Abstract
BACKGROUND: Hyalomma rufipes (H. rufipes) ticks are widespread in Africa, Europe, and Asia. They transmit crimean-congo hemorrhagic fever virus, rickettsia, and midichloria, posing a significant risk to public health and livestock development. Developing acaricides based on plant essential oils (EOs) have risen, yet matters regarding their mechanism and feasible methods for tick tests remain unanswered. The aim of this study was to identify the chemical constituents of three EOs and evaluate their acaricidal activity against larval and adult ticks of H. rufipes, as well as to establish an artificial membrane feeding technique to explore the feasibility of Cinnamomum mollifolium EO for tick control in vitro. RESULTS: In this study, gas chromatography-mass spectrometry (GC-MS) was used to analyze the constituents of C. mollifolium, Eucalyptus globulus, and Pimenta dioica EOs, as well as to investigate their potential application in H. rufipes control. The main compound in C. mollifolium EO is (E)-Cinnamaldehyde (93.15%). Eucalyptus globulus EO comprises eucalyptol (61.02%) and l-(+)-Ascorbic acid 2,6-dihexadecanoate (35.89%). Pimenta dioica EO predominantly includes eugenol (73.67%), 1,2-dimethoxy-4-(2-propenyl)-benzene (13.04%), and caryophyllene (7.24%). Larval packet tests revealed that the EOs of C. mollifolium, E. globulus, and P. dioica exhibited notable larvicidal activity, with lethal concentration (LC(50)) values of 8.84, 51.16, and 34.58 mg/ml, respectively. Adult immersion tests indicated that the EOs of C. mollifolium, E. globulus, and P. dioica had significant acaricidal activity against adult ticks, with LC(50) values of 15.51, 43.96, and 29.83 mg/ml, respectively. Artificial membrane feeding technology enabled successfully in vitro rearing of adult male and female ticks with attachment rates of 83.4% and 75.0% respectively. The most effective EO (C. mollifolium) was applied on ticks after attachment to an artificial membrane, and showed acaricidal activity with high adult mortality at higher concentrations. CONCLUSION: This study offers useful information on the chemical makeup and tick-killing ability of essential oils from C. mollifolium, E. globulus, and P. dioica against ticks. The acaricidal potency of C. mollifolium EO significantly surpasses that of both E. globulus and P. dioica EOs. The effective use of artificial membrane feeding technology also highlights its value for future tick control research and applications.