Control of Rhipicephalus annulatus resistant to deltamethrin by spraying infested cattle with synergistic eucalyptus essential oil-thymol-deltamethrin combination

The current study investigated the synergistic effect of combinations containing deltamethrin (D), Eucalyptus essential oil (E), and thyme component thymol (T), against a field population Rhipicephalus annulatus in Egypt that was characterized to be resistant D. Solutions T, E, or TE at concentrations 1.25–5% were combined with 5% different dilutions (0.25–2 mL/L). Results adult immersion test used estimate vitro acaricidal activity these yielded LC50 values for D, E-D, T-D, TE-D 3.87 mL/L, 3.89 0.14 0.05 respectively. Biochemical analyses using whole-body homogenate ticks from tests revealed lowest acetylcholinesterase glutathione peroxidase activity, maximum lipid peroxidation recorded treated TE-D. Glutathione content significantly decreased (p ? 0.05) all ticks. Three groups, each five cross breed cattle naturally infested R. same area where resistance D detected, sprayed twice two-week intervals 1 mL/L solutions Overall efficacy sprays by day 30 post-treatment 21.6, 88.3, 95 %, Ticks collected three days after treatment spray deposited egg masses able hatch, small eggs unable hatch when exposed T-D spray, laid few didn’t combination. Values liver kidney function parameters comparable before combination tested. overcame insensitivity this Egypt, which also highlighted significant on observed vitro. Acaricidal apparently has deleterious effects multiple tick systems involving inhibition acetylcholinesterase, increased peroxidation, oxidative stress. These findings document natural synthetic products can part integrated management problem widespread pyrethroids like populations ticks, including annulatus, around world.