Acaricidal effect of herbal extracts against cattle tick Rhipicephalus (Boophilus) microplus using in vitro studies

The crude methanolic extract of Datura stramonium, Azadirachta indica, and Calotropis procera leaves, Allium sativum (AS) cloves, and Carica papaya (CP) seeds collected from Banaskanta, Gujarat (India) was tested for its acaricidal properties against Rhipicephalus (Boophilus) microplus. The percent adult mortality within 15 days, reproductive index, percentage inhibition of oviposition, hatching of laid ova, and percentage larval mortality were studied at concentrations of 12.5, 25, 50, and 100 mg/ml. At the highest concentration (100 mg/ml), the adult tick mortality was 66.67, 73.33, 80.00, and 93.33% for C. procera, D. stramonium, A. sativum, and C. papaya extracts, respectively, and it was statistically significant (P < 0.001). However, for A. indica, mortality was low and estimated to be 33.33%. Inhibition of oviposition at the highest concentration of A. indica, C. procera, D. stramonium, A. sativum, and C. papaya extract-treated ticks was 20.73, 71.34, 77.17, 85.83, and 100.00%, respectively. Inhibition of fecundity of treated groups differed significantly from the control and was concentration dependent. Larvae treated with all the tested concentrations of A. indica, C. procera, D. stramonium, A. sativum, and C. papaya extracts by larval packet test showed significant mortality (P < 0.001) than that of control tick larvae, and at the highest concentration, it was 55.2, 63.2, 71.8, 69.0, and 82.2%, respectively. Garlic cloves and papaya seed extract produced complete failure of eclosion of eggs from the treated ticks even at lower concentrations; however, neem, calotropis, and datura was capable of reducing hatchability by 20, 50, and 70%, respectively. The results pointed that the crude extracts of A. sativum cloves and C. papaya seeds have very good acaricidal properties and could be a potential component of alternative R. (B.) microplus tick control strategy.