“…The role of secondary metabolites of plants such as phenols, flavonoids, terpenoids, alkaloids, essential oils, quinones, tannins, saponins and sterols in eliciting defense against pests is well known. The extracts of many plants with promising acaricidal properties were reported from our laboratory too [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. In addition to their direct acaricidal activity due to neurotoxicity, many herbal extracts produced accelerated degeneration of salivary glandular tissue and changes in the morphophysiology of reproductive organs in ticks [ 19 , 20 ].…”