Vol. 6, Issue 7 (2017)

Author(s):
Diaha-Kouamé Amenan Claude Aimée, Yao Kouassi Patrick, Tano Djè Kévin Christian, Azokou Alain And Kouakou Koffi

Abstract:
The evolution of the resistance of the tick Rhipicephalus (Boophilus) microplus to synthetic acaricides gave rise to the need for new scientific research on other ways to control this tick. In this regard, various plant studies have been developed in an attempt to find extracts with acaricidal properties. Aqueous extracts and ethanolic extracts of leaves of Azadirachta indica (Meliaceae), Ricinus communis (Euphorbiaceae), Cymbopogon citratus (Poaceae) and Tithonia diversifolia (Asteraceae) were contacted at different concentrations with R. (B.) microplus. Tests on larvae and engorged females were carried out at concentrations ranging from 25 to 400 mg/ml in the laboratory of the Swiss scientific research center in Adiopodoumé, Côte d'Ivoire. The treatments and controls were carried out in three replicates. At the concentrations of 200 and 400 mg/ml, the ethanolic extracts of these 4 plants were all very active with a mortality rate of 100% of the larvae. The ethanolic extract of C. citratus resulted in the highest mortality at different concentrations with a lethal concentration (LC₅₀) of 35.924 mg/ml. On the engorged females, the aqueous extract of C. citratus induced the strongest inhibition of laying, 58.20% at the concentration of 400 mg/ml. At this same concentration, the extract of R. communis was more active on the hatch with a low hatching rate of eggs (25.06%). The application of these plant extracts showed acaricidal activity against R. (B.) microplus, so it is obvious that the use of plant extracts for the control of this tick is a possible alternative.