Susceptibility of Rhipicehalus (Boophilus) microplus (Acari: Ixodidae) to sulfur and copper nanoparticles

In District Faisalabad, ticks, such as Hyalomma (H) anatolicum Koch and Rhipicephalus (Boophilus) microplus Canestrini (Ixodida: Ixodidae), are significant ectoparasites impacting livestock and wildlife, transmitting pathogens that lead to substantial economic losses. The increasing resistance of tick populations to conventional acaricides necessitates te exploration of potential complementary approaches as control strategies, including nanoparticle formulations. The acaricidal effect of sulfur (S) and copper (Cu) nanoparticles was evaluated against various life stages (eggs, larvae, and adults) of R. (B.) microplus. Nanoparticles were synthesized and characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The susceptibility of ticks to nanoparticles was evaluated by adult and larval immersion tests and larval hatch tests. Ivermectin was used as a positive control. The lethal concentration to 50% mortality (LC₅₀) values for Cu and S nanoparticles against adult R. (B.) microplus were 22.3 ± 3.44 mg/L and 36.16 ± 6.19 mg/L, respectively. At higher concentrations of 80 mg/L (Cu) and 150 mg/L (S), both nanoparticles achieved 99.17% adult tick mortality. S and Cu nanoparticles demonstrated 99.87% and 98.50% larval mortality at concentrations of 150 mg/L and 80 mg/L, respectively. Lower mortality was observed with Ivermectin at 30 mg/L, with 66.67% adult mortality and 61.50% larval mortality. Cu and S also resulted in 99.87% unviable eggs at concentrations of 80 mg/L and 150 mg/L, respectively, while Ivermectin led to only 90.63% unviable eggs. S and Cu nanoparticles exhibited significant potential as effective complementary agents to traditional acaricides, disrupting the life cycle of R. (B.) microplus. Further research is essential to assess their long-term ecological impacts and safety for non-target organisms.