Abstract:
The acaricidal activity of acetone and ethanol extracts of 12 plant species was evaluated using
the contact method on Rhipicephalus turanicus (Acari: Ixodidae) ticks at an initial concentration
of 20% (200 mg/mL). Eight of the 12 plants had mortality greater than 50% and the acetone
extracts had better acaricidal activity than the ethanol extracts. The acetone extract of Calpurnia
aurea (leaves and flowers) had the highest corrected mortality (CM) of 92.2% followed by
Schkuhria pinnata (whole plant) with a CM of 88.9%, Ficus sycomorus (bark and stems) 86.7%
and Senna italica subsp. arachoides (roots, leaves and fruits) 83.3%. Selected extracts were tested
at five different concentrations using the adult immersion test. From dose–response assays,
EC50 values of 61.82 mg/mL, 115.21 mg/mL and 161.02 mg/mL were obtained for the acetone
extracts of S. pinnata (whole plant), S. italica subsp. arachoides (roots, leaves and fruits) and
C. aurea (leaves and flowers) respectively. The ethanol extract of Monsonia angustifolia (whole
plant) had the highest CM of 97.8% followed by S. pinnata (whole plant) with a CM of 86.7%,
C. aurea (leaves and flowers) 81.1% and Cleome gynandra (leaves) 77.8%. There is potential
for the development of environmentally benign botanicals as natural acaricides against
R. turanicus.
