Invitro acaricidal effects of ethnoveterinary plants was studied.
Synthesis of ZnO NPs with leaf extract ofLobelia leschenaultianawas carried out.
Acaricidal activity ofLl-ZnO NPs was observed againstR. (B.) microplus.
The present study was designed to investigate the invitro acaricidal effects of seven ethnoveterinary plants, zinc acetate and green synthesized zinc oxide nanoparticles against the Southern cattle tick,Rhipicephalus (Boophilus) microplus. The selected ethnoveterinary plants were extracted using ethanol and aqueous (water) solvents at 0.02 mg/ml and 0.04 mg/ml concentrations. Of these seven plants,Lobelia leschenaultianashowed the highest percentage of tick mortality. The ethanol extracts ofL.leschenaultianashowed 93.33% mortality at 0.04 mg/ml and its LC50was 0.05 mg/ml. However, zinc acetate exhibited 70% mortality at 0.04 mg/ml (LC50: 0.0192 mg/ml). Further, we synthesized ZnO nanoparticle using the leaf extracts ofL. leschenaultianaand zinc acetate as the precursor material to controlR. (B.) microplus. The structural characterization of the synthesized ZnO nanoparticles (Ll-ZnO NPs) was performed by UV- visible spectroscopy, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and transmission electron microsopy (TEM). UV–vis spectra showed the absorption band at 383 nm. XRD analysis clearly showed the crystalline nature ofLl-ZnO NPs with various Bragg's reflection peaks at 100, 002, 101, 102, 110, 103, 200, 201 and 202 planes. FTIR analysis showed the possible functional groups ofLl-ZnO NPs with strong band at 3420.63 and 2922.48 cm−1. SEM and TEM analysis revealed that theLl-ZnO NPs were spherical and hexagonal in shape with particle size ranging between 20-65 nm. The mortality ofR. (B.) microplusafter treatment withLl-ZnO NPs was 35, 57.5 and 82.5% at 0.001, 0.002 and 0.004 mg/ml. On the otherhand, 100% mortality ofR. (B.) micropluswas observed at 0.008 mg/ml (LC50: 0.0017 mg/ml). The results indicated that theLl-ZnO NPs have good acaricidal properties compared toL. leschenaultianaleaf extract and zinc acetate.
R. (B.) microplus;
zinc oxide nanoparticles
Corresponding author at: Department of Animal Health and Management, Alagappa University, Science Block 4th Floor, Burma Colony, Karaikudi 630 004, Tamil Nadu, India. Fax: +91 4565 225202.