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The goal of this work was to assess the in vitro acaricidal effects of Pistacia lentiscus essential oil and its pure active components against red poultry mites Dermanyssus gallinae as an alternative to chemical acaricide (formamidines). Essential oil was obtained using hydrodistillation and then analyzed using GC-MS. The following major components were identified: α-pinene (20.58 %), D-Limonene (18.16 %), β-Myrcène (15.06 %), 4-Terpineol (7.68 %), caryophyllene (5.45 %) and γ-terpinene (5.21 %). The toxicity of essential oil and its six monoterpenes were tested at concentrations ranging from 0.43 to 3.50 mg/cm 2 , using contact and spraying bioassays. Toxicity was expressed as a lethal concentration (LC 50 or LC 90 ). The experiment results revealed that activity was method and concentration dependent, and the spraying method was more effective than the contact bioassay for acaricidal activity. In this bioassay, the highest mortality was observed with 4-Terpineol. The LC 50 was estimated to be 0.184 mg/cm 2 for this substance, followed by α-pinene, the LC 50 of which was estimated to be 0.203 mg/cm 2 . Caryophyllene and γ-terpinene were found less effective in controlling D. gallinae. P. lentiscus oil and its major compounds were also evaluated for anti-acetylcholinesterase (AChE) effects; 4-Terpineol was found to be the most effective AChE inhibitor with IC 50 values reaching 18.73 ± 2.83 µg/mL. This framework pointed out the importance of the traditional use of P. lentiscus as an ecofriendly alternative against ectoparasite of veterinary importance; D. gallinae. In vivo trials should also be conducted to assure the safe use of essential oils or individual compounds and to achieve efficient acaricidal property., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

[Display omitted] • Cupressus sempervirens , Mentha pulegium oil and their combination presented an in vitro acaricidal and repellency effects against H. scupense. • Combination oil is the most toxic compared with plants in individual use. • Essential oils have the potential to be applied as substitute for synthetic acaricides in the management of H. scupense hard ticks. The adulticidal, larvicidal, and repellent effects of Cupressus sempervirens, Mentha pulegium , and their combination (C. sempervirens and M. pulegium) against Hyalomma scupense were investigated, as well as their putative mode of action. The evaluation on H. scupense was performed with the adult immersion test at concentrations ranging from 2.5–20 mg/mL and the larval packet test from 0.625 to 20 mg/mlL. The same concentrations were used for combined oils. Essential oils were obtained using hydrodistillation and then analyzed using GC–MS. The following major components were identified: α-pinene (56.89 %) and δ-3-Carene (15.61 %) for C. sempervirens, while pulegone (70.50 %) and cis-Menthone (18.26 %) for M. pulegium. At 20 mg/mL concentration, C. sempervirens had (94.40 %) acaricide action and inhibited the egg from hatching, however at 10 mg/mL, it had 100 % larvicidal activity. Adulticidal and larvicidal activities of M. pulegium oil reached to 87.19 % and 81.02 % respectively, at 20 mg/mL concentration. The highest acaricidal property against H. scupense was exhibited by combination oils with minimum LC 50 values of 1.76 mg/mL on adultes and 0.60 mg/mL on larvae. The repellent activities were 100, 95.80 and 100 %, at the 20 mg/mL concentration used in 6 h, for C. sempervirens, M. pulegium and mixture oil respectively. Our findings revealed that the mixture of C. sempervirens and M. pulegium, at the ratio 1:1 (v: v) of each oil, showed high synergistic effect (SF > 1) and the use of combination oil (C. sempervirens 50 %: M. pulegium 50 %) is more toxic against H.scupense. Furthermore, the volatile oils examined revealed significant inhibition of H.scupense acetylcholinesterase activity AChE. Based on the findings of the present framework, these essential oils have the potential to be applied as substitute for synthetic acaricides in the management of H.scupense bovine ticks. [ABSTRACT FROM AUTHOR]