Efficacy of D-Limonene Nanoemulsion Against Rhipicephalus annulatus and Rhipicephalus sanguineus Ticks.

Abstract

Ticks infestation has a negative impact against human and animal health through blood sucking, transmission of blood-borne diseases and also caused economic losses. In the present study the adulticidal, ovicidal and larvicidal activity of D-limonene nanoemulsion (DLN) were evaluated against two tick species; Rhipicephalus annulatus and Rhipicephalus sanguineus. Nanoemulsion form of D-limonene was prepared, and its characteristics were evaluated using a UV spectrophotometer and zeta droplet size measurement. Acetylcholinesterase activity was determined. The results revealed significant adulticidal effect with low LC50 and LC90 for D-limonene pure form (DL) against both adult tick spp. (R. annulatus and R. sanguineus) ((0.958 and 1.559%) and (2.26 and 3.51%), respectively). DLN LC50 and LC90 values were ((1.277 and 2.396) and (3.97 and 7.28), respectively) against R. annulatus and R. sanguineus, respectively. DL and DLN showed significant ovicidal effect against R. sanguineus at high concentrations (10 and 5%). In larval packet test, LC50 and LC90 values of DL were ((1.53 and 2.22%) and (6.81 and 12.07%), respectively) against R. annulatus and R. sanguineus, respectively, while LC50 and LC90 values of DLN were ((6.48 and 11.26%) and (7.82 and 13.59%), respectively) against R. annulatus and R. sanguineus, respectively. Significant acetylcholinesterase inhibition percentage was detected for both ticks spp. which treated by DL and DLN. Pure DL is more effective than DLN form against R. annulatus and R. sanguineus.