Essential oils of indigenous plants protect livestock from infestations of Rhipicephalus appendiculatus and other tick species in herds grazing in natural pastures in western Kenya

摘要

The effects of formulated essential oils of Tagetes minuta and Tithonia diversifolia on Rhipicephalus appendiculatus infesting livestock were evaluated in semi-field experiments. Forty-five zebu cattle naturally infested with ticks were randomly selected from 15 herds, three animals from each. Of the three animals within each herd, one was treated with 1 g of petroleum jelly (control), one with 1 g of essential oil of T. minuta and one with 1 g of essential oil of T. diversifolia on the inner side of ear pinna, the preferred feeding site of R. appendiculatus. Tick infestation on each treated host animal was monitored daily for 18 days by counting the number of ticks attached to the animals. Within 1-4 days post-treatment, the number of ticks on animals treated with essential oils was reduced by more than half the original population. By the 5th day post-treatment, more than 75 and 60% of R. appendiculatus and other tick species, respectively, became dislodged and dropped off. A stronger repellent effect was shown by the essential oil of T. minuta than the essential oil of T. diversifolia. Mean residual protection afforded by T. minuta was 12.5 days and for T. diversifolia 7.9 days. There was no significant difference in the effectiveness of essential oils between male and female R. appendiculatus. Both T. minuta and T. diversifolia essential oils affected several other less dominant but economically important tick species. Results suggest the potential for essential oil formulations in integrated pest management of ticks and associated tick-borne diseases among resource-limited livestock farmers in tropical Africa.