MORPHOLOGICAL AND MOLECULAR CHARACTERIZATION OF TICKS FROM CAMELS IN QATAR: EFFECTS OF OZONE AND PROSOPIS JULIFLORA ON TICK STRUCTURE AND SURVIVAL

Abstract

Ticks are important vectors of diseases that harm humans and animals, resulting in severe economic and health consequences: environmental issues and the emergence of resistance result from the extensive use of synthetic acaricides. Prosopis juliflora and other plant-based extracts offer a viable, environmentally beneficial substitute for long-term tick management and control. Tick samples were collected from camels between February 2024 and January 2025 from several animal farms distributed across Qatar at different municipalities, to be identified morphologically and molecularly to the species level. Engorged female ticks were exposed to ozone (O3) gas to evaluate any possible structural abnormalities in the tick's cuticle. Then, to assess oviposition inhibition (%) and death rates, an adult immersion test (AIT) was performed on both engorged and unfed female ticks using varying doses of Prosopis juliflora extract. The effectiveness of the plant extract and its effect on tick survival were examined statistically using R software and the GLM model. A total of 4035 tick specimens were collected and examined, and two species of ticks were identified as Hyalomma dromedarii (n=3942) and, as a first record in Qatar, Rhipicephalus (Boophilus) annulatus (n=93). This study showed that some environmental factors can contribute significantly to both tick count and male-to-female ratio, such as temperature and humidity. Furthermore, P. juliflora's acaricidal ability against H. dromedarii was assessed at all tested doses (0.05 mg/mL to 0.5 mg/mL). According to the dose-response analysis, an effective concentration of 0.04 mg/ml was enough to kill 50% of the ticks, and the survival probabilities of the untreated ticks were 1.72 times greater than those of the treated groups. Following the ozone gas application, all of the engorged females in the ozone-treated group were dead and displayed further lesions on their cuticles and respiratory spiracles, which suggests that ozone can be proposed as a solution for tick spreading. Future research should explore varying doses, identify key bioactive constituents, and assess the effects of P. juliflora across all tick life stages. Additionally, ozone treatment should be evaluated at different concentrations and across tick developmental stages, accompanied by comprehensive toxicity assessments in different host animals, including camels.