Novel acaricidal efficacy of nine Egyptian plants against the camel tick, <em>Hyalomma dromedarii</em> (Ixodida: Ixodidae)

Ticks are very important ectoparasites transmitting diseases to animals and humans and their natural control is an urgent need. The efficacy of nine novel aqueous plant extracts against Hyalomma dromedarii, semi-fed males, was evaluated through the adult immersion test; seven concentrations were applied (10, 20, 40, 90, 110, 130, and 170 mg/ml) for each plant extract. Plants could be arranged according to their Mortality (MO) percent, 15 days post-treatment (PT) with 170 mg/ml, as follows: 96% by Ricinus communis; followed 84% by Alchemilla vulgaris, Cichorium endivia, Quercus cortex, and Salvia rosmarinus. Three, seven, and 12 days PT, the LC50 values of the highly effective group including R. communis (100.11, 30.34, and 30.22%), A. vulgaris (140.11, 60.94, and 50.38%), C. endivia (120.56, 60.13, and 30.80%), Q. cortex (110.87, 50.05, and 30.13%) and S. rosmarinus (110.73, 50.26, and 40.35%) were calculated. The LT50 values for the highly effective plants were 1.000, 3.136, 2.282, 4.498, and 2.614 days, PT with 170 mg/ml, for R. communis, A. vulgaris, C. endivia, Q. cortex, and S. rosmarinus and their LT99 values were 9.224, 19.840, 19.296, 22.928, and 29.907 days, respectively. The relative toxicity of the A. vulgaris, Allium sativum, C. endivia, Cyperus rotundus, Lepidium sativum, Q. cortex, R. communis, and S. rosmarinus were 1.0, 1.6, 1.6, 1.2, 1.3, 1.7, 1.7, and 12 times, more effective than Lawsonia inermis, respectively. Phytochemical analyses indicated the presence of phenolic, tannin, and flavonoid compounds. This study recommended using R. communis for tick control, followed by Alc. vulgaris, Ci. endivia, Q. cortex, and S. rosmarinus.