Plant extracts and isolated compounds that are as active as commercial acaricides in controlling ticks in vitro and in vivo

World-wide ticks cause such major problems in tropical areas that if ticks are not controlled by chemical acaricides commercially viable animal production will be impossible. Ticks not only reduce animal productivity by blood loss, but cause many different animal and human diseases transmitted by ticks. Ticks can transmit pathogenic viruses, protozoa, bacteria and rickettsia. Many chemical acaricides in 10 classes have been developed to control ticks. In many cases ticks have developed resistance to acaricides and in other cases acaricides cause serious environmental problems. Rural farmers have no access or cannot afford chemical acaricides and have used many plants to control ticks. Pyrethroids derived from Chrysanthenum species are among the best and safest acaricides and insecticides still widely used. Consequently we have examined many different plant species from different part of Africa using different assays. Our earlier work have led to bioassay-guided fractionation of the most active species has led to the isolation some acaricidal compounds. Two of these compounds isolated from Calpurnia aurea had in vivo activities similar to that of a chemical acaricides. There have been many publications on using plant extracts in vitro to control ticks [1]. One of the major challenges in this field is that there are few publications on live animal studies. Another problem is that in many cases water did not extract compounds that deterred or killed ticks. We could also show that in field experiments a soap extract of Maurea edulis roots could protect cattle against ticks to the same level as a commercial acaricide. This may represent a viable and cost effective way for poor farmers to protect cattle against ticks.

[1] Adenubi OT, Fasina FO, McGaw LJ, Eloff JN, Naidoo V (2016) South Afr. J. Bot. 105,178 – 193