aurea collected in southern Ethiopia were tested for repellent/attractant and acaricidal properties on unfed adult Rhipicephalus pulchellus ticks. In contrast to many other plant species evaluated, C. aurea extracts did not have repellent properties, but rather had a slight attractant capacity. With 20% and 10% acetone extracts, all ticks were either killed or their mobility severely compromised after 1 μl of extract was topically applied on the abdomen. At a 5% concentration, 85% of ticks were still affected. A 10% aqueous solution also had a marked effect. The results prove the efficacy of the traditional use of this extract and may lead to a product that can be used commercially to protect animals against tick infestation, under subsistence as well as industrialized conditions.