We aimed at determination of acaricidal, larvacidal, and repellent activities of green synthesized silver nanoparticles (SNP) against Hyalomma dromedarii as one of the most common ticks in camels. SNP were green synthesized by reducing Lupinus albus extract through the precipitation technique. The acaricidal, larvicidal, and repellent activity of SNP against H. dromedarii was studied through the adult immersion test (AIT), the larval packet test (LPT), the vertical movement behavior of tick's larvae method, anti-acetylcholinesterase (AChE) activity, and oxidative enzyme activity. The green synthesized SNP displayed a spherical form with a size ranging from 25-90 nm; whereas the most distribution of particles size was reported at 50-65 nm. SNP dose-dependently (p<0.001) increased the mortality rate of H. dromedarii adult; whereas at 16 and 32 µg/mL completely killed the adult females. Treatment of exposure of H. dromedarii adult to SNP markedly (p<0.001) declined the mean number, weight, and hatchability of eggs. Treatment of H. dromedarii larvae with SNP reduced the viability rate of larvae with the LC50 and LC90 values of 3.1 and 6.9 µg/mL, respectively. Exposure of H. dromedarii larvae to SNP, especially at ½ LC50 and LC50, markedly (p<0.001) increased the oxidative stress and declined the level of antioxidant enzymes in H. dromedarii larvae; whereas, markedly suppressed the AChE activity of the larvae stage of H. dromedarii in comparison to the control group. These results showed that SNP green synthesized by L. albus extract had promising acaricidal, larvicidal and repellent activity against H. dromedarii adults and larvae as a dose-dependent response. SNP also considrably decreased the level of acetylcholinesterase and antioxidant activity and also provokes oxidative stress in H. dromedarii larvae. However, more investigation must be designed to clear the accurate mechanisms and the efficacy of SNP in practical use.
Current strategies for tick control have led to the development of resistance and environmental contamination. Consequently, there is an urgent need for research into new and effective acaricides for tick control. The aim of this study was to fabricate and characterize Linalool loaded zinc oxide nanoparticles (Lin@ZNP), and to assess the acaricidal, larvacidal, and repellent activities of Lin@ ZNP against Hyalomma anatolicum, a prevalent tick species infesting cattle in Saudi Arabia. Lin@ ZNP was synthesized using an ethanolic solution of polyvinyl alcohol. The adult immersion, the larval packet, and the assessment of vertical movement behavior of tick larvae assays were utilized to examine the acaricidal, larvicidal, and repellent activities of Lin@ZNP against H. anatolicum, respectively. Furthermore, the impact of Lin@ZNP on acetylcholinesterase and oxidant/antioxidant enzyme activities was investigated. Exposure of adult H. anatolicum to different concentrations of Lin@ZNP resulted in noticeable (p<0.001) reductions in the viability rate of adults and the mean number, weight, and hatchability of eggs, compared to the control group. Lin@ZNP demonstrated significant repellent effects on H. anatolicum larvae after 60, 120, and 180 minutes of exposure. Lin@ZNP, particularly at all concentrations, markedly suppressed the acetylcholinesterase activity of the larval stage of H. anatolicum (P<0.001); but increase in malondialdehyde (MDA) levels (P<0.001) and a decrease in glutathione-S-transferase (GST) levels in H. anatolicum larvae (P<0.001). Lin@ZNP exhibited considerable acaricidal, larvicidal, and repellent effects against H. dromedarii adults and larvae in a manner dependent on the dosage. Additionally, Lin@ZNP notably reduced AChE levels and antioxidant activity, while inducing oxidative stress in H. anatolicum larvae. Nevertheless, further research is necessary to elucidate the precise mechanisms and practical efficacy of Lin@ZNP.