Abstract
A layered double hydroxide (LDH) incorporated with Ocimum basilicum essential oil (OB) was prepared and its acaricide Delivered by Ingenta efficacy against Rhipicephalus annulatus tick was investigated. The OB essential oil was extracted from plants farmed the study area. Zn-Al LDH/Gallate was prepared by co-precipitation method then OB oil was added to obtain OB/LDH nano-composite. The obtained product was characterized by X-Ray Diffraction (XRD), Fourier-transform infrared (FT-IR) and scanning electron microscopy (SEM). The acaricidal activity of different concentrations of the obtained OB/LDH nano composite (6.25, 12.5, 25, 50, 100, 200 and 300 mu l/mL) was evaluated via the adult immersion test (AIT), egg hatchability test (EHT), larval packet test (LPT) and repellency test. OB oil and OB/LDH nano-composite showed 100% adult mortality and prevent egg deposition at a dose of 300 mu l/mL. Also, eggs hatching was fully inhibited at 300 mu l/mL while at the concentration of 200 mu l/mL the inhibition rate was 95%. In LPT, OB/LDH showed a high toxicological effect which leading to 100% and 43% larval mortality at doses of 200 mu l/mL and 100 mu l/mL, respectively. Meanwhile OB alone showed 100% and 45% larval mortality at doses of 300 mu l/mL and 200 mu l/mL, respectively. The LC50, LC(9)0 and LC99 values of OB/LDH and OB were found to be 107.46 versus 209.908 mu l/mL, 171.22 versus 282.63 mu l/mL and 196.15 versus 298.26 mu l/mL, respectively. The repellence activity was lasted for 3 h after application against larvae. OB/LDH was found to be more repellent than OB as evidenced by the RC50 values after 2 h and 3 h (48.82 vs. 79.99 mu l/mL and 89.47 vs. 185.32 mu l/mL, respectively). Overall, our results proved that LDH enhanced the larvaicidal and repellent efficacy of OB against R. annulatus tick larvae.