In vitro acaricidal activity of crude extracts of Schinus molle (L.) leaves against field population of Bophilus decoloratus and Rhipicephalus pulchellus ticks

Abstract

Plant products are a rich source of bioactive organic chemicals and offer an advantage over synthetic pesticides as these are less toxic, less prone to development of resistance and easily biodegradable. The present study aimed at screening the acaricidal potential of crude methanolic and aqueous extracts of Schinus molle (L.) leaves on the adult Bophilus decoloratus and Rhipicephalus pulchellus cattle ticks, using in vitro immersion method. Freshly collected adult ticks were exposed to three graded concentrations of the crude extracts; 1% (1g/100ml), 2% (1g/50ml), and 4% (1g/25ml) for 24 h and mortality rates were recorded post exposure for each concentration every 3 h. Diazinon (0.2%) and distilled water were used as positive and negative controls respectively. Acaricidal activities of each concentration were measured by mean number of ticks died and antiparasitic efficacy (%) relative to the negative control. Analysis result indicated that highest (4%) and middle (2%) concentrations of both extracts caused a statistically significant (P<0.05) killing effect on R. pulchellus and B. decoloratus for most of the observation hours as compared to the extract unloaded in vitro groups. The relative antiparasitic efficacy (%) was highest for 4% concentration of both extracts (100%). The standard acaricide failed to completely eliminate the parasites after 24 h of exposure although it showed a slightly better effect against B. decoloratus (96.7%) compared to R. pulchellus (93.3%). Put together, this finding showed that the crude extracts of the plant have promising acaricidal properties and warrant further investigation