Babaçu (Attalea Speciosa) Residue Bio-Oil Repels Livestock Tick Larvae Rhipicephalus (Boophilis) Microplus

Rhipicephalus (Boophilis) microplus (also known as southern cattle tick or Asian blue tick) is one of the most detrimental and prolific tropical cattle parasites. Currently, chemical acaricides used against these ticks have been less effective due to increased pesticide resistance stemming from overuse of these treatments. We propose a novel tick repellent to address the waning efficacy of chemical treatments for R. (B.) microplus on cattle. In the search for an alternative, seven concentrations (100%, 50%, 25%, 12.5%, 6.25%, 3.13%, and 1.57%) of babaçu (Attalea speciosa) residue bio-oil were produced by hydrothermal pyrolysis at 180 °C. The repellency of these bio-oil concentrations was assessed using a tick climbing test. Additionally, toxicity tests were performed by organic chemical analysis and polyaromatic hydrocarbon analysis. The repellency to R. (B.) microplus tick larvae was 100% for concentrations higher than 3.13% babaçu residue bio-oil concentration. However, the 1.57% concentration can be promising even with less repellent effects (though still being 93.7% effective) due to lower toxicity. This is an innovative approach for overcoming drug resistance in these ticks. Future research can test other bio-oils and pyrolysis products as tick repellents and botanical acaricides to further diversify options for better managing these parasites in Brazil and elsewhere in the tropics.